Researching the Luftwaffe through Prisoner Interrogations

[Bruce Dennis]

"A. D. I. (K) Report No. 334/1945
THE FOLLOWING INFORMATION HAS BEEN OBTAINED FROM P/W AS THE
STATEMENTS HAVE NOT AS YET BEEN VERIFIED, NO MENTION OF
THEM SHOULD BE MADE IN INTELLIGENCE SUMMARIES OF COMMANDS OR LOWER FORMATIONS, NOR SHOULD THEY BE ACCEPTED UNTIL COMMENTED ON AIR MINISTRY INTELLIGENCE SUMMARIES OR SPECIAL
COMMUNICATIONS.

THE GAF SIGNALS ORGANISATION IN THE WAR.
1. This report results from the interrogation in England of
General der Nachrichtenführer MARTINI, the Director General of
G.A.F. signals from the time of the formation of the Luftwaffe
until the end of the war. A feature of this interrogation was
General MARTINI's rather surprising lack of detailed knowledge
of signals and radar equipment in use in the Luftwaffe, but
his knowledge on matters of broader policy of the signals
organisation was naturally considerable.
2. The gap in his detailed knowledge has to some extent been
filled by the chiefs of his subordinate formations, and it is
intended in due course to issue a further report dealing with
employment of radio and radar equipment. The present report
confines itself to the main events during the war as they
concerned the signals organisation, and shows that General
MARTINI himself was not free from the intrigues which beset
the whole of the General Staff.
3. The information has been divided into five parts, each of
which is, as far as possible, dealt with in historical
sequence; the parts are:-
1. Expansion of the G.A.F. Signals Organisation.
2. Navigational aids for G.A.F. bombers.
3. Defensive radar.
4. The success of Window.
5. Wireless intelligence and Signals developments.

I - EXPANSION OF G.A.F. SIGNALS ORGANISATION.
4. To meet the growing needs of the G.A.F., General MARTINI
developed the Signals Organisation from a small force with
about 300 active officers at the outset of the war, to an army
of about 350,000 of which 10,000 were officers and 100,000
women.
5. In the early autumn of 1940, GOERING, appreciating the
part played by G.A.F. signals, ordered the force to be
doubled. As Germany conquered fresh territories the Signals
Organisation had to be constantly expanded.
Early Campaigns.
6. General MARTINI was of the opinion that all the early
German campaigns were prepared with great speed. When the
German marched into Austria, he and General Feldmarschall von
REICHEMACH were at a radio conference in Cairo. Neither of
them had the slightest idea that Austria was to be invaded.
They were both informed at Cairo that German troops had
marched into Austria. Similarly, General MARTINI heard only at
the last minute that German troops were to invade
Czechoslovakia.
7. Some days before the Polish Campaign was opened, German
land-air exercises were being carried out on a large scale,
and the G.A.F., signals organisation was assuring interservice
communications, in particular between RICHTHOFEN's
Stukas and the Army. On the outbreak of war considerable
strain was put on G.A.F. Experimental Regiment KOETHEN at the
last minute, so as to ensure satisfactory communications for
the Stukas in Poland. The British declaration of war came as a
general surprise and created great uneasiness.
8. General MARTINI was emphatic in maintaining that he was
informed of the intention to invade Norway only six to eight
days in advance. He doubted whether HITLER had told more than
a very few people of his intentions beforehand and he asserted
that everybody appeared to be taken by surprise as
arrangements were kept "terribly secret".
9. As soon as General MARTINI was informed of the intended
campaign, he flew to his headquarters in Hamburg and selected
his best officers for organising communications. They worked
at high speed day and night for six days. The organisation
proved exceptionally difficult because all the details of the
plan had to be kept secret. It was decided that the Army Navy
and Luftwaffe would all work on the same frequency at the half
dozen points where landings were to be effected.
10. Every Ju.52 which the G.A.F. signals organisation could
lay its hands on was transformed into a signals aircraft, and
communications Trupps were also sent out on all the transport
ships. The success of the G.A.F. communications, the General
considered was largely due to the Ju.52 signals aircraft.
Invasion of Britain.
11. General MARTINI would not commit himself about the time
at which preparations were first made to invade England. Once
the Germans held the Channel ports a plan was evolved under
the cover-word "Seelöwe" by which barges were assembled in the
Channel Ports. The whole plan was so decentralised, however,
that the various departments knew only what directly concerned
them. For a long time General MARTINI had the impression that
the whole plan was a feint. He estimates that the General
Staff worked seriously on the invasion plan for two to three
months.
12. The plan comprised landings in two different places, but
he maintains that he was never told what these places were,
and he is not aware that any date was fixed for the invasion.
He is certain that if the date for the invasion was fixed and
the plan called off, then the High Command deliberately kept
up the fiction that it intended to invade England for months
after the whole thing had been shelved.
Russian Campaign.
13. Support was given to the above contention by the General
when he stated that he was informed at least six months ahead
of the High Command's plan to invade Russia. Since the Germans
wished to avoid fighting on two fronts, the plan to invade
England must have been postponed indefinitely at any rate
before 1941. When he was informed of the Russian invasion
plan, General MARTINI discussed his requirements at a
conference with HITLER.
14. This was one of the two or three occasions on which he
had personally to report to HITLER. He worked out a plan to
build six lines of communication advancing into Russia, each
manned by one signals regiment. This required a considerable
amount of material and transport. Generaloberst JESCHONNEK
appreciated that General MARTINI’s requirements were
justified, but the Army put up objections.
15. At the inter-service conference with HITLER which ensued,
General MARTINI stated his case. "How quickly will you be able
to construct your lines of communication?" HITLER asked him.
MARTINI replied "30 kilometres a day". HITLER interposed;
"That is far too little. Forty kilometres of railway will be
built per day!".
16. MARTINI said that by putting down one telegraph line
instead of two, he could assure the construction of more than
40 kilometres a day. HITLER then sanctioned all his
requirements, telling the other services not to under-estimate
the value of signals communications.
17. A unified method was adopted for signals construction in
the Russian advance; field cables were first laid, then
ordinary telegraph wires. Inter-service and fast communication
such as Met. reports were sent by wireless. The system of
G.A.F. Army Liaison officers used in Russia was modelled on
that worked out by the Germans in the Spanish war.
18. Telegraphic communications were as a rule reserved for
communications between O.K.L. and the Luftflotten, between the
Luftflotten and the Fliegerkorps, and between the Fliegerkorps
and Army Staff.
19. The German land lines were tapped by the Russians.
General MARTINI regretted that the Germans had never succeeded
in making a secure telephone scrambler. Ha said that towards
the end of the war a satisfactory apparatus was found in a
British or American aircraft. He had it tested and found it
good.
20. Land lines in Russia also suffered considerably from
partisan action. They were guarded every 30 to 50 kilometres
by posts of 8 to 12 men, but guard duties were particularly
difficult in forested country. When one line was cut,
communications were switched onto one of the other lines or
put over wireless links. Despite these difficulties, regular
communications were maintained throughout the campaign.

II – NAVIGATIONAL AIDS FOR BOMBERS.
Development of Bombing Beams.
21. At the beginning of the war the G.A.F. tended to neglect
its defensive organisation and concentrated on the offensive,
General MARTINI was not responsible for navigation as such,
but for high frequency radio as an aid to navigation. In 1933
he had calculated that with the navigational aids at his
disposal, mainly D/F and compass, he could obtain an accuracy
of only about 50 kilometres at is distance of 500 kilometres.
22. At the end of 1933, Dr. PLENDL, who had been introduced
to him by the Technisches Amt, told him that if the funds were
placed at his disposal he could in some years' time produce, a
navigational aid with an accuracy of 500 metres at a distance
of 500 kilometres, Feldmarschall MILCH placed the means at his
disposal. After several years PLENDL completed his apparatus,
and experiments were conducted on the X-System by Versuchs
Regiment KOETHEN with the bomber Gruppe which later became
K.G. 100.
23. The first operations of the war with mobile X-Stations
were on two bombing missions against a munitions factory in
Poland. The factory vas foolishly bombed at the same time by
ordinary bombers, so that the experts were unable to determine
whether or not the X-System was a success.
24. The campaign was over so quickly that no other
operational trials with X-beams on Poland could be made.
Knickebein Beams.
25. After the Polish campaign, Knickebein and X Stations were
constructed opposite the German-French frontier in preparation
for the Western offensive. Kampfgruppe 100 was by that time
thoroughly trained in the beam procedure, and many highly
specialised Signals officers had been incorporated in the
Gruppe as navigators.
26. The Norwegian campaign then took place, and Kampfgruppe
100 was thrown into it as an ordinary bomber unit. Most of the
crews were killed, and the Gruppe was wasted. The specialists
were scarcely required for the French campaign, but the Gruppe
had to be re-formed completely with lesser trained crews for
the attack on England.
27. The Knickebein system was used at the outset of the
attack on England. The apparatus on the Channel coast had been
hurriedly set up, however, and there were neither sufficient
technicians nor material to make conclusive tests. Dr. MODEL,
a former Reichspost official who died during the war, was
taken over by the wireless department of the signals
organisation and was chiefly responsible for developing
Knickebein in collaboration with the Technisches Amt and
Telefunken.
28. The crews using Knickebein soon reported that the beam
was being diverted, and that British fighters were being
vectored on to it. Several weeks were required to prove that
the beam was really being diverted. After some weeks,
experienced signals officers were sent out with the bombers
and reported that countermeasures had in effect been taken by
the British.

"X" and Benito Bomber Beams.
29. Dr. PLENDL invented both the "X" and "Y" (Benito)
systems. The "X" beams were developed under the signals
organisation at Köthen by Dr. KÜNHOLD with K.G.100 and General
- then Oberst - ASCHENBRENNER, an old and experienced pilot.
The Benito system, on the other hand, was perfected by Dr.
PLENDL at the Technisches Amt under Feldmarschall MILCH, and
General MARTINI had nothing to do with it.
30. It was intended to train a whole Geschwader to navigate
on the "X" system. After Kampfgruppe 100, acting as
pathfinders for large bomber forces, had been attacking towns
in Great Britain on the "X" system for a short time, however,
Dr. PLENDL wanted to try out Benito in practice, which he
regarded as the better system.
31. At that time Oberst ASCHENBRENNER's younger brother, who
was the Kommandeur of Kampfgruppe 100, was ordered to take
over III/K.G.26 which had been intended to fly also on "X".
Dr. KÜNHOLD always considered the "X" system better than the
Benito, and was annoyed with Dr. PLENDL for introducing and
pushing the Benito system.
32. P/W from III/K.G.26 stated in 1940 that the Benito system
was introduced prematurely because of the countermeasures
which the British had been taking against the "X" beam.
General MARTINI, however, maintains that the causes for the
early introduction of Benito were more complex. He said that
he had been responsible for putting into practice the use of
beams as navigational aids for bombers, and that he had
considerable difficulty in overcoming the objections of the
pilots and their commanders.
33. The pilots maintained that they could obtain better
results by finding the targets themselves, and those who were
obliged to follow the pathfinders felt that they were being
relegated to subsidiary tasks. They reported that K.G.100 had
bombed in the wrong place, and that they had found the right
target by themselves. Despite the good results obtained with
"X", anger against the system remained unabated.
34. The aim of operating two whole Geschwader on beams
against England was not achieved because of initial distrust
and British countermeasures and later because the bombers were
earmarked for the Russian campaign. The Benito system suffered
chiefly from British interference of the R/T.
35. General MARTINI himself realised from the outset that the
beams could be interfered with from Britain, and favoured the
introduction of several systems to make countermeasures more
difficult.
36. Thus, in the light of later experience, the Benito system
was introduced prematurely. The General points out that this
was only the beginning of the high frequency war, and they
lacked experience about the best measures for forestalling
countermeasures.
37. When KG.100 was achieving its successes, GOERING enquired
as to who was responsible for the "X" system. On hearing from
MARTINI during a long talk on navigational aids that PLENDL
had invented it, he said: "Then I shall promote him to
Staatsrat!" (State Councillor). GOERING could not understand
how the system had been jammed. MARTINI spent two hours trying
to explain the procedure of jamming and countermeasures.
GOERING asked a number of questions, but was afterwards
clearly none the wiser. He grew very angry, and accused
MARTINI of fiddling about with patchwork measures.
38. In reading the above statement it must be emphasised that
General MARTINI was sometimes confused in his memory between
the "X" and "Y" systems.

Mobile "X" Stations in Russia.
39. Kampfgruppe 100 later flew in Russia with mobile "X"
stations, which were set up with great speed.

Cyklop System.
40. Towards the end of 1943, the Knickebein system was
developed on a new basis with mobile stations under the cover
name CYKLOP. This system was used extensively by Fliegerkorps
IV, in Russia and was to have been set up on the Channel coast
for attacks on England, but the General was not sure whether
it was actually used.
41. Cyklop had a range of 300 to 350 kilometres as against
the 450 kilometres of Knickebein. It was developed by Dr.
KÜNHOLD at Köthen.

Hitler Demands a Demonstration of the "X" Beam.
42. About the summer of 1942, when General MARTINI was at his
headquarters in South Russia, he was suddenly ordered to fly
over to Hitler’s general headquarters near Kalinovka some 12
miles away. HITLER had heard that the Krupps works had been
hit in an attack at night throw ten-tenths cloud by R.A.F.
bombers flying with navigational aids. He could not believe
it, and said that there must have been a gap in the clouds;
GOERING was troubled, and General JESCHONNEK - his Chief of
Staff, who also had no faith in high frequency aids, was also
sceptical. So HITLER ordered them to call in MARTINI.
43. Asked by HITLER whether such accurate bombing was
possible on beams, MARTINI said it was. GOERING, who saw
trouble ahead for himself, interposed saying: "Yes, my Führer,
but we also have such systems."
44. HITLER asked MARTINI how the "X" system worked. In an
attempt to simplify the explanation, MARTINI spoke about
impulses and echoes. HITLER asked for more and more details,
calculating for himself everything that MARTINI explained. The
General thus found himself thoroughly involved and confused.
45. "Now I want to know", HITLER said with some impatience,
"if you were to attack Munich main railway station from
Leipzig on your system, whether you could hit it?" MARTINI,
taking good care not to commit himself too deeply, said; "I
should estimate that Munich is about 400 kilometres from
Leipzig. If that is correct, and if the station is 1,000
metres long by 300 wide, then I believe that some of the bombs
would hit the target."
46. HITLER replied: "I hope this is correct. I don't trust
high frequency. I went on a flight in South Germany, and ended
up in North Germany by mistake with your high frequency." He
reflected for a moment and said: "I order a demonstration to
be carried out with the "X" System in Germany, just as if it
were an operation, to show me whether these things really can
be done.
47. This was the last that MARTINI heard on the subject from
HITLER himself, but a long time afterwards he was rebuked by
GOERING for taking so long to prepare the demonstration;
preparations actually took about nine months.
48. At the time the "X" apparatus was undergoing trials for
improvements, and the aircrew who had used airborne apparatus
had to be replaced in the aircraft, the "X" stations set up in
the neighbourhood of Vienna, and new pilots trained. General
MARTINI did not know all details of the trials, since they
were put into the hands of Dr. PLENDL and the Air Officer for
Bombers who was also Inspector for Navigation.
49. The actual bombing demonstration flight was from Austria
to an unpopulated spot near Grafenwöhr in the neighbourhood of
Bayreuth, and was a success, but it cost enormous effort.

Disappointment over Erika.
50. Explaining why "Erika" stations had been built on the
Channel coast but had not been used, General MARTINI said that
the system proved far more difficult to perfect than had been
supposed.
51. Moreover it necessitated a large airborne apparatus, and
a very large ground installation, and this took years and
years. In the final stages an inaccuracy was observed which
had been previously overlooked.
52. There was besides the continual danger that it could be
easily jammed. "I worried a great deal over it", the General
said.
53. Professor von HANDEL, whose great passion it was, had
claimed that it would be more accurate than the "X" system. He
worked at it as feverishly as PLENDL worked on his "X" system.
54. The two men fell out and MARTINI went to great pains to
get them to work together, and finally succeeded. He hoped
that they would combine the "X" and "Erika systems, but this
never happened.

Sonne Beacons in Spain.
55. Talking of other air navigation systems, General MARTINI
said that besides using Sonne beacons themselves in Spain, the
Germans made over some Sonne apparatus to the Spaniards.

III - DEFENSIVE RADAR.
First Information on British Radar.
56. Discussing British and German ground radar, General
MARTINI said he was aware before the beginning of the war that
great radar stations had been put up on the coast of England,
and that they had very long range. It was known that the
impulses were 25, 50 and 1000, and that height measurements
could be obtained. It was not known whether the radar could
really determine the number of aircraft approaching.
57. Just before the war the Graf Zeppelin flew along the
coast of England during an experimental flight. The main
object of that flight was to test ultra-short wave receivers.
Incidentally it was thought that British radar stations might
be D/F'd. General MARTINI said he did not know exactly what
experiments were made during the flight, but he had heard that
the high frequency receivers were not satisfactory, and
results were uncertain.

First German Radar.
58. In General MARTINI’s opinion, the two men chiefly
responsible for the invention of radar in Germany were Dr.
RUNGE, of Telefunken, who worked on a 50 to 60 centimetre
wavelength, and Dr. SCHULTES, of GEMA, who worked chiefly with
80 centimetre and 2.4 metre waves.
59. Radar apparatus was first developed in Germany by the
Naval Experimental Institut and GEMA in 1936 or earlier.
General MARTINI was shown a Freya by the Navy, and saw that it
could achieve results over the sea. He hoped that the G.A.F.
would be successful with it over land and foresaw that it
could have a great feature in aircraft reporting, blind
landing and other spheres.
60. Just before the invasion of Czechoslovakia he had a Freya
placed in the Sudeten mountains. "I hoped", he said "that with
our Freya in the mountains we would be able to pick up
aircraft taking off in Czechoslovakia, but we failed to obtain
any results".
61. At about the same time the firm of Telefunken began
trials with Würzburg apparatus. They claimed that it could
pick up aircraft, but their demonstration failed.
62. The General said that he had ordered about 200 Freyas and
800 Würzburgs for the G.A.F. before the war, but he had
obtained only a small number by the time hostilities had
begun. A very few Freyas were set up on the North Sea coast
and these worked satisfactorily, being instrumental in causing
heavy R.A.F. losses over Heligoland in the bombing attacks in
1939.
63. Freyas were not used during the Norwegian campaign, but
were set up after the Luftwaffe had established itself on the
Norwegian coast. The signals organisation was obliged to hand
over all the Würzburgs intended for the aircraft reporting
system to the Flak arm, because the radar apparatus brought
out by Lorenz which was used for Flak aiming had proved a
failure.

Fighter Control.
64. From the reports of his Signals Intelligence Service, the
General concluded that the R.A.F. aircraft reporting system
and radar were used principally to aid the ground control of
fighters. For a long time the Luftwaffe was unable to organise
ground control of day fighters, because of the opposition of
most of the pilots, who insisted on free-lance fighting.
65. The change was introduced very slowly and was influenced
by the discovery by the German Signals Intelligence Service
that the R.A.F. was using Pip-Squeak. The Pip-Squeak aircraft
apparatus was later captured. The procedure seemed a good idea
to the German pilots, who wanted a Pip-Squeak of their own,
and began to realise the advantages of fighter control.
66. Actually, German industry had for a long time been
working on a similar apparatus, but failed to bring out a
satisfactory one. Later the Pip-Squeak apparatus was copied by
the Germans, but it was never used operationally.
67. The organisation of radar for fighter defence suffered
both before and during the war from inter-departmental
difficulties and intrigue.
68. The main reason why radar was not developed earlier for
ground control of fighters, General MARTINI said, was that
until the summer of 1941 the Luftwaffe concentrated on
offensive tactics to the neglect of fighter defence. The
decision to subordinate aircraft reporting and radar to
fighter ground control was reached at a stormy conference in
Russia in the early stages of the campaign. MOELDERS and
GALLAND insisted that the only way to improve fighter
interception and cut down losses was to introduce satisfactory
ground control.

Research, Industry and Intrigue.
69. General MARTINI had a constant struggle to obtain the
technical improvements necessary for carrying on the high
frequency war. Except for a period of less than a year, during
which he was given special responsibilities by GOERING,
General MARTINI had no authority to make demands either from
the scientists or from the industrialists.
70. Until 1937 he and his subordinates had been allowed to
keep in close contact with the wireless industry, and to state
their requirements, but merely for information. After that
time Feldmarschall MILCH strictly forbade these contacts, and
ordered that requests and enquiries should be made by the
signals organisation through the Technisches Amt, of which he
was head. Feldmarschall MILCH knew just as little about high
frequency matters as GOERING.
71. MILCH issued his veto during a scandal in 1937 over the
sale of the FUGe.7 to Switzerland, in connection with which a
number of prominent scientists at Telefunken were arrested.
P/W had the feeling that the scandal was worked up to prevent
free collaboration between industry and the services, and to
place the big firms under the supervision of the Technisches
Amt.
72. Relations between MARTINI and MILCH were strained for
years, even if the two men were outwardly polite to each
other. MILCH was a great opponent of the General Staff, and
particularly of the Tactical Führungsstab. He attempted to
have the whole signals organisation placed under his command,
but MARTINI resisted this strongly.
73. Thwarted in his empire-building, MILCH carried on an
underground war against the signals organisation. On one
occasion, in the presence of MARTINI, he said to GOERING: "It
is a great crime that this signals organisation has been set
up!" MILCH tried to prevent Luftwaffe officers from working
in the Technisches Amt, and made liaison with MARTINI
extremely difficult. For a time MARTINI had a representative
at the Technisches Amt but he requested to be posted back to
the signals organisation, saying that it had room only for
engineers and not for officers.
74. MARTINI had engineers in his Experimental Regiment, the
L.N. Versuchsregiment at Koethen, working together with the
officers, but the engineers in the Technisches Amt refused to
co-operate with them. When the Versuchsregiment brought out
something new and stated its requirements, the Technisches Amt
engineers said that their work was all wrong.
75. Even during the time that UDET was head of the
Technisches Amt, MILCH in P/W’s opinion, really held the reins
because of his position as GOERING's representative.
76. Feldmarschall MILCH made a point of co-operating with the
signals organisation from the summer of 1941 for about nine
months, during which MARTINI had GOERING's backing. Because of
MILCH's opposition, MARTINI was still given no authority over
the scientists or the industrialists, but he was given special
powers to hold conferences with them, and with representatives
of the Technisches Amt.
77. He had GOERING's authority to discuss his requirements in
the utmost detail. When agreement had been reached on which
developments could be carried out by the industry, the General
had to make written requests to the Technisches Amt to put
through the required orders. Thanks to GOERING's backing,
MARTINI was able to force the Technisches Amt to place these
orders.

Role of the Versuchsregiment.
78. The Versuchsregiment had the task of conducting
experiments with signals apparatus, and stating the technical
or tactical requirements of the Luftwaffe with regard to it.
Their reports went to the Technisches Amt. When the apparatus
was delivered to the signals organisations the
Versuchsregiment carried out operational tests with it and
often made improvements.
79. The Versuchsregiment Koethen acted as a fillip to the
wireless industry, sometimes producing new apparatus which the
industrialists were unable to manufacture.
80. For example, the height measuring attachments on the Freya
were built and produced by Koethen. Whenever work of this
nature was handed over to Koethen, MARTINI had to obtain the
sanction of the Technisches Amt. Despite the rivalry with the
Versuchsregiment, this sanction would be given. Feldmarschall
MILCH once or twice indicated that Koethen should be directly
subordinated to him, but never pursued the matter.
81. General MARTINI described Dr. KÜNHOLD, the Technical
Chief of the Versuchsregiment, as exceptionally able and at
the same time very modest scientist. He was responsible for
all the technical work done at Koethen. Oberst LÖWE,
Kommandeur of the Regiment, was responsible for administration
and discipline. He was also a good technician. He had formerly
been a Captain in the Signals section of the Landes Polizei
and had been taken into the Luftwaffe signals organisation in
1934.
82. The work of the Versuchsregiment at Koethen embraced all
branches of the signals organisation; its work on radar was in
practice restricted to ground apparatus.
83. The experimental station at Werneuchen restricted its
research to radar and concentrated on airborne apparatus.
Whereas Koethen, under the signals organisation, trained the
experimental detachments which were incorporated in the
signals regiments, Werneuchen was restricted to engineers and
was subordinated to the Technisches Amt.
84. Oberstleutnant HENTZ, at the end of the war head of
General MARTINI's Radar Section, the VI Abteilung, was
formerly Kommandeur of Werneuchen responsible for its growth.
85. Co-operation between Werneuchen and the signals
organisation was always better than that of the Technisches
Ant itself with the signals organisation.
Industry's need of Technicians.
86. At the end of 1941, it became obvious that the wireless
industry did not have a sufficient number of technicians to
carry out the requirements of the signals organisation.
87. Realising the danger of defeat in the high frequency war,
MARTINI offered the industry up to 15,000 technicians from his
Signals Regiment. He started by having 7000 to 8000 men
transferred to industry, and then persuaded GOERING to
transfer back to the industry and research organisations about
15,000 technicians from both the Army and Luftwaffe.
88. While the transfers were being carried out, the manpower
crisis occurred on the Russian front and the process was
reversed. Thus the best experienced technicians were being
sent from industry to the Russian front, while less capable
men were coming home and required at least a year to be
trained.

Countering of Allied Countermeasures.
89. The very nature of the high frequency war with
countermeasures, measures to overcome countermeasures and
constant changes in the apparatus, led to demands from the
wireless industry which it could not meet. Thus the
Versuchsregiment was frequently called upon by MARTINI to make
the alterations itself.
90. For instance, when Freyas were manufactured with only one
wavelength, MARTINI told the industrialists that it would be
useless without a wave band. The industrialists replied that
such a change would be colossal work which would require a
very long time. "At any rate", MARTINI interposed, "bring out
the next series of Freyas with two wavelengths, the one after
with three, and gradually get a reasonable frequency band".
The industrialists made objections, saying that the work was
too fiddling.
91. MARTINI then ordered the Versuchsregiment to make the
required modifications in the Freyas. Thus, despite British
jamming from high-powered transmitters, the Versuchsregiment
modified a sufficient number of Freyas for some to operate
without being jammed.
92. Gradually all the Freyas were modified at Koethen under
the covername "Voll-Wismar" and the wireless industry finally
produced Freyas with an adequate frequency band.
93. Similar difficulties were experienced with FuG.16. The
signals organisation asked the Technisches Amt for the
apparatus to be constructed with 100 two-way channels, but
through a misunderstanding it was produced with 100 one-way
channels.
94. In the ensuing discussions, the industrialists considered
that they would not be able to produce the apparatus with the
required frequency band for about two years.

FuG.25 and 25A.
95. The failure to organise the mass production of the German
I.F.F., the FuG.25A, at an early date was attributed by the
General to the weakness of his position in relation to the
Technisches Amt. He was first shown the apparatus, which had
been constructed by Dr. SCHULTHES, in September or October
1939. He was delighted with it and requested the production of
two or three thousand.
96. These unfortunately were not produced, the General said,
because too many people had a say in the matter. "Shortly
afterwards a high official at the Technisches Amt told me
quite by chance that 30,000 FuG.25 were already in production.
That was terrible; it was my greatest worry. But
Reichsmarschall GOERING said to me "It is the easiest problem
of all and you haven't even solved that for me!"
Switching on of I.F.F.
97. The General had heard the explanation from British bomber
pilots that they kept their I.F.F. switched on to dowse
searchlights, but he did not believe it.
98. He thought that there must have been some important
reason this procedure which allowed the Germans to pick up the
approach of R.A.F. bombers. He asked whether it was maintained
with the object of eventually being of use to night fighter
escort aircraft. He pointed out that it was of exceedingly
great value to the Germans.

The Panorama Apparatus.
99. About September 1942, somebody, whose name MARTINI never
discovered, told GOERING that the signals organisation had
neglected to develop the Panorama search apparatus. GOERING in
a fit of temper told MARTINI that he had sabotaged the
Panorama apparatus and MARTINI retorted sharply. That same day
GOERING appointed Oberst KNEEMEYER as his Wireless and
Navigation Officer, and put an end to MARTINI’s special
functions in high frequency developments.
100. MARTINI continued to hold conferences with the
scientists and industrialists on behalf of the Chief of the
General Staff, but without GOERING’s authority he laboured
under great difficulties.
101. The production of a German Panorama apparatus was
delayed largely because at the beginning of the war tests were
unsuccessful, and afterwards the wireless industry neglected
it to try and satisfy other demands regarded as more urgent.
The first Panorama, which was put up to the West of Berlin,
could not be made to work and its development was shelved.
102. At the beginning of 1943, General MARTINI insisted that
he should be shown what the apparatus was worth. He was told
that the apparatus, which worked on one of the Freya
frequencies, had not yet been perfected. He sent two members
of his staff to try and overcome the technical difficulties
and three months later he was asked to inspect the apparatus
as it was at last working. He spent two hours looking at it,
but the demonstration failed.
103. A second prototype, which worked on decimetre waves, was
burnt out just after being completed.
Centimetre Wave Research.
104. The failure to develop radar on centimetre waves was
due, General MARTINI said, partly to Feldmarschall MILCH’s
lack of understanding of the problem, and partly because the
wireless industry could not cope. He himself had demanded in
1937 that research should be carried out on centimetre waves.
105. Staatsrat ESAU made experiments with ultra-short waves
at first with a milliwatt, which he later increased to a watt.
The scientist said that it was not his business, but that of
the industrialists to continue the work with higher power. The
industry, however, had too many other orders on hand, and
Feldmarschall MILCH, who could have put the research in the
hands of the Technische Amt, did not realise the implications
of the high frequency war.
106. In the summer of 1942, GOERING suddenly decided to
replace Dr. ESAU by Dr. PLENDL, whom he promoted to the rank
of Oberst Ingenieur, saying: "I appoint you chief of all high
frequency research in Germany". Dr. ESAU complained to General
MARTINI of being cold shouldered, but the General had not even
been informed of GOERING's decision beforehand.
107. General MARTINI made about 60 closely inter-connected
requests for research on high frequency matters to Dr. PLENDL.
He said that PLENDL's work as Chief of high frequency
investigations was somewhat disappointing, and criticised him
for spending too much time on organising, to the neglect of
research. He did not put the same energy into this work as he
had done in the development of the "X" and "Y" systems.
However, the General did not agree with those critics who
accused Dr. PLENDL of combatting the protagonists of the Egon
system.
108. In 1944 GOERING became dissatisfied with PLENDL, and
reinstated ESAU in his place. The old collaboration between
ESAU and MARTINI was then resumed.

The Egon System.
109. Dr. SCHULTHES, who first worked with GEMA for the Navy
and later with Siemens, had reported early on that the Egon
system promised great possibilities. At one of the General's
conferences in 1941, he said that exact location up to 350
kilometres could be attained with Egon, but could not give a
date for the perfection of the system. Nevertheless those
scientists who were opposed to Dr. PLENDL advocated the
immediate scrapping of the Benito fighter control system and
the introduction of Egon.
110. MARTINI intervened, stating: "The problem is not so
simple. We have built up the whole organisation for the Benito
system which has definite advantages; it can be used not only
for bombers but for fighters with very good results. We must
develop Egon with all possible speed, but before it is ready
to be used operationally it would be madness to do away with
Benito. We must have both systems operating at the same time".
111. In General MARTINI's view, time has justified his point
of view. The Benito system had proved itself thoroughly
efficient for fighter control, and in the later stages of the
war those controllers who used both systems were glad to check
up one on the other. With the small fighter force to which the
Luftwaffe was reduced, a small error in ground control was
fatal.

Capture of the British "Gee" Apparatus.
112. GOERING, who was in the habit of cursing the signals
organisation, was particularly vehement when he heard that a
British bomber had been captured with a fine apparatus on
board which was an improvement on anything brought out in
Germany. This was the "Gee" apparatus which the Germans named
Hyperbel.
113. General MARTINI said that he learned a long time
afterwards that the firm of Telefunken had actually worked out
a similar system to "Gee" on long waves in 1939. Telefunken
which had given the apparatus the cover name "Ingolstadt", had
proposed developing it, but the Technisches Amt had turned it
down because of an order previously issued forbidding work on
any developments which could not be completed by the end of
1940.
114. The "Gee" apparatus was handed over to Koethen for
examination and copies. The reason why Gee" was not jammed
earlier, the General thought, was because of the German lack
of ultra-short wave transmitters. It required a good nine
months to construct apparatus, once the prototype had been
completed. For a time, he said, the Germans considered that
they were successful in jamming both "Gee" and "Oboe", but
when these systems were used by the Allies with many
wavelengths, the only answer was to build up a great system of
jamming throughout Germany. This system was never completed.
Jamming – The Feldberg Project.
115. The General recalled an attempt in 1945 to jam Allied
airborne radar which ended in disaster. The first new highpowered
German ground jamming plant, which was manufactured
with great difficulty because of Allied bombing attacks, was
finally all assembled inside a tower on the Feldberg with the
object of jamming all wavelengths from the one place.
116. The work was carried out by the Reichspost "just as it
were peacetime" without a thought to passible consequences of
bombing. No sooner had all the apparatus been completed than
the tower was destroyed by a fighter bomber attack. The case
was brought before a court-martial.

H2S Countermeasures.
117. The Germans were not successful in their ground
countermeasures against H2S, because they were unable to get
such apparatus as they had captured intact to work properly.
The apparatus was technically in order, but despite repeated
trials the navigators were unable to achieve results with it.
Results were finally with a F.W.200 which was fitted with both
the H2S and the "Berlin". When flying over the Mark
Brandenburg in the spring of 1944, the aircraft crashed for
some unknown reason.

"Berlin" for Night Fighting.
118. It would have taken a long time, the General said,
before "Berlin" could have been put into operational use for
bombing on the same lines as H2S for which it was originally
constructed. As the Germans were not carrying out bombing
raids it was no longer important. It was therefor proposed to
adapt the "Berlin" for night fighting, and as such it would
have been used operationally within a comparatively short
while.
119. The Germans had great difficulty towards the end of the
war in constructing airborne apparatus such as "Berlin" small
enough to fit into their aircraft. They had scarcely any fourengined
aircraft, and the Ju.88 was not roomy enough. In the
final stages the wireless industry had to concentrate on
apparatus sufficiently small to fit into the Me.262.

Me.262 Radar.
120. No Me.262 had flown operationally with radar, but a few
successful trial flights had been carried out, using Neptun
apparatus which was small to go into the aircraft without
being unwieldy.
121. The type used was the forward-looking Neptun. The test
aircraft crashed and the observer was killed, but the pilot
reported that good blips had been obtained.

Me.163.
122. No attempt had been made to operate the Me.163 with
ground control.

Kammhuber’s Night Fighter Belt.
123. Speaking of the development of German night fighter
defences, General MARTINI said that General KAMMHUBER did not
at first appreciate the value of radar. Before the latter had
taken over the night fighter defences, he had distinguished
himself as a good blind flying pilot, but he had no technical
knowledge of radar. For that reason he organised the wellknown
searchlight belt defending the western approaches to the
Reich.
124. About two and a half months after KAMMHUBER had begun to
work on the night fighter belt, MARTINI sent him six reporting
companies which were then equipped with Würzburgs, because
MARTINI considered that this would be the best way of
organising night fighter defences.
125. The reason why the night fighter defence sectors were
worked out in a perfect pattern was that KAMMHUBER, being a
keen organiser, considered that he would benefit by their
being all exactly alike.
126. Asked why KAMMHUBER did not organise his night fighter
belt to rely on Würzburgs from the outset, General MARTINI
said that he himself had not been consulted when the work
began. GOERING had ordered KAMMHUBER to organise night
fighting, without referring him to MARTINI. KAMMHUBER did not
even know what to do with the aircraft reporting companies
which MARTINI sent him; however, he studied the whole question
of high frequency with much vigour, and soon reorganised the
night fighter defences to depend on ground radar.
127. The reason why so many radars were put up on the
Kammhuber belt was that the Germans at that time were using
the old Würzburgs which could obtain satisfactory results only
up to a radius of 35 kilometres. When the Würzburg Riesen were
introduced, General KAMMHUBER kept the other Würzburgs for a
time so as to maintain the pattern of his organisation
throughout the night fighter belt.
128. KAMMHUBER preferred the Seeburg Tisch method of plotting
to the Freya-AN system, because he said that the former method
of control could be understood by all but the latter could be
managed successfully only by special gifted officers. MARTINI
was disappointed because he considered that there were enough
capable young officers in his organisation to have worked with
the Freya-AN.

The Removal of Kammhuber.
129. The General said that he did not know exactly why
KAMMHUBER was removed to Luftflotte 5. In his own words, taken
from shorthand notes during interrogation: "It was a sudden
decision of the Reichsmarschall and I imagine that he must
have reached it after one of the officers had told him
something or other. It happened during a big conference at
Deelen during which the Reichsmarschall attacked me sharply
because he was determined not to understand why I wanted to
maintain the visual and oral aircraft reporting system as well
as the radar organisation. I explained that it was important
to know what types of aircraft were approaching when there
were low-flying attacks. He would have nothing of it and was
in a very bad temper.
130. "The next day he took General KAMMHUBER aside, and then
came back saying that he was to be A.O.C.-in-C. of the
Luftflotte in Norway. Possibly the reason for this was that
the night fighters were not gaining so many victories.
Outwardly the new post meant a great promotion, for he was a
young officer, and as A.O.C.-in-C. he attained the rank of a
General-Feldmarschall.
131. "I did not ask him what he personally thought about it.
Perhaps he had expected to control all the fighter forces in
Germany, and to have become an A.O.C.-in-C. like that.
132. "The change took place at the time of the appointment of
a new General Staff. I was to have been thrown out also. They
wanted to divide up my work, and I had made it a hard and fast
rule that my organisation must not be split up, whatever
happened. I had to insist on this several times, and each time
said that if the organisation were split up, I should ask for
another post. Finally on that occasion too, it was decided
that I should.....
133. The Reichsmarschall did not understand the principles of
night fighting, but discussed them a great deal with General
KAMMHUBER just as he did with me. When I held a different
opinion, I told him so quite openly. For a long time he
listened to me, and then one day he refused to listen to me at
all. It was roughly the same with General KAMMHUBER. He too
used to state his opinion openly".

IV - SUCCESS OF WINDOW.
Not a Surprise.
134. The dropping of Window by Bomber Command over Hamburg in
the summer of 1943 did not come as a complete surprise to the
German signals organisation. For about a year engineers at the
Technisches Amt had studied the question. The scientists had a
suspicion of the danger to German defensive radar but said
nothing because they did not wish to bring them-selves into
disrepute.
135. Six months before the Hamburg raid their experiments had
proved conclusively what a menace the metal strips
represented. The information was passed to MARTINI, who handed
GOERING a two-page report on the subject, pointing out what a
terrible danger they might be. GOERING was so upset that he
ordered MARTINI to destroy the document at once, and take the
utmost precautions to prevent the enemy from learning of the
discovery.
136. "It was thus extremely difficult", the General said, "to
work out countermeasures because we dared not experiment with
the little beasts for fear of their being discovered. Had the
wind blown when we dropped the metal strips, people would have
picked then up, talked about them, and the secret would have
been betrayed".
137. When the Hamburg raid came there was great excitement
because the signals organisation had not discovered any
countermeasures. GOERING blamed MARTINI again, saying: "The
British have now gone and used the metal strips, so they have
surely got countermeasures against them and you haven't!"

Window Countermeasures.
138. A few days after the Hamburg raid, two scientists
independently worked out countermeasures to Window and the
result was the Würzlaus attachment to the Würzburg and the
Freyalaus attachment to the Freya. When considerable
quantities of Window were dropped, the Würzlaus was swamped,
however, but the Freyalaus still gave results. Finally a
combination of the two, the "K-Laus", was tried out but was
found difficult to handle.
139. The General admitted that no really satisfactory answer
to Window had been found, and doubted whether there could be
one if the strips were dropped in sufficient quantities and
places. The Flak batteries never succeeded in using their own
radar instruments when the Allied air force used sufficient
Window or Chaff, but the aircraft reporting system was at
least able to provide them with rough data on height end
direction.
140. With Koethen Grau apparatus they managed for some months
to get a rough picture despite Window. German night fighters
were on the whole not too much affected by Window and at first
it frequently even gave them a rough idea of where to find the
bomber stream. Their task was then complicated by the
countermeasures of 100 Group, R.A.F. Bomber Command, which
General MARTINI described as outstandingly good.
141. Explaining the lines on which the Germans developed
their radar defences, General MARTINI said that in order to
obtain as early a warning as possible. They built bigger and
bigger apparatus, as the range of the Allied bombers
increased. The Germans thus gradually increased their warning
range from 100 kilometres with the Freya to 300 kilometres
with the Wassermann, the Mammut and the Elefant. The danger of
jamming and bombing was fully realised but the Germans were
glad to have the latter types of apparatus when the British
introduced Window and airborne jamming,
142. Elefant proved particularly useful as it was not jammed
for a long time. Results with Klein-Heidelberg were also good
General MARTINI believed that the apparatus had been invented
by Oberpostrat SCHOLZ, who had the chief merit for jamming
British radar when the Scharnhorst and Gneisenau passed
through the Channel. The General attributed the success of
this operation to the fact that it was started with very
slight jamming which was gradually and almost imperceptibly
increased until it became effective.

Wilde Sau Night-Fighting.
143. The fact that the Germans began to develop Wilde Sau
free-lance night fighting at the very time that the R.A.F.
introduced Window was largely fortuitous. Oberst HERRMANN was
mainly responsible. He said that the night fighter had to take
risks in German Flak areas and shoot down bombers caught by
the searchlights or in the glow of the blazing target. He said
he was quite prepared to do free-lance night fighting of this
nature himself, and did so.
144. GOERING, seeing that far fewer bombers were being shot
down because of Window, encouraged the younger night fighters
to go up over the targets and fight.

V - SIGNALS INTELLIGENCE AND SIGNALS DEVELOPMENTS.
SIGNALS INTELLIGENCE.
Work of the Intercept Service.
145. The German Signals Intelligence Service (Luft
Aufklärungs Dienst) was under the operational command of
Oberstleutnant FRIEDRICH, who was subordinate to MARTINI
through Oberst MORGENSTERN; the officer responsible for
discipline and administration of the service was Generalmajor
KLEMME. Coverage of Allied signals was determined by the
Intelligence of the Luftflotten in which the signals units
operated.
146. GOERING himself was interested in the service and
occasionally gave personal orders for some particular activity
to be covered.
l47. Results from the German Signals Intelligence had,
according to General MARTINI, given high satisfaction to
everyone until the last phase of the war, when the service, no
longer able to cope with the enormous number of Allied raids
or to keep track of the continually changing basings of Allied
aircraft, also came in for its share of GOERING's displeasure.
148. Up to this point it had never failed to provide, from
the Battle of Britain onwards, a current and exact Order of
Battle of the British and later of U.S.A.A.F. formations,
including subordinations, the number of squadrons operating in
each sector, and their dispositions and strength.
149. Valuable information on Allied fighters was given by the
interpreters, who were sent up with reconnaissance crews
operating from Norwegian and Mediterranean bases. They were
briefed beforehand in the locations of Allied fighter units in
the operational area, and the frequencies on which the latter
were likely to work. The low number of suitable men available,
however, had confined their employment to reconnaissance
aircraft. The General thought they would have continued to be
valuable as long as air to air and ground communication
remained insecure.
150. The Germans were able to recognise Allied preparations
for taking off, not so much through the pilots' talk as by
observation of small details in point to point traffic. The
slightest carelessness in procedure between two ground
stations, for instance, might suffice to reveal which networks
were active. Then, even though the traffic itself remained
unbroken, time and time again it became possible to draw
definite conclusions concerning the operations involved by the
comparison of traffics occurring in similar form.
151. The General admitted that sometimes the German intercept
service was tricked by British spoof traffic.
152. The very high standard of R/T discipline shown by
British pilots was held up by General MARTINI as a model for
German pilots, who, as a result of the example began to show
marked improvement in the later stages. He considered American
pilots to be about the equal of the German pilots in this
respect.

Employment of Signal Aircraft.
153. General MARTINI thought that experiments with Signals
Ju.52’s had begun in the Spanish war, but in any case
exercises with them shortly afterwards had proved their worth,
and they were used with success in considerable numbers in the
Polish Campaign.
154. Later on, with fighter units being constantly switched
from one area to another out of range of their home stations,
the signals Ju.52's were used to pass information from
Aircraft Reporting Station and ground radar to airborne
fighter formations.
155. As the scale of Allied attacks increased, it became
impossible to protect these signals aircraft on the airfields.
Their signals equipment was therefor made portable, taken out
on arrival at the airfield at which it was desired to operate,
and set up some distance away.
156. Allied bombing was thus responsible for the abolishing
of the signals aircraft, which was used in the later stages of
the war as a transport aircraft.

Liaison with German Navy.
158. All intercepted signals that concerned shipping were
passed immediately to the German Navy, who controlled the
costal observation posts. In general, liaison with the German
Navy in signals matters was very close indeed, key personnel
of both services and the Army often working together on the
same problems.

High Grade Cyphers.
159. The General did not think that Allied high grad Cyphers
had ever been broken, although since he was only concerned
with what came cut he could not speak with certainty. Allied
Cyphers in general were very secure.
160. Prior to the North African Campaign the Germans
themselves introduced the "Sägefisch" for communication over
great distances in the event of cable being rendered
unserviceable.
161. "Sägefisch" comprised a short-wave transmitter operating
in conjunction with an automatic cyphering Machine; it was
efficient only over distances of 250 miles or more. Messages
were typed into the machine in clear, automatically encyphered
and then transmitted. At the other end they were automatically
received, decyphered and typed out by the machine also in
clear, the entire operation taking only a few minutes.
162. Continual watch had been kept by the Germans on their
Sägefisch traffic, and whenever possibilities of the Allies
breaking down the cypher were observed, countermeasures were
immediately taken to render it more secure.

Defensive Measures.
163. Towards the end of the war, with the overwhelming
superiority of the Allied air forces, special efforts were
made to obtain the maximum efficiency from the German
Intercept Service, which was accordingly brought into much
closer co-operation with the Aircraft Reporting Service,
employing visual and radar means for aircraft detection.
164. Radar stations and intercept stations finally worked
together, both at Divisional and Sector Battle H.Q.'s. By
comparison of the intelligence produced by both services, it
was possible to obtain a more accurate picture of the air
situation. In this connection, the General said that Allied
bomber formations could be D/F's to within 1° of accuracy.
165. To ensure that German signals traffic could not help an
eventual enemy to D/F German airfields, General MARTINI laid
it down from the outset that transmitters must not be situated
in their vicinity. Throughout Germany, therefore, the wireless
transmitters were built at least 10 kilometres away from the
airfields. One transmitter station was usually built to serve
several airfields. To maintain land communications during
bombing attacks the decimetre wave point-to-point system,
Richtverbindung, for telephonic and/or telegraphic
communications was extensively developed.
166. In Italy, Allied bombing frequently made it impossible
for the Germans to move along the roads, and telegraphic
communications were wrecked. The Luftwaffe, however, was able
to help the Army out with its Richtverbindungen.

Point-to-Point Communication.
167. The General said that a number of conversations on
Richtverbindungen were held which should not have taken place,
since this method of communications was not secure.
168. Another difficulty with the Richtverbindung system was
that it could be seriously jammed. He believed that the
jamming which actually took place was by chance, and that it
came from airborne transmitters intended to jam the German
ground radars. He even considered organising a raid warning
system on the basis of this jamming.

Spoof before D-Day.
169. Before D-Day the Germans were tricked by a spoof
operation which gave them the impression that a big force was
making for Fécamp.
170. Although many aircraft reporting radars along the coast
had been put out of action by Allied bombing, the General
claimed that there were still sufficient left to maintain the
service. (He said that he was not responsible for the Naval
Radar Service). •
171. During the last few days before the invasion, the radar
operators were often misled to report that something was
coming when nothing was there at all. This was partly due to
the atmosphere, and the radar operators were accordingly
warned to caution when reporting.
172. As a considerable number of jamming transmitters on the
French coast had been destroyed by Allied attacks, the Germans
had to achieve results with mobile ones which were to jam
ground-to-air R/T. They were never used, having possibly been
destroyed on the way to the coast or on their arrival.

SIGNALS DEVELOPMENT.
Allied Bombing.
173. The signals organisation suffered most through the
Allied bombing of wireless valve factories; on the other hand
the General did not think that decisive results could have
been achieved, had the Allies made a concerted campaign
exclusively against the valve industry.
174. The Germans started dispersing stocks after Telefunken
and Lorenz had been severely damaged. A marked shortage of
valves resulted, but according to the General the situation
was never critical. The General admitted, however, that during
the Mediterranean campaign, for a time fighter aircraft were
delivered to Sicily without wireless apparatus.
Low Quality of Radar Operators.
175. It was mentioned to General MARTINI that earlier in the
war, when the Würzburg was captured on the French coast at
Bruneval, the prisoners who were taken with the apparatus were
found to have remarkably little technical knowledge.
176. The General ascribed this to the crisis in manpower
among wireless technicians, which forced him to use unskilled
men and later women as radar assistants.
177. Wireless technicians had to be trained within the
signals organisation, because before the war there were no
radio amateurs as in Britain and the United States. The
activities of all amateurs had been suppressed in Germany "at
the time of the Communist danger".

Failure of HS.293.
176. Lack of success with the Hs.293 radio-controlled glider
bomb was attributed by the General largely to two factors.
Firstly, the Technisches Amt, which was responsible for its
development and production, kept the weapon entirely for
itself. Only when it was realised that there were not enough
frequencies on the radio control of the bomb to make it immune
from jamming, did the Technisches Amt feel obliged to bring
the signals organisation into the picture. General MARTINI
insisted on a number of alterations, but the Hs.293 was
brought out before the radio control had been perfected to
make it free from jamming.
179. Secondly, the Germans had not sufficient numbers of
suitable aircraft from which the bomb could be operated. The
Do.217 with which it was mainly employed was, moreover,
extremely limited in range.
180. The high vulnerability of the Hs.293 to jamming was
accepted by the Germans, who decided that it had best be used
in a heavy surprise attack in an area where immediate
observation by the Allies would be difficult. Norway was
considered to offer best chances of success, and it was
therefore a very unpleasant surprise to the General to learn
that the bomb had been used in the Mediterranean theatre
shortly afterwards.
181. Nevertheless, to render Allied countermeasures as
difficult as possible and in order to camouflage tuning, radio
stations were set up whenever the bombs were being used, and
aircraft were employed with the bombers to transmit on other
wavelengths while the bombs were being armed.
182. In spite of these precautions the General thought that
the Allies might have succeeded in jamming the bomb, owing to
the extreme simplicity of the wireless control.
183. Radio-controlled bombs had been conceived solely as an
anti-shipping weapon, the HS.293 against large transport, the
FX against battleships and armoured vessels of all sorts. They
were afterwards relegated to uses for which they were never
intended - against bridges and other land targets.

Collaboration with Japan.
184. The extent to which the Germans gave their secrets to
the Japanese was not known by the General. He said that early
in 1945 HITLER ordered that all German technical secrets of
short and medium term value should be given to the Japanese.
185. He said that no members of the signals organisation had
left for Japan apart from those who were presumably in the Uboat
which was intercepted by the U.S. Navy in the Atlantic.
186. From a visit to Germany paid by a delegation of Japanese
officers. General MARTINI gained the impression that they were
behind-hand in radar. A Japanese told him that they had
apparatus with centimetre waves, but he could not remember the
details. He regarded the Jagi aerial as very good, but did not
know whether or not the Technisches Amt had received it from
Japan. He was sure that the Japanese had received at least
documents and photographs of German ground radar.

A.D.I.(K)&
U.S. Air Interrogation. S.D. Felkin
21st June 1945. Group Captain"

[Bruce Dennis]

"SECRET A. D. I. (K) Report No. 393/1945
THE FOLLOWING INFORMATION HAS BEEN OBTAINED FROM P/W AS THE
STATEMENTS HAVE NOT AS YET BEEN VERIFIED, NO MENTION OF THEM
SHOULD BE MADE IN INTELLIGENCE SUMMARIES OF COMMANDS OR LOWER FORMATIONS, NOR SHOULD THEY BE ACCEPTED UNTIL COMMENTED ON AIR MINISTRY INTELLIGENCE SUMMARIES OR SPECIAL COMMUNICATIONS.

G.A.F. INTELLIGENCE IN THE WAR.

Abteilung Ic (Chief of Intelligence).
1. The present report is the first of a series of three dealing with
some aspects of G.A.F. Intelligence during the War and in the series of
European incidents which preceded it. Whilst this report covers the
vicissitudes of the two Chiefs of Intelligence during the major part of
the War, Generalleutnant Josef ("Beppo") SCHMID and Oberst WODARG, the second and third reports will deal respectively with details of sources
of intelligence and their value to the Luftwaffe Operations Staff, and
with the working of Intelligence during the main incidents preceding the
War and in the main campaigns of the War Itself.
2. The information has been supplied by Generalleutnant SCHMID, the
Chef Ic from 1938 to 1942, Oberst WODARG, the Chef Ic from 1942 until
February 1945 and Oberstleutnant KIEMITZ, who worked under both SCHMID and WODARG and finally took over the latter's post. Some additional information was supplied by Hauptmann ZETZSCHE, chief of one of the Groups in the Ic department of Foreign Air Forces West and from
Oberstleutnant OHLETZ who, from January 1941 until March 1943, was
Ic of Luftflotte 6 on the Russian front.
3. The main impression gained from these interrogations is one of two
distinct phases in the fortunes of G.A.F. Intelligence, each the direct
result of the War situation at the time. These two phases fall roughly
into the periods of office of "Beppo" SCHMID and Oberst WODARG.
4. The handling of Ic by SCHMID for the furtherance of personal ends
and as an obliging and gratulatory adjunct to the G.A.F. General Staff
could find no impediment in the rising tide of German success. With the
reversal of fortunes and the ever-widening gap between the wishful
thinking or the General Staff and insistent reality at the fronts,
however, the broad and easy path of SCHMID became a tightrope from which he inevitably fell.
5. It is noteworthy that SCHMID, the close friend of GOERING, departed
to the command of Jagdkorps I with undiminished prestige, whilst WODARG, eclipsed by the glow of a former spurious glory, was left to struggle in evil times to obtain recognition of an unpleasant war situation. At times he was forced to the employment of amazing expedients in order to achieve this end. Since the acceptance of defeat could find no place in
Nazi philosophy it was never possible for the German Intelligence, which
had foreseen defeat as early as 1943, to achieve the prestige,
facilities and effectiveness enjoyed by its Allied counterpart.

THE FIRST CHEF IC - 1938 to 1942.
6. The 5th Abteilung was established as part of the G.A.F. General
Staff on first January 1938 and was to collect information on foreign
air forces and to build up target data for appreciation in air warfare.
The new department was to combine and systematise functions previously
the responsibility of a target data unit and of R.L.M. departments of
foreign air forces.
7. Those two organisations were already known respectively as Gruppe
II of the first Abteilung and the 5th Abteilung, and were manned by
civilians and reserve officers who had large quantities of information
from the foreign press and literature at their disposal, but worked with
no clearly defined aims; their main policy seemed to be deliberate
exaggeration of the strength of foreign countries it order to justify
German armament.
8. An appreciation by Generalleutnant SCHMID of the achievements of
these two organisations up to January 1938 will be found in Appendix I
to this report.
9. The new 5th Abteilung was to be under the command of
Generalleutnant, - then Major, - SCHMID, who since 1935 had been
employed in a ministerial capacity and had no knowledge of foreign
languages. He had, however, been recommended to GOERING by
Oberstleutnant JESCHONNEK, at that time Chief of the 1st Abteilung of
the General Staff.
10. The first task which SCHMID set himself was to replace his staff by
younger and more suitably qualified officers, although these were
difficult to obtain. The organisation of the 5th Abteilung, or
department Ic of the Ops. Staff as it now became, is shown in Appendix
II to this report. After the dismissal of SCHMID in 1944 the department
was reorganised by Oberst WODARG to the form in which it remained until
the closing stages of the war. This aspect is discussed later in this
report and the new organisation appears in Appendix IV.
11. The main departments of SCHMID’s new organisation were set up as a
first echelon at the Wildpark headquarters, and other departments as a
second echelon at the R.L.M. in Berlin. For 21/2 years SCHMID and his
staff lived and worked in the command train which was the "Robinson"
headquarters.
12. By the outbreak of war intelligence departments had also been set
up in the subordinate commands of the G.A.F., but choice and training of
staffs were far from satisfactory, and it was not until 1942 that Ic
(Intelligence) officers were appointed down to Geschwader and Gruppe
levels. Even then the type of officers chosen reflected a lack of
appreciation of the needs of Intelligence.
13. According to Oberstleutnant OHLETZ, the entire Ic service suffered
from lack of experience when the war broke out, since the apparatus to
meet the demands of war was not brought into being, until that time;
from the technical point of view, however, Intelligence had played its
part well up to that time, as, for instance, in that the target indices
available at the outset were good, as were the political and
geographical studies produced.
14. In spite of SCHMID's efforts to introduce younger men into
Intelligence at the time when he took office, his specialist staff was
still mainly composed of older reserve officers, the majority of whom
were lacking in both physical and mental agility. His officers were
blindly devoted to him and appeared uncritical of the course he gave
them to pursue.
15. Actually there was much disagreement in the G.A.F. concerning the
personality of SCHMID. His self-confidence was enormous and his enmity
was feared. By virtue of his double office as Chef Ic and GOERING’s
personal General Staff Officer, he exerted an influence over GOERING
outweighing even that of JESCHONNEK when the latter was Chief of Staff.
The strong tension later existing between SCHMID and JESCHONNEK was
openly discussed. It was also accepted that SCHMID would not tolerate
any officer about him who could become potentially dangerous to his
position.
16. The composition of his staff certainly appeared to bear out this
conviction. By dint bribery, a persuasive tongue and his proverbial
conviviality - was a heavy drinker – he had created about himself a
circle of officers who were completely under his thumb.
17. It is only in the light of this state of affairs that the
discrepancies between the information from intelligence formations at
the front and its dissemination by the Chef Ic to be discussed later in
this series of reports can, to some extent, be understood.

SOURCES OF INTELLIGENCES.
18. It was impossible for the 5th Abteilung to achieve the ideal
solution for the collection of intelligence, namely, the subordination
to it of all agencies concerned with the procuring of information.
SCHMID’s suggestion to set up an inter-service department of O.K.W,
which would build up a complete picture of the military, naval, and
industrial potentialities of the enemy met with no more success. The
result was that each service produced a partial appreciation from
available sources, whilst the S.S. maintained a separate agent and
foreign service.
19. The 5th Abteilung sought to administer its own press and attaché
service, the technical study of foreign aircraft and the interrogation
of prisoners. It also claimed that it should be the channel for liaison
with the Foreign Office and the Ministry of Propaganda, should have the
right to control sales of German aircraft abroad, and finally that it
should have the sole responsibility for a day-to-day appreciation of the
situation in war. From SCHMID's point of view, however, few of these
matters were arranged satisfactorily.
20. In the spring of 1939 he was able to obtain control of the R.L.M.
press department following upon certain blunders in the censorship, and
in the few months remaining before the War introduced a tighter
discipline.
21. The aims of the press department were to glean information from the
foreign press as well as to conduct propaganda for the G.A.F. in press
articles, pictures and films whilst maintaining a control of the
security aspect and, after outbreak of War, to organise the G.A.F. press
publicity units. The wartime organisation was never clearly defined,
however, being complicated by the rival intervention of the Propaganda
Ministry.
22. Liaison with the Propaganda Ministry produced good results only in
the form of films and other comforts for the troops, but in the
favourable periods of the War the difficulties of propaganda and
censorship were not important. Later, however, WODARG found himself
blamed by GOERING or the Chief of Staff for errors in publication over
which it was impossible to keep a control – a situation which led to
much personal friction.
23. The provision of foreign newspapers was in the hands of the
Sicherheitsdienst and the supply of daily papers for intelligence
purposes was therefore irregular, although periodicals could be obtained
without much difficulty. Liaison with foreign scientific institutes was
forbidden and could only be conducted through the Abwehr.
24. The G.A.F. Attaché Service abroad was subordinate to the Chef Ic,
and was also responsible for securing the confidence of German-allied
and neutral air attachés in Germany. Although the Attaché Service was
regarded as a valuable potential source of information, its
subordination to the 5th Abteilung was not brought about until the
spring of 1939.
25. Its contribution to the information on foreign air forces was very
small both in peace and war. Before 1939, when the Attaché Service had
been subordinated to the central office at the R.L.M., its chief, Major
CRAMON, had refused to regard the obtaining of information as part of
his task, added to which GOERING's attitude had always been to send illqualified officers abroad as air attachés.
26. The importance attached by the head of Ic to the Attaché Service
did not meet with official approval and the Attaché conferences held at
Berlin at which was expressed the dissatisfaction of Bulgaria, Rumania,
Hungary and Turkey with the lack of German support, were finally
forbidden on account of their political character.
27. The Foreign Office declined to pass on military or air information
via its officials, and only after outbreak of war was closer liaison
effected by setting up a representative (Ic/Pol) who, however, only
covered the rather restricted questions of violations of the frontier,
exchange of prisoners, free passage of ships and listening to enemy
radio.
28. Intelligence officers of all departments had at first been allowed
to listen to the enemy radio, but this was restricted in summer 1942 to
Ob.d.L. and the heads of the Luftflotten and a list had to be sent to
the Propaganda Ministry of all persons to whom this authority was
delegated.
29. SCHMID considered the Abwehr department to be the worst
functioning institution of O.K.W. and stated that whatever material was
supplied by it could not be appreciated at its true value because there
was no way of judging the reliability of the agents. The Abwehr was a
huge and expensive organization but, according to SCHMID, it was manned by the worst and most unsuitable officers in the services. It achieved very little in peace and only occasional chance results in war. At the beginning of the war it had undeserved larols thrust upon it by the
attention paid in enemy countries to the fifth column. SCHMID did not
find it surprising that the S.S. took over the whole organisation with
apparent ease.
30. At the outbreak of war the special photo-reconnaissance Staffel
formerly subordinated to the office of O.K.W. was put under the control
of the 5th Abteilung and became the Ob.d.L. Gruppe. SCHMID praised the
outstanding reconnaissance work of this unit in all theatres of war, as
well as pioneer technical achievements in high altitude flying. The main
sources of intelligence were, however, the wireless interception service
and the interrogation of prisoners of war although the latter did not
produce any outstanding results until towards the closing stages of
SCHMID's period of office.
31. The wireless interception service was developed in peace-time by
General MARTINI and was still controlled by him during the whole of the
war. SCHMID recognised the valuable nature of the work done by this
department, but depreciated the tendency of the Signals Staff to issue
independent appreciations which were necessarily incomplete and
unbalanced. In his opinion much more could have been achieved by its
subordination to an organisation with a wider horizon and more
penetrating aims. This deficiency became even more apparent to SCHMID
when later in the war he became the Chief of Jagdkorps I and was
concerned with defence of the Reich.
32. An appreciation by Generalleutnant SCHMID from memory, and unaided by documents, of Intelligence covered by the organisations mentioned above appears in Appendices III A to C of the present report.

DISSEMINATION OF INTELLIGENCE
33. In the early stages of the war the 5th Abteilung was responsible
for drawing up situation reports under the headings of air attacks, air
defence and the sea and land situation. These reports were based upon
those received twice daily from the fronts by the Ic Report Centre and
often had to correct hasty and exaggerated reports which had reached
GOERING through In (Operational channels). When Germany began to suffer reverses in the War the distribution of these Intelligence reports was
restricted and in the spring of 1942 GOERING forbad their publication
altogether.
34. Chef Ic had other tasks which were not purely concerned with the
G.A.F. direction in that he passed Intelligence to interested specialist
ministers and general staffs of German-allied countries whenever it
seemed necessary or opportune, being thereby drawn into conferences
outside the G.A.F.
35. At certain intervals reports were issued by Chef Ic containing a
survey of the position on individual fronts. There were, however, other
bodies which trespassed upon the functions of the 5th Abteilung or
overlapped in the issue of intelligence appreciations. UDET's technical
office under Oberst Ing. TSCHERSICH (GL/Rü) appeared to consider that
its task was to prove that all foreign equipment was inferior to German.
His reports on the excellence of German Intelligence, bombs, and weapons
were preferred by GOERING, and enjoyed great popularity in the period
after the French campaign. This organisation was finally linked up with
the Chef Ic in 1940 and was reorganised with good effect under Oberst
Ing. SCHWEPKE.
36. The head of the O.K.W. Wirtschaftsstab had announced at a
conference in the summer of 1939 that his task in War would include the
conduct of strategic air war-fare. This body did in fact issue reports
on the sensitivity of foreign countries to air attack. A Ic
Wirtschaftsstab was later formed under WODARG, but according to the
staff of Oberstleutnant KILLINGER of Dulag Luft the opportunity of
interrogation of Allied prisoners on industrial subjects was almost
completely neglected; the interrogators could never obtain the necessary
briefing or outside interest for such work.
37. An example of the worth of the Ic Wirtschaftsstab in January 1943
in the form of appreciation of British synthetic oil production and
Russian oil production has recently come to light in a captured document
now in the hands of A.D.I.(K) Document Section (List No.93).
38. In the opinions of KIENITZ, OHLETZ and ZETZSCHE the Ic Service
itself suffered from the fact that its Chief did not present with
sufficient obduracy a plain unvarnished picture of the situation which
was to be concluded from practical experience at the front, and from
indubitable facts photographic reconnaissance and captured material,
underlined by P/Ws’ statements, outside intelligence and above all by
evidence from the wireless interception service.
39. One result of this was that the total numbers of British bombers
engaged in night attacks on Germany was not believed, and when the Chief of Ic confirmed the accuracy of CHURCHIL's figure for the 1000-bomber raid on Cologne in May 1942, he laid himself open to charges of
defeatism and theorising. His reports acquired the reputation of
"Lügenmeldungen" (lies) among members of the Operations Staff, and the
Chief of Air Staff finally ordered that the Ic staff should be cut down
to lessen the output of unpleasant nonsense.
40. In another instance of this kind, which is described more fully in
the final report of this series, disagreement of Luftflotte 6's figures
of Russian strength became so acute that JESCHONNEK ordered an enquiry into the methods of appreciation by Oberstleutnant OHLETZ, the Chief Intelligence Officer of the Luftflotte.
41. The strength postulated by Chief Ic for the Russian Air Force was
but a fraction of the enemy strength actually encountered at the front
and so increasingly worthless did the appreciations become that at the
instance of von GREIM, OHLETZ refrained from handing them down to the
operational units in order that their faith in the Higher Command should
not be further shaken. There were days on which over 100 aircraft were
shot down in the area of Luftflotte 6 alone, whilst Chef Ic was
estimating the total Russian effort as 150 to 200 aircraft on the entire
Eastern front.
42. In order to cover his intelligence officers, von GREIM himself flew
immediately to headquarters to put the case personally. On his return he
informed OHLEZ that JESCHONNEK had recognised the accuracy of the
Luftflotte reports and wished the fact to be conveyed to him; he added
that Oberst SCHMID would not remain in office much longer.

DISMISSAL OF SCHMID
43. Matters were brought to a hold as far as SCHMID was concerned when
in August 1942 an Ic officer of the Attaché Gruppe, Oberstleutnant
SCHULZT-BOYSEF, was arrested by the Gestapo, in agreement with GOERING, on a charge of espionage for Russia. A number of other members of Ic were questioned and altogether at least 100 persons were arrested in Berlin in what became known as the "Rote Kapelle affair".
44. It was established that SCHULZT-BOYSEF, had had sources of
information in the G.A.F. Technical Office, in the Foreign Office and
the O.K.W. although he had not received secret information of any kind
from Ic. Nevertheless, SCHMID was reproached by GOERING and the Chief of Staff for having protected SCHULZE-BOYSEF in 1938 and at the beginning of the war against the suspicions of the Gestapo.
45. In October 1942 SCHMID was relieved of his post, officially because
of the Rote Kapelle affair; in the G.A.F., however, it was considered
that his departure was due to events at the front not having conformed
with his predictions.
46. After SCHMID, the task of taking up the reins of Ic was allotted to
Oberstleutnant KOEGL who, however, was not suited to his duties and
handed them over shortly afterwards to Major WODARG. KOEGL’s short
tenure had one good effect in that it brought Oberstleutnant KIENITZ
more into the picture. According to OHLUTZ that officer was a very
accurate worker, but unfortunately, although undeniably the most
valuable of the officers in responsible positions, did not possess the
particular gifts necessary to make a successful Chef Ic.

WODARG's TENURE OF OFFICE - 1942 to 1945
47. Major WODARG had been deputy head of Ic under Oberst SCHMID and he was also involved in the Rote Kapelle affair and was dismissed at the
same time on a charge of failing to maintain adequate supervision. He
was saved from further punishment only because it was maintained that
meticulous secrecy had been carried so far in the Gruppe Ost and the
Operations Staff that supervision by WODARG had been impossible.
However, 5 months after the dismissal of SCHMID, WODARG succeeded KOEGL as Head of Ic.
48. He took up his duties with remarkable energy and he soon rid
himself completely of the superannuated personal staff of Ic, apart from
a small number of experts, and introduced young and highly ambitious
General Staff officers. By this means he diffused considerably more
energy into the department. Oberstleutnant KIENITZ was available to
facilitate the smooth change-over from the SCHMID regime, and with his
complete mastery of the methods of the past provided a good liaison with
the new generation.
49. A table showing the Ic staff after its reorganisation by WODARG
appears in Appendix IV and may be compared with the organisation under
SCHMID given in Appendix II.
50. According to KIENITZ, WODARG undoubtedly brought the required ideas and breadth of vision to Intelligence. His methods of evaluating the
War situation were completely revolutionary and his appreciations were
built up on the basis of front Intelligence, being given out unvarnished
and untainted by the methods which had played such a big part with his
predecessor. For protection against attempts to oust him from the saddle
he relied on a very close relationship with the ministry of Dr. GOEBBELS
and the Reichssicherheits Hauptamt (security police headquarter).
51. His work was much hampered by his one outstanding peculiarity,
which stamped his department with a certain character. His mind was
imbued with a morbid distrust of the whole world and he suffered from a
form of spy mania which could almost be described as pathological. This
made life very unpleasant both for himself and for those about him. He
had his officers watched continually and he checked every possible
method and procedure with Amt IV of the Sicherheitsdienst in order to be
in a position to cope immediately with any possible threat to himself or
his department.
52. In his relations with GOERING Oberst WODARG was made to feel that
he was an imperfect substitute for Oberst SCHMID the founder and
architect of the Ic Service. WODARG never attended a Führer’s
conference, nor was he allowed in HITLER’s presence because of his
Jewish appearance - he had Jewish connections in both his own and his
wife's family. In the O.K.L. he was the least important personality of
the staff and he himself did not consider that he was the right man,
especially in view of his ill health, to have played an active part in
the shaping of policy and the raising of Ic from its subordinate role in
the councils of O.K.L.
53. In spite of the drive which WODARG brought to Ic and in spite of
his many ideas the work of Ic was doomed to failure in that it had to be
performed at a time when the G.A.F. was at its lowest ebb, when through
lack of air reconnaissance and liaison with Mi1itary Intelligence
services, the enemy dispositions were becoming increasingly difficult to
arrive at. Ides might burst from WODARG in an unfailing flow, but no
sooner did some new factor crop up than the situation grew out of hand
again. That the department functioned with any regularity at all WOGARD
felt was due to Oberstleutnant KIENITZ, who as WODARG’s permanent deputy provided the one stable focal point in the entire organisation.

INTERNAL INTRIGUE.
54. From the time of his own implication in the Russian spy affair,
WOGARD maintained more or less friendly relations with officials of the
S.D. in the Reichssicherheitsdienst Hauptamt, relations which were
fostered by the judicious distribution of delicacies from G.A.F. stores.
Apart from the confession that these occasional visits provided him with
an excuse vis-à-vis the O.K.L. Staff for leisure hours in Berlin or
otherwise unauthorised journeys, WODARG gave three examples of his
exploitation of these contacts.
55. He passed on as a precaution any reports on officers who seemed to
him to arouse suspicion, but often without any further action to be
taken as the investigating authorities were too overburdened. In return
the S.D. sometimes passed to Ic reports of corruption inside the G.A.F.
which were dealt with internally by the O.K.L. without BORMANN being
drawn into the matter.
56. After the bomb explosion in HITLER’s headquarter WODARG shortcircuited the S.D.'s investigations into the General Staffs by himself
undertaking to watch over O.K.L. by means of GOERING’s Forschungsamt.
This telephone eavesdropping was reduced to a farce since there was only
one possibility of listening-in on six exchanges with a daily average of
12-18,000 telephone conversations. Discreet personal warnings were
passed by WODARG to the Air Staff, and a few weeks later the control was
dropped after WODARG had reported to GOERING and so to HIMMLER that the task had been carried out with negative result.
57. In autumn 1944 the Sicherheitsdienst office at Frankfurt charged
Oberstleutnant KILLINGER and his interrogation officers with anglophile
tendencies, defeatism and transgression of service rules. The S.S.
demanded punishment of the offenders and subordination to the S.S. of
the prisoner of war interrogation centre, which WODARG interpreted as a
move by Amt IV of the R.S.H.A. to steal a march on Amt VI. WODARG claims the credit for having taken successful steps to get the matter settled by G.A.F. court martial instead of in the People’s Court.
58. Through his former activity as G.A.F. censor, he was on good
relations with Dr. GOEBBELS, about whom he records the admittedly quite
new point of view that he was personally in favour of coming to terms
with the Allies long before the catastrophic effects of Allied air
supremacy. He had a wholesome respect for Allied statesmen, and warned
against the error of underestimating the enemy. WODARG used his contacts in the Propaganda Ministry, the personnel of which was mainly G.A.F. officers, to play off one government clique against another and to
secure private information which he claims to have used to protect
O.K.L. against the S.S. - until the latter took over all the key
positions in the Propaganda Ministry.

OBERSTLEUTNANT KIENITZ
59. In February 1945 Oberstleutnant KIENITZ was put in charge of Ic,
although he was never appointed Chef Ic. After service as a
Gruppenkommandeur with J.G.3 in the early part of the war he held office
successively under SCHMID, KOEGL and WODARG, being responsible for Order of Battle first on the eastern front and later in the West. From
November 1944 onwards he was WODARG's deputy and right hand man.
60. After taking over from WODARG, KIENITZ very soon came to the
conclusion that the G.A.F. had become a purely ground support air force,
and he therefore directed all his efforts towards the determination of
Allied intentions first in the East, later in the West — as indicated by
the position of new airfields, ammunition and fuel dumps, unit
movements, etc. For this information he relied mainly on the W/T
listening service; the results of his findings he embodied in as air
situation report.

GERMAN INTELLIGENCE – CONCLUSIONS.
61. The mentality of the German rulers, who had risen to power in
internal political strife and were fanatical to the point of despising
the intelligence of the so-called "Intellektuellen", was such that they
were incapable of appreciating an intelligence service of their own
fashioning or of respecting the intelligence service of the enemy.
Otherwise according to WODARG, they would have avoided the War in the
first place, or having recognised the absolute superiority of the enemy,
would have concluded peace earlier - about the beginning of 1942.
62. The General Staff of the G.A.F., in common with the other branches
of the armed forces, was in WODARG's opinion too small and untrained to
assume effective leadership even if the Chief of Staff had recognised
the value of the intelligence service in general or appreciated its work
in detail. Since this recognition was lacking, Ic was inadequately
staffed in comparison with Ia, the operations department. Moreover, the
lack of co-ordination between the sources of information and Ic limited
considerably the latter's ability to draw up a complete intelligence
picture.
63. The activity of the General Staff and particularly the Ic
department was further crippled by HIMMLER's assumption of power over
the State and armed forces, and from spring 1944 onwards the General
Staff had to struggle for existence against the encroachments of the
S.S.
64. Hauptmann ZETZSCHE has summed up the main weaknesses of German
Intelligence during the War in the following main points:-
A) Within the State.
i) There was no hard and fast Ic organisation within the
Wehrmacht with boundaries clearly demarcated from those
of similar civil bodies.
ii) Wehrmachtführungsstab Ic did not co-ordinate the work of
the Heeres-, Marine- and Luftwaffenführungsstäbe Ic, but
was merely a distributing agency for the Ic reports of
the individual Wehrmacht components, exercising
practically no authority over them.
iii) The large number of intelligence organisations in Germany
without clearly defined tasks, including O.K.W./
Amtsgr.Ausland, R.S.H.A. (Mil.Amt), R.S.H.A. (Hauptamt
IV) and Reichsministerium Speer (1. Abtlg). (The
Propaganda Ministry and the Foreign Office also partly
covered the same territory).
iv) The lack of a Ministry of Economic Warfare. Military
Commands were obliged to cope with the problems without
expert knowledge or guidance, (e.g. in the Battle of
Britain). With so many independent intelligence
organisations and no centrally co-ordinated hand the
Germans consequently never saw the enemy picture as a
whole.
B) Within the G.A.F.
i) Again innumerable bodies working over the same ground as
G.A.F. Ops. Staff Ic, TLR Rü, Gen. Nafü, Waffengeneräle,
Forschungsamt, etc. These departments were not
responsible to Ic and on grounds of personal ambition
worked by and far for themselves. All this was due to the
lack of a “man of stature” as chef Ic (GOERING’s phrase).
ii) The not altogether happy organisation of G.A.F. Ops.
Staff Ic (Luftwesen, Ic/See, Ic/Bild).
iii) The subordination of Ic to Chief of G.A.F., whose
decisions were too often swayed by In considerations.
iv) Ic was kept as ill-informed on the subject of German
weapons, apparatus, etc. that it was incapable of
offering suggestions which would otherwise undoubtedly
have arisen from Ic knowledge of Allied material.
v) Ic's tactical suggestions were mainly ignored owing to
the jealousy of the Training Abteilung which again was in
no position to evaluate enemy information since in the
sphere of training too, there were many figures in the
pie (principally those of the Waffengeneräle and Forward
Commands).
vi) Ic was unable to have its wishes carried out by Forward
Commands. It could not order but only request.
vii) The poor quality of Ic personnel. Many officers who were
not wanted by other branches of the service found their
way into the various departments of Ic.
viii) Ic was considerably understaffed. Moreover, such staff
as it had was unevenly distributed in relation to the
tasks.
ix) There were no Ic officers with the flying units, so that
valuable lessons which might have been drawn from battle
experience were lost.
x) The lack of intelligence courses for officers
xi) The insufficient support of Ic in every sphere, e.g. no
aircraft, no cars, no money or additional comforts and
drinks (the latter for P/W interrogation centre,
Oberursel), insufficient communications with Oberursel.
65. Ironically, the sole organisation to recognise the worth of Ic was
the S.S. (since most personnel had connections with foreign countries
and were therefor already under suspicion). Hence the efforts of the
S.S. (by means of agents) to keep a watch on the entire Ic organisation
in Germany and finally even to take it over.

A.D.I.(K) and Walter A. Frank
U.S. Air Interrogation. for:- S.D. Felkin
Group Captain."

[Bruce Dennis]

"SECRET A.D.I.(K) Report No.525/1944
THE FOLLOWING INFORMATION HAS BEEN OBTAINED FROM P/W
AS THE STATEMENTS HAVE NOT AS YET BEEN VERIFIED, NO
MENTION OF THEM SHOULD BE MADE IN INTELLIGENCE
SUMMARIES OF COMMANDS OR LOWER FORMATIONS, NOR SHOULD
THEY BE ACCEPTED UNTIL COMMENTED ON AIR MINISTRY
INTELLIGENCE SUMMARIES OR SPECIAL COMMUNICATIONS.

FIGHTER DEFENCE OF GERMANY

CONTROL OF FIGHTERS BY THE "Y" PROCEDURE.
1. The Interrogation of G.A.F. fighter pilots in the past has
made it possible to form a picture of German tactics against
U.S.A.A.F. bomber formations from the point of view of fighter
interception force. Knowledge by P/W of the raid tracking
organisation on the ground, however, has up to the present
been lacking, and many gaps have remained in the picture,
particularly where the Fühlungshalter (shadowing aircraft) and
the "Y" controlled fighters are concerned.
2. Two G.A.F. Signals Officers, who had been directly
concerned with "Y" control sites - one man was a plotting
officer - have now described in some detail the method of
ground control at present being used in the operation of
fighter interception forces and of the shadowing aircraft;
their knowledge was chiefly confined to methods practised in
France, but they state that the same principles also apply to
operations in Germany.
3. Some of the information is of a semi-technical nature, and
the present report is therefore divided into two parts; the
first part concerns the operational aspect of fighter control,
and the second part deals with the equipment and method of
operation of the unit of control - the "Y" site.

I. CONTROL OF FIGHTER INTERCEPTION.
OPERATIONAL CONTROL.
4. In Allied attacks on Germany, the Jagd Division receives
and plots all Radar information on the movements of the bomber
formations, together with direct reports from the
Fühlungshalter aircraft shadowing those formations and the
plotting reports from the fighter "Y" control sites. It is
primarily on this information that the Divisional commentary
and the control of a whole interception action are based.
5. The sole medium for transmission of the Divisional
commentary is the "Y" site; the latter is connected by
landline to the Divisional plotting centre so that the
plotting of an operation is carried out at both those centres
simultaneously.
6. An interception can therefore be directed either from
Divisional Headquarters or from the "Y" site, but it is
normally the plotting officer at the "Y" site who puts out the
R/T commentary.
7. The area of control ("Führungsraum") of a "Y" site is
limited by the range of the transmitters used, and according
to P/W the average range may be taken as 250 to 300
kilometres; the Division therefore controls an operation over
its territory by making use of a chain of "Y" sites.
8. The area of R/T control of a "Y" site may be increased by
additional ground relay transmitters, known as "Brummer", so
that R/T communications with fighters can be continued outside
normal range. These stations and their operation are discussed
in Part II of this report.
9. The present P/W stated that the Central Operational
Headquarters ("Zentral Gefechtsstand"), situated in the Berlin
area, receives simultaneous information from each Divisional
plotting centre and makes its own plots on that basis; the
fighter commentary on the "Reichsjägerwelle" or such orders as
are put out on the broadcaster "Annemarie" emanate from that
centre, but according to the present P/W are only utilised by
fighter interception forces in case of failure of the
Divisional commentary, or the breaking up of an interception
formation.

"Y" CONTROL OF FIGHTERS.
General Principls.
10. The principles of "Y" fighter control, whereby the range
and bearing of friendly fighter are determined by a "Y" ground
station, are already well known.
11. In operations in Germany, the "Y" site, known as a
"Stellung", usually consists of five separate stations
("Stationen"), each of which comprises a transmitter hut and
mast, and a receiver pylon incorporating a D/F, and rangemeasuring
unit. All five stations are connected to a plotting
room situated on the site.
12. Each station of the site is allotted a separate W/T
channel, known as "Linie", consisting of a transmitter and a
receiver carrier frequency; thus a number of individual
aircraft can be controlled simultaneously within a given area.
13. In order to extend the control of a single aircraft, such
as a night-fighter, to that of a number of aircraft, such as a
day fighter interception force, it is only necessary to
include a "Y" controlled aircraft amongst the fighters of the
formation.
14. In this case the receivers of all aircraft in the
formation wi11 be tuned to the ground transmitter frequency to
receive R/T instructions from the plotting centre as well as
from the fighter formation leader.
15. In this manner up to five separate interception formations
can be controlled, each on a different frequency form a single
"Y" site. If necessary, all five formations can be brought
together to intercept a single bomber formation, or
alternatively, each of the five formations can be despatched
separately to meet the bombers or their fighter cover at
various points.
16. The ground transmitter carrier frequencies, known as the
"Gemeinschaftswelle", are distributed over the 40.4 to 42.3
mc/s. band at intervals of .05 mc/s. and the ground receiver
carrier frequencies, known as the "Messwelle", are distributed
over the 38.5 to 40.4 mc/s. band at the same intervals. A list
of such frequencies numbered 1 to 40, appeared in a recently
captured Signals Order (A.D.I.(K) 4.68/1944, paras.41-42).
17. In operation, the ground transmitter carrier frequency is
modulated by a continuous note of 300 or 3,000 cycles; the
receiver/transmitter in the "Y" aircraft (known in J.G.3 as
the "Lotse" aircraft) receives its modulation and
automatically re-transmits it on another frequency in the 38.4
to 40.4 mc/s. band; the aircraft transmitter frequency is
normally 1.9 mc/s. lower than the ground transmitter
frequency.
18. The re-transmission from the aircraft is picked up at the
"Y" station by the D/F receiver, by which the bearing of the
aircraft is than determined. The same transmission is also
received by the range-measuring unit, and the distance of the
aircraft from the station is determined by measuring the phase
difference of the modulation received.
19. The height of the aircraft under control is not measured
by the "Y" station, but is obtained over the R/T channel from
readings taken in the aircraft, thus all the data required for
the plotting of a controlled aircraft, viz. bearing, distance
and height, are obtained.
20. There are two methods of controlling aircraft formations
by means of the "Y" procedure, and these are illustrated
diagrammatically in Sketch I.
21. The first method, known as the "Begleiter", has now
dropped out of use, but is repeated here as a matter of
interest. By this method, the leading aircraft of a formation,
known as the "Führer" aircraft, also acted as the "Y"
aircraft, whilst the accompanying aircraft of the formation
were known as "Begleiter".
22. In the Führer aircraft the receiver was linked with the
transmitter and the receiver frequency was tuned to the ground
transmitter frequency, whilst the aircraft transmitter was set
to the frequency of the ground receiver.
23. In all other aircraft of the formation the receiver was
tuned to the transmitter frequency of the leader, and in none
of them was the receiver linked to the transmitter. The
formation was thus plotted solely by the position of the
Führer aircraft.
24. The Begleiter method has, according to P/W, now been
replaced by a newer method known as the "Gemeinschaftswelle",
in which the receivers of all aircraft of a fighter formation,
including that of the leader, are set to the ground
transmitter frequency ("Gemeinschaftswelle"). In this method
the aircraft is not the leader of the formation but he flies
as N°2 to the leader, with one or more similar aircraft as
reserves.
25. Upon referring to the Sketch, it will be seen that the
formation leader's instructions are not heard directly by the
"Y" station; they are picked up by the receiver of the "Y"
aircraft (in this case on 41 mc/s.) and automatically retransmitted
(on 39.1 mc/s.) to the ground station.
26. On the other hand, should the pilot of the "Y" aircraft
wish to speak to his own formation leader, he must pass his
message to the ground station on 39.1, mc/s., and the plotting
officer will repeat the message on the Gemeinschaftswelle.
Transmission of Commentary.
27. A plotting officer on the "Y" site, or his counterpart on
the extended line to the Divisions, is provided with
headphones connected to the receiver of the range-measuring
unit, and with a microphone which is connected to the
transmitter.
28. By depressing a key he can link the microphone with the
ground transmitter and can impose R/T speech on the already
modulated carrier frequency which it sends out. It is not
necessary to discontinue the modulating note, so that D/F’ing
and range measuring can therefore proceed at the same time as
the commentary.
29. In practice, the fighter interception force is led by the
"Y" control officer as far as within sight of the bomber
formation, at which point R/T control ceases to allow the
formation leader to direct the combat, and is only taken up
after combat when the fighters have re-formed for a second
interception, and the "Y" aircraft has made fresh contact with
ground control. During this time, however, the ground station
continues to plot the formation through the "Y" aircraft.

Fühlungshalter Aircraft.
30. It will be remembered that when a U.S. bomber force is
reported to be entering German territory a special shadowing
aircraft, the Fühlungshalter, wi11 be sent to meet and follow
that force and report its movements and position.
31. The Fühlungshalter aircraft operates under the control of
the "Y" plotting officer in the manner described above. In the
opening stages of an operation, the Fühlungshalter is directed
to the penetrating formation on the basis of Radar plots, and
upon making contacts it takes up a position usually above and
to the rear of the enemy formation.
32. The Fühlungshalter then reports strength, type of
formation, direction, height and fighter cover of the
penetrating force. After the initial report, further
information is only sent in the event of major changes in the
composition or movements of the U.S. formations.
33. As soon as the Fühlungshalter has made contact with the
bomber formation, all R/T control by the "Y" site ceases; the
Fühlungshalter aircraft communicates directly with Divisional
Headquarters through the receiver of the "Y" station and the
"Y" control officer stands by and listens to the R/T traffic
whilst maintaining a plotting control by the "Y" procedure.
31. According to P/W, the Divisional Plotting Centre at this
stage relies on Radar data for following the formations, and
only depends upon the Fühlungshalter aircraft to supply
immediate details of such circumstances as withdrawal of
fighter cover.

II. "Y" CONTROL SITE, AND IT’S OPERATION.
"Y" CONTROL SITE.
Manning.
35. A "Y" control station requires nine men per shift, or
27/30 men per 24 hour, for its operation and a site consisting
of nine stations is normally occupied by a company of 150/160
operators and 50/60 maintenance personnel. The personnel of
the "Y" control station is distributed as follows:
Transmitter hut: One operator.
D/F Cabin: D/F Operator and log-book
keeper.
Range-Measuring
Cabin:
A Supervisor, range-measurer
and log-book keeper.
Plotting Room: Plotter (friendly plots),
plotter (enemy-plots)
and plotting officer.
Communications.
36. Internal: The standard layout of the internal system of
commutations in a "Y" site is shown diagramatically in Sketch
II. In this Sketch "Station A" shows the general layout
applicable to all five stations, while "Station B" shows a
diagram of the internal communications which are in reality
repeated in all five stations.
37. The internal lines which are shown in the Sketch have the
following names and functions:
(a) Plotting line (Werteleitung): A telephone connecting
the log-book keeper in the D/F cabin to the range-measuring
cabin and "Y" plotting room for transmission of bearing
readings. (R in Sketch).
(b) Telephone (Ringleitung): Connects the D/F cabin, the
range measuring room and the transmitter hut for the passing
of internal instructions. (I in Sketch).
(c) Modulation line (Modulationsleitung): Connects the
range-measuring unit to the transmitter for carrying the
modulation note. (M in Sketch).
(d) Diode line (Diodenleitung): Connects the rangmeasuring
room to the transmitter hut; required only when a
Siemens range-measuring unit is used. (D in Sketch).
(e) Receiving line (Hörleitung): Open line which connects
the receiver and the range-measuring unit to the control desk
in the plotting room; a parallel line also runs to the
Division. (H in Sketch).
(f) Transmitter Circuit (Besprechungsleitung): Open line
which connects the Division and the plotting room to the
range-measuring unit. This can be used as a closed line for
internal speech or as an open line for transmission of R/T
instructions to the aircraft from the Division or the "Y"
plotting officer. (B in Sketch).
(g) Keying circuit (Tastleitung): Open line which
connects the Division and the "Y" plotting officer to the
range-measuring unit and transmitter. Depression of a key at
Divisional Headquarters or on the "Y" plotting officer's
control desk operates relays to the transmitter and modulation
line of the range-measuring unit, allowing R/T instructions
from the Division to be transmitted on the carrier wave to the
aircraft under control. (K in Sketch).
38. According to P/W, the twenty Channels connecting the five
stations of the site to the Division may be carried on two
single lines utilising a multi-channel carrier frequency
equipment.
39. External W/T Channels: The number of external W/T channels
varies, depending on the location of the control site, but
usually consists of the following:-
(a) Command network star (Befehlsstern d. Ln. Regt.) for
reception of tactical orders and general administrative
business from and to the headquarters of the Ln. Regt. to
which the company operating the "Y" site belongs - a Saram or
FuGe.3 set is used for this traffic.
(b) Divisional signals star (Divisionsbefehlsstern), used
for operational orders and transmissions of range values in
the event of failure of the ground lines to the Division. This
traffic is also usually conducted on Saram or FuGe.3 sets.
(c) Aircraft reporting frequency (Frontflugmeldewelle, or
more recently Gerätemeldewelle). On this channel W/T
transmissions are received from all Radar search sites giving
briefly the important data relating to aircraft activity
taking place within the area of the site. This transmission
takes place by day and night and supplements and confirms
information on enemy activity received from the Divisional
Headquarters; messages are written out and handed to the "Y"
plotting officer. A pack type W/T set is used for reception of
this traffic.

Brummer Relay Stations.
40. According to P/W, Brummer relay stations are placed
throughout German territory and are employed for relaying R/T
speech in cases where aircraft have flown beyond the normal
R/T range of the "Y" site.
41. The Brummer stations are connected to the Division H.Q. by
landline and are controlled by the Division; should a "Y"
plotting officer find that an aircraft under his control is
nearing the limit of R/T range, he will request the Division
H.Q., to connect with a Brummer station in the relevant area.
42. Whilst making this request, the "Y" plotting officer
states the frequency on which the "Y" station is operating,
and the Brummer will transmit at that frequency. According to
P/W, the R/T traffic on Brummer stations is usually confined
to directional and homing instructions, although "Y" control
can sometimes continue after the limit of R/T range of the "Y"
site has been reached.

Plotting Hut and Operational Procedure.
43. The plotting rooms of the five stations belonging to "Y"
sites are grouped, in a single hut known as the "Auswertung"
(plotting centre). According to P/W there are two types of hut
at present in use and a plan view of both these types is shown
in Sketch III.
44. The older type of hut contains a separate plotting room
and table for each of the five stations, but this type of
control contra is said to have offered no satisfactory method
of centralised supervision of plots and each plotter had to
act on his own responsibility.
45. The improved type of plotting hut has been developed by
the Flugmeldedienst (aircraft reporting service) and is
believed by P/W now to be widely in use in Germany. In this
type of hut a series of six tables is arranged on one side of
a rectangular room and each table is fitted with the normal
control point and is occupied by an M.C.O. plotter. The chief
plotting officer's table and control point are placed behind
the row of tables in such a position that he has a view of all
proceedings.
46. The reason, for the six plotting tables is that on some
"Y" sites the "Egon" method of fighter control is practised in
addition to the normal "Y" control and an extra plotting table
is set aside for this purpose.
47. According to P/W the Seeburg table has been withdrawn from
the majority of "Y" sites in favour of the present simple
method of plotting. In front of each group of three tables is
a vertical glass screen marked with the German fighter grid
and the main outlines of a 1:300,000 map of the area of
control.
48. Behind each screen are four plotters, three of whom
receive and plot friendly bearing and range values on the
reverse side of the glass screen. Plots are compiled from
range and bearing data in the range-measuring room of each
station and are passed through to these plotters in terms of
the fighter grid; the fourth plotter is responsible for
receiving and marking enemy plots.
49. All plots are numbered and in addition the courses drawn
on the glass screens during each operation are copied on to a
sheet of paper for record and reference purposes.
50. The extremely close and continuous contact with the "Y"
controlled aircraft enables the plotting control officer
immediately to detect any deviation of the aircraft from the
correct course and to rectify the error by ordering a slight
correction of course when necessary.
51. The plotting officer bases his instructions to the
controlled aircraft on the estimated position of the friendly
and enemy aircraft; in doing this an allowance is made for a
delay varying from five to ten seconds between the times of
the observations of enemy aircraft when originally made and
when finally received and plotted. By experience, specific
allowances are made for the extent of the delay from the
various stations supplying enemy plots.
52. When the fighters are nearing the limit of the range of
the "Y" site, the "Y" plotting officer is responsible for
handing the aircraft over to the next station; he must advise
that station, through Divisional Headquarters of the receiver
and transmitter frequencies in use, since the new station may
have been operating on other frequency channels. This step is
taken sufficiently early to allow the new station taking over
control to tune in on the R/T traffic of the controlling
station.
53. The "Y" plotting officer's task ceases for the time being
when the control aircraft or accompanying formation is brought
in sight of the enemy or, in the case of night-fighters, when
the aircraft is sufficiently close to its target to be able to
make an attack with the aid of search equipment.
54. Plotting by the "Y" station continues throughout the
sortie and combat of a fighter interception force, and does
not cease until the aircraft return to base after combat.

A.D.I.(K) S.D. Felkin
23 Sept.’44. Wing Commander"

[Bruce Dennis]

"SECRET A. D. I. (K) Report No. 390/1945
THE FOLLOWING INFORMATION HAS BEEN OBTAINED FROM P/W
AS THE STATEMENTS HAVE NOT AS YET BEEN VERIFIED, NO
MENTION OF THEM SHOULD BE MADE IN INTELLIGENCE
SUMMARIES OF COMMANDS OR LOWER FORMATIONS, NOR SHOULD
THEY BE ACCEPTED UNTIL COMMENTED ON AIR MINISTRY
INTELLIGENCE SUMMARIES OR SPECIAL COMMUNICATIONS.

RADIO AND RADAR EQUIPMENT IN THE LUFTWAFFE – X.
German early warning Ground Radar.
1. This report is the tenth of the series dealing with radio
and radar equipment in the Luftwaffe. As in the case of the
previous nine reports (A.D.I.(K) 343, 357, 362, 365, 369, 370
and 330/1945), it is based on interrogation of General
Nachrichtenführer MARTINI, Director General of Signals, and
some members of his staff, and has been supported by a number
of relevant documents of recent date which were in the
possession of the General's Chief of Staff.

DEVELOPMENT OF EARLY-WARNING RADAR.
Early History.
2. As recounted in A.D.I.(K) 343/1945 and again mentioned in
A.D.I.(K) 365/1945, the Freya, which became the first standard
early-warning radar set for the G.A.F., was developed by the
firm of Gema, Berlin, with the encouragement of the Navy. The
first Freyas were in operation as naval coast watchers in 1938
at a time when the G.A.F. was only thinking of radar in terms
of searchlights and Flak.
3. The Technisches Amt wished to push 50 cm. wavelength
like that of Würzburg, but the Navy backed the longer
wavelength of Freya, and General MARTINI, who immediately
appreciated the advantage of a wide-angle apparatus of Freya
type to early warning, asked that a number of Freyas should be
allocated to the G.A.F.
4. In early 1939 one of the present P/W, Oberst Ing. HENTZ
was selected from among the Köthen staff to take charge of the
first experimental Freya used by the G.A.F. in that year.
It was thought at first that the Freya would only give
indications over the sea, but during the march on Prague in
the first part of 1939 an experimental Freya was set up in the
Riesen Gebirge in order to watch Czech aircraft which might
react to the German advance. This experiment was not a
success, as the signals operators had not been expecting to
find their tube cluttered up with permanent echoes.
5. At the outbreak of war the G.A.F. possessed eight Freya
stations distributed round the East and North Frisian islands
guarding the Heligoland Bight and the approaches to the North
Sea ports. These Freyas proved their value during the early
Bomber Command raids on Cuxhaven and Wilhelmshaven etc., when
some outstanding successes were registered by German fighters,
which were vectored on to the bomber formation as a result of
the early-warning obtained by the Freyas. It was this success
which convinced the G.A.F. of the practicability of radar as
an early-warning device.

Early Developments.
6. The range of the early Freya was of the order of 80 km and
their accuracy of the order of a few degrees. No height
finding facilities were available. The height finding problem
at close range was solved by directing a Würzburg on to the
target when it came within the range of the latter, which in
these days was about 30 km. This system of height measurement
continued to be the only practical one for a long period,
although the field operators had put in requirements for
height finding Freya apparatus as early as 1940.
7. Experiments by the G.A.F. produced the Wassermann, but
the German Navy experimented with the object of introducing
height finding facilities in the Freyas, and the N.V.K. at
Pelzerhaken produced the "Chinese" and "Tiefland". The former
gave maximum location by means of a compensator in an serial
system inclined at 45° and was used for angles greater than
15°, whilst the latter was intended for angles less than 15°.
The combination of the two mounted on the Freya was known as
the “Malaya”.
8. Measurement of height with the Tiefland was possible
between 2° and about 15° over level terrain; measurement of
angles of less than 5° was, however, very inaccurate and range
was actually less than that of the Würzburg-Riese. Over uneven
terrain, measurement of the vertical angle was impossible.
9. The Tiefland had the disadvantage of being complicated in
operation - a large field of reflector nets was also necessary
- in addition to which it gave no better performance than the
Würzburg-Riese. Its use would only have been justified had it
been a device which could be moved easily and quickly and had
there not been restrictions on the selection of suitable sites
for its mounting.
10. Freya Fahrstuhl was designed by Köthen as early as 1943
but was never put into large-scale production, and was not
satisfactory. This apparatus depended on the difference of
phase observed between direct ray and ground reflection to
give height.
11. Finally, in 1944 methods or swinging the beam
electrically were used in the Wassermann for height
measurement, but the Würzburg remained the basic means of
measuring the elevation up to the end of the war. The D/F
accuracy of the Freya was greatly improved when the split beam
or A.N. technique was introduced in 1942, end this made Freya
valuable for fighter control on the Egon system.
12. The range of Freya, naturally dependent on height of an
objective, was about 150 km. but this was not considered
sufficient for the early-warning service and efforts were made
in 1942 to produce early-warning apparatus with greater range.
The first of these was the Wassermann which improved the
early-warning range to about 200-250 km, while the Mammut,
used by the Navy for coast watcher purposes, was also used by
the G.A.F. and gave ranges up to about 300 km. Finally
Elefant, which gave ranges up to 350 km., was built and came
into operation in about 1944.
13. By the middle of 1943 an elaborate early-warning service
covering the whole of Germany and composed of sites with both
Freyas, Würzburgs and Giant Würzburgs had been built up, and a
number of Wassermann chimneys were in operation along the
coast of Europe.
14. The great improvement in D/F accuracy resulting from the
split beam technique was utilised by KAMMHUBER to develop his
box system of night fighting, and in fact at this time it was
strictly forbidden for a night fighter to fly any form of
night defence other than the close control of the KAMMHUBER
box system.
15. Other methods of fighter control namely the Egon and
Bonito, were under development, and of these the former also
used the Freya wavelength for range and D/F.
Effect of first use of Window.
16. When Window was first used in July 1943 the whole of the
early-warning system as well as the night fighter control
system broke down completely.
17. The first German reaction to the use of Window was to
attempt to filter it out or obtain some method of
distinguishing between blips due to window and those due to
the aircraft itself. Virtually no work had been done on this
problem before July 1943 because GOERING had been so
frightened by the prospect of Window being used by the enemy
that the theoretical possibilities had been hushed up and
scientists has not being allowed to work on the problem (cf.
A.D.I.(K) 334/1945).
13. Nevertheless, when Window was first used by the Allies, it
was only a matter of some ten days before the first solution
to the Window problem for the Würzburg was forthcoming in the
shape of the Würzlaus, which relied on the Doppler effect.
High priority was given to the problem and even money prizes
were offered for solutions.
19. Three main types of equipment were evolved as a result of
the various solutions proposed; one was Taunus, which gave
greater blip resolution, another was the propeller modulation
type such as Nürnberg and the third was based on the Doppler
effect, the latter being termed Laus A—J devices. Of these the
Freyalaus for Freya and Wasserfloh for the Wassermann were not
used operationally till 1944.

Effect of Further Countermeasures.
20. As Allied countermeasures became more intense and
electronic jamming was also used, the signals staff decided
that it should be the genera1 policy to provide all types of
radar with the facility for a change of frequency. The first
efforts to do this were brought about by mechanical trombone
tuning of the aerials so that two or three neighbouring
wavelengths could be used. This was termed the WISMAR
principle.
21. Sometime in 1943 Dr. SCHULTER of the firm Siemens
developed the Breitband (wide band) aerial which enabled a
much greater frequency spread to be used. This principle was
termed Voll Wismar and with increasing experience was to be
applied to all types of ground radar. At the same time Freya
and Würzburg were allotted different "Inseln" or frequency
bands in the hope that some of these bands would not be jammed
locally. This policy was carried to great lengths, but Allied
countermeasures still remained extremely effective.
22. Either owing to the weakness of German centimetre
technique, or to a lack of appreciation of the value of
centimetre wavelengths, the main trend in avoiding British
countermeasures was towards longer wavelengths, and special
Köthen Freyas using wavelengths of 5 and 8 metres were
prepared. When jamming on the more normal wavelengths
became severe these reserve sets were operated for a minimum
period often only a few seconds, in order not to compromise
the wavelength, and an effort was made to obtain a clear
picture of the air situation with their aid.
23. Eventually wavelengths up to 13 metres came into use for
early-warning with giant sets such as Elefant.
British Transmissions as an Aid to Early Warning.
24. Despite all these precautions, and despite the fact that
P/W claimed that many of these wavelengths were not
effectively jammed, it frequently happened that the earlywarning
service was unable to obtain a clear picture of the
situation and recourse had to be made to indirect means. The
monitoring service was of particular value in this respect,
and they successfully maintained their point of view that it
was not worthwhile jamming the fighter R/T because D/F’ing of
this provided excellent early warning.
25. The fact that British night bomber crews were in the
habit of using Monica and H2S from the very beginning of their
flights was also of great assistance in supplementing the
early-warning picture. In the same way Allied I.F.F. was of
great value, and special Freyas known as Freya Flamme which
covered the I.F.F. frequency band were erected on some
important early-warning sites.
26. Finally, an ingenious system which was invented by Oberst
Postrat SCHOLZ called Klein Heidelberg utilised the reflection
of the transmissions from British C.H. stations and was
regarded as virtually unjammable.
Development of Panoramic Presentation.
27. As early as 1940 a requirement was put up for a panoramic
presentation for early-warning radar, but no great progress
seems to have been made until the discovery that H2S was using
a P.P.I. successfully. Difficulties were encountered with the
early types such as Propeller developed by Lorenz and it was
not until early 1944 that the Jagdschloss sets came into
existence. These were originally used entirely for early
warning and not with the idea that night-fighter aircraft
could be controlled with their aid. It was not until 1945,
when the value of Jagdschloss was fully appreciated and it was
numerous enough to cover 1st class radar sites throughout
Germany that some efforts were made in its employment for
control of night fighters.
28. With the intended introduction of Neuling I.F.F., which
could distinguish not only between friend and foe but between
individual crews as described in A.D.I.(K) 365/1945, fighter
control from panoramic presentation was to be greatly
extended.

SPECIAL PROBLEMS AND APPLICATIONS ON GROUND RADAR.
Day Fighter Control.
29. The necessity for day-fighter control from ground radar
stations was early appreciated by the Signals staff, and the
Battle of Britain proved to them how successfully it could be
used by air force inferior in numbers. Spasmodic attempts were
made to introduce it into the G.A.F. but the German fighter
tradition was too strong, and the pilots would not accept
ground control.
30. It was not until 1943 that close ground control on the
Egon system using the FuGe 25A in the aircraft was introduced.
Control of Night Fighters.
31. With KAMMHUBER’s box system two Würzburg sets were used -
one to follow the target and one to follow the fighter, the
positions of each being projected on to the map by means of
the so-called Seeburg Tisch. So long as there was no jamming
of ground radar, this method was successful and could place a
fighter within 200-400 metres of the target. Later the
Würzburg Riese was used and the majority of these sets were
allocated for this purpose.
32. A suggestion had been made that the Würzburg 50 cm.
transmission should be used simultaneously for giving the
fighter his vectors and a system named Sprechstange was
experimented with. It was rapidly found that, if the operator
failed to hold the fighter in the beam, the pilot received no
instructions from the ground, and so vital instructions might
not be heard. For this reason it was soon abandoned as not
practicable.

I.F.F. Problems.
33. The FuGe 25A was originally designed by the firm of Gema
for use with the first Freyas operating on 2.4 metres. As
recounted in A.D.I.(K). 365/1945 it became the standard German
airborne I.F.F. set in 1942 and was used with the Kuh
transmitter and Gemse receiver on all ground radar
installations, whatever the wavelength, with the exception of
the Würzburg series. A full description of the problems of
ground radar has been given in the above-mentioned report.
Plotting of High Flying Aircraft.
34. In 1944 it was found that the very high level Mosquito
bomber attacks on the Reich sometimes crossed the coast
unplotted, and at best were only detected intermittently after
passing the coastal screen of Wassermanns which could swing
their beams upward electrically. The reason for this was that
the main lobs of Freya only went up to about 8,000 metres.
There were two subsidiary lobes, the higher of which reached
to 12,000 metres, but the latter only gave limited coverage at
this height over an estimated range of 70 km.
35. The Würzburg beam was too narrow and did not give general
coverage, while Freya Fahrstuhl, which could also be utilised
for aircraft flying at great height, had hardly been
introduced into operations. For this reason considerable use
was made of the Würzburg Riese-G which was a Giant Würzburg
with a very narrow 50 cm. beam, with additional Freya aerials
on 2 metres, set in the paraboloid, giving a wide beam
coverage as well. As the circle paraboloid could be tilted
upwards, excellent high coverage was obtained and high fliers
were plotted with its aid.

Plotting of Low-Flying Aircraft.
36. The Germans were fully aware of lack of low cover, which
enabled aircraft flying low over the sea to cross the coast
unnoticed. A number of experiments were conducted to overcome
this disadvantage by placing special aerial arrays at
considerable height above the ground as for instance in the
case of the Würzmann using the Würzburg frequency and the
Tiefentwiel using the Hohentwiel A.S.V. frequency.
37. Some experiments were also conducted with wavelengths of
about 20 metres with the idea, it was believed, of making use
of the curved path which those waves followed. The experiments
were never completed, as this band was interfered with by
communications signals transmitted on the same wavelength.
38. Experiments had also been made at Köthen with Taunus
equipment coupled to the Freya to obtain extremely high
resolution. A Fieseler Storch aircraft was used, flying at 150
metres over flat country, and under these conditions the
aircraft could just be seen at ranges of 4 or 5 km. through
the ground returns due to woods and houses. It was concluded,
however, that this range was so small that no advantage was to
be gained.

GROUND RADAR INSTALLATIONS.
Freya.
39. Freya was manufactured by the firm of Gema, Berlin,
which, at the outbreak of war, was only a small establishment
largely financed by the Navy. Members of the Technisches Amt,
as well as of MARTINI’s staff, criticised the firm, severely,
saying that they lacked experience of manufacturing and were
unwilling to make themselves adaptable. They described the
Freya Stand for instance as a “cast iron monstrosity”, which
they felt could easily have been made very much lighter in
weight and manufactured more simply.
40. Despite this complaint against Gema, it was a principle
that all ground radar apparatus should be of fairly simple
construction so that it could be made mobile. A few days after
the invasion of Norway the Germans were experiencing
considerable trouble from bomber raids in the Stavanger area
and an urgent request was sent out from there for a Freya to
be supplied. This job was given to one of the present P/W, and
within three days of receiving it a Freya LZ Stand had been
dismantled and packed into three Ju.52's and transported to
Stavanger. Eight days after the reception of the order the
Freya was operating.
41. At the beginning of the war the G.A.F. possessed eight
Freyas. At the end of the war over 1,200 had been manufactured
and a document dated 1st January 1945 states that 671 were in
operation at that time.
42. Owing to the incidence of all forms of Allied jamming,
the original wavelength of 2.40 metres had been modified very
considerably. The following impressive list of wavelengths
current at the beginning of November 1944 was found among
documents brought by General MERTINI’s staff:-
M. M.
Insel A
Insel B
Insel C
Insel D Band Z
- 2,32-2,45
- 2,08-2,24
- 3,00-3,30
- 1,50-1,55
Köthenband gelb/braun
Köthenband gelb/rot
Köthenband Ludwig
Köthenband gelb
1,70
1,80
1,95
2,00
Y
X
W
V
U
T
Vollwismar
Bereich I
II
III
- 1,55-1,60
- 1,60-1,65
- 1,65-1,70
- 1,70-1,75
- 1,75-1,80
- 1,80-1,85
- 1,90-2,50
- 1,20-1,90
- 2,50-4,00
Köthenband gelb/grün
Köthenband grün
Köthenband rot
Köthenband braun
Köthenband weiss
Köthenband schwarz
Köthenband blau
Köthenband violett
Köthenband grau
Köthenband blau neu
2,56
3,15
3,40
3,65
4,05
4,60
4,80
5,20
5,75
8,80
43. In addition to this formidable list P/W states that in
early 1945 experiments were being made with a Köthen Freya on
about 12 metres. The Köthen Freya with wavelengths of over 4
metres presented a problem to the aerial experts which was
being solved by using Yagi aerials mounted above the normal
aerial mattress. Although it was considered desirable to mount
the aerials at a height above the ground of at least ten times
the wavelength, this was not always possible; for instance the
Yagi aerial of Köthen Blau (4.80 metres) was, according to a
document, to be mounted 30 metres above the ground.
44. Two further new wavelengths known as the Rotschwarz and
Grünschwarz were planned and were to operate on two of the
frequencies used by British Gee in the hope that they would
not be jammed. It was realized that these wavelengths could
only be used when the jamming of Gee by Heinrich transmitters
was not being carried out. The Freyas so equipped were to be
located as far as possible from the positions of the Heinrich
jamming transmitters.
45. In order that these longer wavelengths should not be
compromised, a so-called Kurz Zeit apparatus was built into
the Freyas which allowed transmission of only ten impulses and
prevented more impulses being emitted for a period which could
be set between 2 and 22 seconds. It was considered unlikely
that listening aircraft would be able to tune to these short
interrupted pulses.
46. A document, dated June 1944, in the possession of a
member of General MARTINI's staff, contains a short history of
the jamming experienced by Freya. Extracts from this document
are given below in free translation:
"Jamming by Jamming Transmitters.
"In April 1942 the jamming of Freya on the original 2.40 metre
wavelength was reported.
"On 5th March 1942 the Chef N.V.W. put up a requirement to the
Technisches Amt asking that alternative frequencies for Freya
should be made available, basing his request on the fact that
parts of a Würzburg, from which the exact wavelength could be
determined, had fallen into enemy hands during the Cap
d'Antifer (Bruneval) raid on 27th February 1942. By the end of
1942 the original Freya wavelength was being jammed generally.
"As no steps to provide alternative frequencies in operations
had at that time been taken by the Technisches Amt or by
industry, Ln. Versuchs Regiment Köthen was asked to use its
resources to provide them.
"After about one month, on 15th June 1945, the first Freya
which operated in an unjammed band, the Köthen Grün, was
handed over to a unit for operational use.
"In 1942, Freya on Insel B and Insel C had been demanded from
the industry but they were not delivered until 1943. The Insel
B sets were first available on 23rd February 1943, but shortly
after being used operationally were jammed by the Allies. The
Insel C apparatus was made available on 10th July 1943 and has
been in regular production until the last few months.
"It must be recorded at this point that the first new Insel
was produced by the industry about a year after Köthen had
produced an improvised apparatus. Moreover, the Technisches
Amt and industry were unable to give the Signals branch a
Freya which was not jammed. Assistance had to be sought from
Köthen, who produced Köthen bands which alone enabled the
further operation of Freyas to take place.
"In view of the jamming situation the Chef N.V.W. demanded on
19/12/42:-
(a) Freya frequencies below 1.90 metres.
(b) A Voll Wismar band which allowed constant frequency
change
(c) Long waves over 4 metres, with the suggestion that the
Yagi aerial arrays should be used.
"The following comments must be made on the foregoing
demands:-
(d) The first Freya below 1.90 metres (Flum 41) became
available on 2/7/43.
(e) The first Voll Wismar was delivered in May 1943, but in
spite of this the first mass-produced apparatus was not
available until July 1944, and then only in small
numbers.
(f) The problem of long-wave Freyas was never taken up by
either the Technisches Amt or by industry. This problem
was solved by the development by Köthen of Yagi
aerials, and these were first built into operational
sets in September 1944.
"Jamming by Window.
"The possibilities of jamming by Window were made quite clear
on 17/3/1943 and a requirement for an anti-jamming device for
all radar apparatus was formulated. Not until 19th June 1944,
that is, one year and three months later, was the Freyalaus,
which had been developed by ZVH, made available by the Chef
TLR.
"Since it was clear that a change-over to longer waves to
avoid Window was the only possibility available at that time,
the only solution was the use of long-wave apparatus (Yagi
Köthen Grau). With this type of equipment it has been possible
for some months to obtain an early picture free from jamming.
Further Yagi wavelengths were developed and units are being
equipped with them.
"To make recognition of new radar wavelengths impossible for
the enemy, a short transmission system (Kurz Zeit Messung)
described above was formulated as a requirement on 23/9/42. At
the data of writing this has not yet been introduced."
48. The decision to avoid Window by using longer wavelengths
appears to have been taken on the results of some experimental
work. When Window 1.80 metres long was produced against SN2,
Insel C was severely affected, and research work was done on
the susceptibility of different wavelengths to Window of this
length. The diagram produced in Appendix I shows the effect
produced by a standard quantity of 1.80 metre Window at a
range of about 70 km. on various types of Freya.
49. As a result of this experimental work, the Signals staff
realised that it was an advantage to increase the wavelengths
as the intensity of the signal received fell off sharply above
3.80 metres. It was considered impracticable to put a longer
Window into use and as a result the so-called-Köthen bands
were produced.
50. The Germans were unaware that we were dropping very long
Window {rope) at a later date. A certain number of specimens
of this had been picked up and it had been assumed that it had
something to do with meteorological observations.
51. In an interesting publication Funkmessnachrichten No. 19
dated 25th February 1945, it is stated that the C-Insel of
Freya suffered worst from jamming by ground transmitters but
gelb-rot, grün, braun, weiss and grau Köthen bands and the A,
B and D Insel were also jammed at times.
52. Airborne transmitters were beginning to jam the Köthen
grau band, while Köthen braun and D Insel experienced
occasional interference by airborne-electronic jammers. Only
on one occasion had jamming of the Köthen weiss been observed
from the air.
53. The G.A.F. was vitally interested in the Köthen grau band
which was the main stand-by for the early-warning service, and
it was this band and the Köthen blau on 8.80 metres about
which instructions had been given that they were to be
switched on only for very short time in emergency. About 40
Köthen grau equipments were in operation.
54. The range claimed for Freya was 80-120 km., with a range
accuracy of ±300 metres and D/F accuracy with split beam
(A.N.) 1/3°.
55. It is stated in the same document that by February 1945
all Freya equipments, with the exception of some motorised
units, had been fitted with the Freyalaus. A new type of A-J
device, which is however, not described, named the Prüflaus
was at this time being tested on a few sites.

Freya Flamme.
56. A certain number of Freyas in the Insel D band were set
aside for the purpose of triggering off British I.F.F. when
this had been left on in aircraft inadvertently. It was
claimed that, provided the aircraft was flying at a
considerable height, ranges of up to 450 km. had been obtained
with the Freya Flamme. D/F was difficult due to the wide
spacing of the short pulses and no continuous echo beingobtained.
The Germans were aware that six codes were
transmitted by British I.F.F. and believed that they know the
significance of the various identifications.
57. Initially this proved a most useful very long-range early
warning, but the number of aircraft flying with I.F.F. had
been greatly reduced during the last year of the war.

Freya Fahrstuhl.
58. The Freya Fahrstuhl, designed by Köthen, is a Freya with
height—finding facilities obtained by making use of the
reflected ground wave. It was first introduced in early 1943,
but owing to unknown causes, a certain amount of trouble was
experienced and only about eight equipments were in operation
on 1st January 1945. The original requirements were formulated
in 1940 for a Freya type apparatus to give elevation.
59. This set had a range of 220 km. and was used for height
finding by the early—warning service and also as an aid to
Flak if the Würzburg were jammed. The wavelength used was 2.00
metres (Köthen gelb). The Freya Fahrstuhl was originally
intended as an early-warning radar giving height, but the few
produced were largely used to give height to Flak when the
latter's Würzburg was jammed.

Würzburg.
60. The history of the development of this apparatus will be
told more fully in the next and final report of this series
which will deal with German Flak radar, for which purpose it
was originally designed.
61. The original Würzburg Insel A had no split beam D/F but
was nevertheless used for early attempts to control night
fighters.
62. The frequency used by Würzburg A was a single spot
frequency, between 53.0 and 54.2 cm. It was first introduced
in any quantity for raid reporting purposes in the autumn of
1940, when it was used to obtain the height of aircraft
observed on the Freya. Its maximum range was about 25 km.
63. The next type introduced was the Würzburg C with A.N. D/F
facilities and range of 25 km. The first Würzburg C’s came
into service in the summer of 1941. A few were used for
controlling night fighters, but the great majority was used by
Flak. The Würzburg C’s were on fixed frequencies in the band
53.0 to 54.2 cm.
64. The final form of Würzburg, the D, had still only a 25
km. range operationally, but was a general improvement over
the C with split D/F facilities giving an accuracy of ± ½° and
range accuracy of ±50 metres. It was introduced in the autumn
of 1941 believed to have been used for Flak purposes only.
65. The original sets were in the frequency band known as
Insel A 53.0 - 54.2 cm but later a B band from 56.7 to 58.0
and a C band from 62.3 to 63.8 were introduced.
66. Finally a Würzburg was manufactured with wide band
aerials using the Urechse equipment which allowed any
wavelength between 53.0 and 63.8 cm. to be used. The Urechse
transmitter was being generally introduced in the spring of
1945.

Würzburg Riese.
67. The Würzburg Riese was introduced in 1941, and from the
beginning was mainly used for the close control of night
fighters on the Himmelbett system. In all, 452 sets were in
operation on 1st January 1945. A few sets were used for
providing the Gross Batterien, situated at Berlin and other
places, with information for their anti-aircraft operations,
but these were of the Riese G (Gustav) type with Freya aerials
incorporated in the paraboloid, so that a 50° wide search beam
was provided as well as the 13° main beam on 50 cm.
68. The wavelength used for the Freya section of the Riese G
was originally 2.20 Metres, but wavelengths of 1.80 metres and
1.70 metres were also introduced, and it was intended to use
1.60 metres in the future. The Würzburg section of the Riese
used the A and B Insel of the Würzburg bands, namely 53.0 -
54.2 cm. and 56.7 - 58.0 cm. The range of the Würzburg Riese
was about 70 km. and its range accuracy was of the order of
±50 metres.
69. Some ten of the sets used for Flak were provided with
Voll Wismar using the Schwarz Echse transmitter on a new
wavelength of 1.50 metres.
70. The additional Freya wavelength was found to be
particularly valuable against U.S. day bombers, which usually
only jammed the Würzburg 50-60 cm. band and left the Freya
band unjammed.

Wassermann.
71. The original purpose for which Wassermann was introduced
was to obtain a more powerful early warning radar with a
greater range than Freya, and it was therefore the G.A.F.
equivalent of the novel Mammut. Three main types of Wassermann
were produced, the L, S and M.
72. The Wassermann L (Leicht = light) was produced by Gema
and was said to have a range of 200 km., an accuracy in D/F of
± ½° and in range of ±5 km. The first set came into use about
the summer of 1942; two types were manufactured, namely L.I,
on 2.40 metres and L.II on 2.01-2.27 metres, in which spot
frequencies (Streuwellen) at 15 mc/s intervals were available.
About 25 of these were built. They were constructed as lightly
as possible so that they would be transportable, which was
considered specially important for the Balkans and in Norway.
It was estimated that they took about 3-4 weeks to erect. They
had, however, a disadvantage that in strong winds the whole
tower was apt to be blown over.
73. The Wassermann S (Schwer = heavy) was also constructed by
Gema and its accuracy was comparable with the L, except that
ranges of 300 km. were obtained. The first equipment was
erected towards the end of 1942 and in all some ten became
operational. The first seven sets erected (S.1 to S.7) used
wavelengths of 2.40 or 2.46 metres. These numbered S.8 to 10
used 2.36 metres, 2.34 metres and 2.29 metres. These sets took
something over 4 months to build, but they were at least more
robust than the Wassermann L.
74. The final form of Wassermann, the M. (Mittel =
intermediate) was designed by Siemens. Its accuracy in D/F and
range was about the same as the other two types but a maximum
range of about 220 km. was obtained.
75. The first types introduced were the M.I and M.II in the
autumn of 1943. Both used frequencies in the 2.01-2.20 metre
band but the M.II allowed different frequencies within this
band to be used on the Wismar principle.
76. The M.III used the 1.20-1.90 metre band, and was of the
wide band Voll Wismar type but only two sets were built, as it
was succeeded in the spring of 1944 by the M.IV which gave
wide-band facilities from 1.90-2.50 metres. Some twelve M.IV.
were in operational use by January 1945, and more were being
produced.
77. The latest form of Wassermann was to be the M.V. which
was a wide band equipment working on 2.50-4 metres, of which
one experimental set had been set up on the Baltic coast.
78. Since about the beginning of 1944 an electrical
compensating arrangement had been built into the Wassermann
which allowed the beam to be swung in elevation, and an
elevation of about 15° could be obtained. The A-J device
Wasserfloh with Doppler effect was fitted first towards the
end of 1944.
79. Generally speaking the Wassermann was a disappointment.
Production of Elefant was postponed as the original estimate
of Wassermann's range, as late as autumn 1943, was that it
would give 400 km. coverage. Wassermann never succeeded in
giving coverage much over 200 km.

Mammut.
80. This coastal radar equipment which was known to the
Allies as the "Hoarding" was really a Naval coast-watching
radar of which some 8-10 specimens were operated by the
Luftwaffe. It had the advantage that the polar lobe was well
beamed - more beamed than the Wassermann - and, therefore, it
was not very susceptible to jamming but it took about 8 months
to erect and was costly and unvieldy. The comparatively narrow
lobe scanned electrically by means of a phase shifter, termed
a compensator. The wavelength used was the original Freya band
2.40 metres and the range achieved some 300 km. No height
finding was available.

Elefant.
81. The Elefant, sometimes referred to as See-Elefant was
produced by the Reichspost and was designed in part by Ober
Postrat Dr. SCHOLZ. At the end of the war three equipments of
this type had been built and a further three were in course of
erection. The wavelength used was comparatively long, in
conformity with policy of escaping the effect of Window by
increasing the wavelength. Of the three sets built, two were
in the 7.90-8.80 metres band, and the remaining one in the
band from 10.70-12 metres.
82. A D/F accuracy of 1° was obtained and range accuracy of
±4 km. The first set was created in the summer of 1942. But it
underwent constant improvement and its form was not finalised
until 1944. In November 1943 the Technisches Amt refused
definitely to sanction the large-scale introduction of Elefant
as although a range of 400 km. was obtained similar results
were expected (but never obtained) from the Wassermann. A few
were, however, built by Köthen in the field.
83. In order to prevent the long wavelength from being
compromised, the Elefant was only used for short periods and
when the air situation was not clear to the ear1y-warning
service. This was the more important as it was realised that
Elefant could easily be jammed. The normal array consisted of
two 100 metres high towers.

Heidelberg.
84. One of the present P/W believed that experiments were
being carried out with an early warning set on a wavelength of
between 18 and 20 metres which was to be called Heidelberg. He
understands that jamming interference was encountered, as the
set operated on the frequency band used by W/T traffic, and
for this reason the project was dropped. P/W stated that it
was hoped to obtain very great ranges, as the waves would
conform to the earth's curvature. There may, however, be some
confusion in his mind with the Klein Heidelberg system
described below.

Klein Heidelberg.
85. The name Klein Heidelberg was given to a system utilising
reflections from aircraft of the pulses emitted by British
radar stations or by distant German stations. Strictly
speaking, therefore, it was not a radar set at all.
86. The results obtained were satisfactory at the three
stations used, but at the time of its invention by Ober
Postrat SCHOLZ, in 1941, it was not regarded as of particular
importance, as their radar was not being jammed.
87. In 1944, when jamming became serious, the Klein
Heidelberg system proved of great value. Its D/F was poor but
range was adequate for early warning information.
88. It was noticed in October 1944 that our 25 cycle CH
stations had started to change their p.r.f. but a radio
locking system was improvised within six weeks and thereafter
no trouble was experienced. Tests were made to utilise the
Gee pulse sources, but the system worked adequately with CH
and the experiments were not pursued.
89. When he was interrogated on this matter Dr. SCHOLZ stated
that he understood that the results obtained at the Römö
station were surprisingly good, despite the great distance
from Great Britain.

Würzmann.
90. The Würzmann was the name given to an experimental
coastal set which was to be used for the location of low
flying aircraft. According to P/W, it was a Jagdschloss
Michael B aerial array set up on end. The aerial array of the
Jagdschloss Michael B consisted of a double row of 18 Würzburg
mirrors and measures not less than 56 metres x 7 metres.
91. This gigantic erection was mounted so that the electric
centre of gravity was 50 metres above sea level and produced,
in fact, a Würzburg beam which was very narrow in azimuth.
With its aid it was claimed that aircraft flying at 0 feet
could be seen at a range of 20 km.

Tiefentwiel.
92. Tiefentwiel was the code name applied to an aerial array
placed high above ground using the Hohentwiel A.S.V. set with
the intention of detecting low-flying aircraft coming in over
the sea. No details of the aerial array or method of operation
were known but it was stated that the Tiefentwiel achieved as
good results as the Würzmann, namely a range of about 30 km.

Hohentwiel Boden.
93. Funkmessnachrichten publication No. 19 announced the
introduction of a short-range highly-mobile early-warning
radar called Hohentwiel Boden which could be erected in 15
minutes. The set consisted essentially of the Hohentwiel
A.S.V. set with an aerial array mounted on the top of a 10'
high mast. This improvisation was carried out by the Ln.
Versuchs Regiment Köthen, who stated that individual targets
could be seen at a range of 30-35 km. and formations at 60-70
km. It was to be used in the front line to give advance
warning of raids.

PANORAMIC RADARS.
Propeller.
94. Some time in 1943 the firm of Lorenz produced an idea for
a P.P.I. presentation for early warning to which they gave the
code name "Propeller". This set relied on extremely rapid
rotation of the aerials and used a wavelength of about 50 cm.
95. Just before the set was officially demonstrated to the
G.A.F. it exploded. All the apparatus was lost and the project
was abandoned.
Jagdschloss F.
96. The first type of early-warning radar set giving
panoramic display which come into operation in usually
referred to as the Jagdschloss, although it’s official
designation is Jagdschloss F, to distinguish it from later
types, such as the Michael B and Z. It was produced by the
firm of Siemens and was first used in operations in early
1944. About 65 Jagdschloss F equipments had been manufactured
by the end of the war.
97. Equipments No. 1 to 62 were of the Voll Wismar type using
wide band aerials and covering the band 1.90-2.20 metres. From
63 onwards the frequency band to be covered was 1.20-1.90
metres. A document mentions Jagdschloss lang (=long) with a
wavelength of 8.0-10 metres. No information about this has
been obtained.
98. These sets were used exclusively by the early-warning
service and gave a range of about 100 km. with a D/F accuracy
of 1° and a range accuracy of 4.5 km.
99. The range accuracy depended largely on the presentation
on the 40 cm. P.P.I. tube. At 100 km. the area of error was
stated to be 5 x 5 km. but Köthen was attempting to improve
the presentation so that blips could be read to a greater
accuracy by introducing electrical range rings.
100. Another trouble that was being experienced in February
1945 was that the 50 cycle frequency at the national electric
grid affected the presentation so that the blips which should
have appeared as small arcs actually appeared as an arc with a
wavy out-line.
101. The P.P.I. tubes produced by Siemens were being modified
to avoid this imperfection while the Fernseh A.G., who also
produced tubes for Jagdschloss, were working on the problem.
It was believed that a new type of "Tonfrequenz" cable would
be necessary. Particular attention was being paid to this
point because of the difficulties in reading the tube caused
by window.
102. According to a document a new type of valve called the
Nullode was being introduced at this period to replace the
8D.6 diode in the Simultan unit.
103. It was proposed to introduce a selecting switch, by
means of which three alternative pictures could be produced on
the P.P.I. tube. The first picture showed all blips present on
the tube, the second position allowed the I.F.F. to be
switched in, while the third was a purely I.F.F. picture in
which only friendly aircraft with I.F.F. operating came up.
104. The I.F.F. problem had not been fully solved and it is
stated in a document that a separate FuGe control set is
necessary to assist in obtaining unequivocal identifications.
105. In this same document mention is made of the Münchhausen
system which was to use coloured photographic films to
distinguish between Windows and moving targets; stationery
targets would appear on the film as dark spots while moving
aircraft would appear as spots with red and blue edges in the
direction of movement. This system had been worked out at
Werneuchen and in February 1945 the first apparatus was in use
with a Jagdschloss equipment in the field. The film, however,
took between one and two minutes to develop.
106. Further difficulties in the form of dead zones were
being encountered with Jagdschloss and it is suggested in
Funkmessnachrichten publication No. 19 that a wire netting
surface with a radius of 50-60 metres should be built round
the Jagdschloss in order to get rid of the lower dead zone and
to aid in increasing the range against high flying aircraft.
It is stated that one ton of iron wire netting necessary for
each site.
107. According to P/W the electrical jamming of Jagdschloss
was never very severe, particularly as it had Voll Wismar. The
fact that it was causing trouble was, however, proved by the
fact that in Funkmessnachrichten publication No. 19 it is
stated that a number of special cameras had been provided and
were in use at various Jagdschloss sites to take pictures of
the type of jamming encountered in order to ascertain what
measures could be undertaken against jamming.
108. A so-called electric lens was to be used as a means of
seeing through Window. This was an arrangement whereby a
magnification of between 2 and 3 times natural size could be
obtained of a circular area of the picture. The area which
could be magnified could be chosen but was limited to circles
whose circumference passed through the centre of the tube, but
did not reach the edge of the 40 cm. P.P.I. tube.
Jagdschloss Michael B.
109. A ponderous aerial array of two rows of eighteen
Würzburg mirrors measuring 56 metres long x 7 metres high was
used in the Würzmann experimental early-warning radar, and
formed the serial array for Jagdschloss Michael B with the
array in a horizontal position. The wavelength employed, was
that of a Voll Wismar 53.0-63.8 cm.
110. By means of this aerial a beam of ½° horizontal width
was obtained and a range of about as much as 250 km on single
aircraft was expected. It was also expected that the narrowbeaming
of Michael B would be of great assistance in avoiding
Window. The dead zones were to be overcome by switching the
frequency to another wavelength in the Voll Wismar band II,
which was believed to run from 50-60 cm. The first set was to
be ready in April 1945.

Forsthaus F.
111. This apparatus was designed by Telefunken to fulfil the
same purpose as the Jagdschloss Michael B using the so-called
Euklid 25-29 cm. waveband employed by the Navy. Once more a
very long aerial array 48 metres long and about 8 metres high
was used, employing a cylindrical paraboloid. A wave guide
antenna (Hohlraumstrahler) was placed along the focal line
with a second and a third wave guide parallel to it above and
below respectively. The object of these two supplementary wave
guide aerials was to provide displaced beams and so avoid the
dead zones. A range of 220 km. was expected against single
aircraft but no details were available as to whether it had
come into operational use.

Forsthaus KF.
112. In order to introduce as rapidly as possible a panoramic
early-warning radar in the West on a hitherto unused
wavelength, a smaller form of the Forsthaus F called the KF
was to be introduced while the F was being completed. It was
planned so that it could be used on a railway wagon; the
revolving aerial array was only 24 metres long and it was
expected to give a range of 120 km. The wavelength and
electrical circuits used were exactly the same as in the

Forsthaus F.
Dreh Freya.
113. This set, which was also known as Freya Panorama, was
first introduced in June 1944. It consisted of a Freya aerial
of the Breitband type working in Bereich I (1.90-2.50), the
frequency of which could be adjusted at will. The aerial was
so built that it rotated through 360° and gave a remote
panoramic presentation. About 20 equipments were in use in
January 1945. The range claimed for it was only about 100 km.

Jagdhütte.
114. This apparatus, which was produced by Siemens, gave a
panoramic P.P.I. display of the German I.F.F. responses, using
24 metre or 36 metre rotating aerials. The wavelength employed
was 2.40 metres and it was planned, with its aid, to trigger
off the FuGe 25A. In this way friendly fighters were to be
controlled from the ground at ranges up to about 300 km. It
was fully realised that if the FuGe 25A frequency was ever
jammed the Jagdhütte would be useless, but it was not
considered likely that the Allies would attempt to jam it.
115. On the 1st January 1945 the first Jagdhütte equipment
was being erected, and it was expected that production would
amount to two per month thereafter. At the end of the war
about 8-10 were being built, but there is no information as to
how successfully they were employed.

Jagdwagen.
116. Jagdwagen was designed as a mobile Panoramic radar to
control fighterAs at close ranges immediately behind the front.
It was a project of the firm of Lorenz. The aerials were
considerably smaller than the Jagdhütte, the array being only
8 metres long. The aerial array was to be mounted on the
Kumbach stand as used in the Egerland Flak set. The frequency
bend used was that of the A.S.V. set Hohentwiel namely 53-59
cm.
117. The horizontal beaming was of the same order as that in
the full Jagdschloss F, namely about 6°, and ranges claimed
for it were of the order of 40-60 km. for medium heights. A
small P.P.I. tube of about 15 cm. diameter was used.
118. In February 1945 the first sets were being tried out at
Werneuchen but it was hoped to produce the Jagdwagen, in
series, as a fully mobile panoramic set operated by a
motorised company to install them on aerodromes so that a
picture of the local air position could easily be obtained.

Jagdschloss Z.
114. The Jagdschloss Z was the centimetric form of
Jagdschloss, which was in development by Siemens; the rotating
aerials were to be about 24 metres long. These sets were to
give an extremely narrow beam and so offer protection against
jamming. The range expected was of the order of 100 km., and
although the first experimental equipment had been built it
was not expected that sets would came into operational use
until the autumn of 1945.

Forsthaus Z.
120. The Forsthaus Z was another form of 9 cm. panoramic for
early warning, which was produced by the firm of Telefunken.
It differed from Jagdschloss Z mainly in the design of aerials
and was about in the same stage of production. No information
could be given as to the advantages or disadvantage possessed
by Jagdschloss Z.
NOTE: One of the documents brought to England by General
MARTINI’s staff contained a list of the frequency
coverages mentioned in this report, and is reproduced
in Appendix II."

[Bruce Dennis]

"SECRET A. D. I. (K) Report No. 380/1945
THE FOLLOWING INFORMATION HAS BEEN OBTAINED FROM P/W
AS THE STATEMENTS HAVE NOT AS YET BEEN VERIFIED, NO
MENTION OF THEM SHOULD BE MADE IN INTELLIGENCE
SUMMARIES OF COMMANDS OR LOWER FORMATIONS, NOR SHOULD
THEY BE ACCEPTED UNTIL COMMENTED ON AIR MINISTRY
INTELLIGENCE SUMMARIES OR SPECIAL COMMUNICATIONS.

RADIO AND RADAR EQUIPMENT IN THE LUFTWAFFE – IX.

German Radio Countermeasures.
1. This report is the ninth of the series dealing with
radio and radar equipment in the Luftwaffe. The present
information was mainly obtained from Dr. Ingenieur SCHOLZ, a
civilian employee of the Reichspost Zentrale who was in
charge of a sub-section of Abteilung 6 of the
Generalnachrichtenführer dealing with the problem of RCM
(radio countermeasures).
2. Interrogation of this man has been supported by
information gained from other members of General MARTINI's
staff and by a number of relevant documents of recent date in
possession of the General's Chief of Staff. Some useful
additional help was given by two engineers who had recently
been engaged in testing ground and airborne jamming equipment
at the G.A.F. research establishment at Werneuchen.
3. The radio countermeasures used by the Germans have been
treated in this report under four headings, the first being a
brief historical account of their employment, and the other
three dealing in turn with RCM against communications, metric
radar and centimetre radar. The types of jamming transmitters
referred to by name, or of which a mention has been found in
documents, are listed in alphabetical order and their
functions briefly described in Appendix I to this report.

THE GERMAN MONITORING SERVICE AND EVOLUTION OF COUNTERMEASURES.
BASIS FOR COUNTERMEASURES.
4. At the beginning of the war the G.A.F. High Command was
not radio minded; GOERING in particular has been frequently
accused by his underlings of paying no attention to technical
matters. In the opinion of General MARTINI's staff, the vital
importance of radio warfare and radio countermeasures was
only truly appreciated by the General Staff towards the end
of 1944. Those responsible for German jamming, therefore, had
great difficulty in obtaining permission to use the
countermeasures to the extent that they could have wished.
5. The countermeasure organisation relied in the first
place on the German "Y" service, which formed Abteilung 3 of
General MARTINI's staff, to give advance information of new
radio activities, and for this purpose it employed a staff of
expert radio engineers whose task was to identify and explain
any new frequencies or types of transmissions received. If,
however, novel features in a monitored transmission were
observed and could not be explained, a commission for the
investigation of the particular subject was set up. This
commission was composed of representatives of the "Y" service
and of the Development (E) departments of the R.L.M.,
representatives of the research (F) department of the R.L.M.,
and such experts from the leading firms as had special
experience in the field of radio which was thought to be in
question.
6. Evidence collected by listening, though it could be very
valuable as intelligence, did not necessarily tell the whole
story or indicate the most suitable form of countermeasures.
As far as airborne equipment was concerned, statements made
by prisoners of war often helped to fill out the details and
the capture of equipment and its identification with the new
transmission was of great value, even if the equipment was
severely damaged.
7. Intelligence information from the above three sources
could usually be pieced together to tell the whole story, so
that decisions could be taken as to whether radio
countermeasures were required.
8. The Germans relied very largely on the laboratories and
experience of the Reichspost Zentrale (RPZ) to solve the
technical problem of how and with what equipment to jam, and
they obtained for the duration of the war the loan of an
engineer of that organisation (the present P/W) who was put in
charge of RCM and carried out liaison with RPZ to this end.

EVOLUTION OF COUNTERMEASURES.
9. The decision to jam a particular type of transmission
rested very largely with General MARTINI and was often taken
despite the protests of the "Y" service section of his staff,
who were interested professionally in monitoring all
transmissions. Particularly in the case of R/T, the "Y"
service insisted that more strategic and tactical information
could be obtained by D/F’ing enemy transmissions than any
tactical advantage which might be gained by jamming them.
10. As an instance of the extent to which the decision lay
with General MARTINI the following case was quoted: In 1942
Allied night fighters were becoming a nuisance in the
Mediterranean area but General KESSELRING had to ask General
MARTINI’s permission to jam their ground-to-air R/T control in
his theatre of operations and only then could the
countermeasures be undertaken.
11. The first German radio countermeasures were instituted in
September 1940 during the day bombing raids of the Battle of
Britain and were directed against British radar operations in
the Channel. The first and most important site used was that
at Mont Couple behind Calais were, by the end of the war, a
battery of some 35 jammers had been set up.
12. Radio countermeasures against Gee were put in hand in the
summer of 1942 and at about this same time the first attempts
were made to jam A.S.V. in the Channel. From this time on, the
countermeasure warfare increased and consideration was given
to jamming all types of new radar devices.
13. In about 1943 it was realised that countermeasures might
well be called for on every wavelength, and Dr. SCHOLZ put up
a requirement to the Reichspost Zentrale (RPZ) laboratories
for a series of jammers to be designed for covering all
wavelengths from 50 cm. upwards. These jamming transmitters
were designed in the Potsdam RPZ laboratories, and
improvements were constantly being incorporated in them so
that if there was a sudden call for countermeasures on an as
yet unused frequency, a practical design was available and
apparatus could be built at short notice.
14. As a result of this policy new countermeasures could be
put in hands quickly, but in practice they usually took
considerably longer to organise than might theoretically be
expected because the ground crews had to be trained in their
use. Dr. SCHOLZ stated that with a few exceptions these ground
crews were of second-rate material and it was frequently a
matter of weeks before they were sufficiently well-trained for
the countermeasures to become effective.

COUNTERMEASURES AGAINST COMMUNICATIONS.
GROUND-TO-GROUND COMMUNICATIONS.
15. With the possible exception of communications between land
and convoys, P/W believed that no attempt was made to jam
Allied W/T communications on the ground. Listening to them was
considered to be of the greatest strategic intelligence value
and little or no tactical object was served by jamming.
16. Radio countermeasures against the B.B.C. news service were
in the hands of civilian authorities, and the G.A.F. had
nothing whatsoever to do with them. Dr. MEINEL of the
Reichspost was believed to have been responsible for the
production of the type of jamming modulation which was
generally used.

GROUND-TO-AIR R/T.
17. The question of jamming Allied ground-to-air and air-toair
R/T was one of the points most strongly disputed between
the "Y"-service and the operational side of the G.A.F. The
"Y"-service maintained that by listening to and D/F’ing
traffic, both strategic and tactical intelligence was obtained
and that it was frequently their best source of early warning
of attack by aircraft; as a result relatively few attempts
were made to jam Allied R/T.
18. In the case of German raids on England the signals staff
agreed that there was an advantage in jamming British R/T
communications; this point arose when the possibilities of
Mark IV A.I. were first realised early in 1941. The question
of how to undertake countermeasures against British A.I. was
discussed and the weak point of the system was held to be the
R/T link from ground to air, because it appeared to be
essential for the night fighter to be brought within
2 km. of the bomber before contact could be made.
19. The Reichspost Zentrale built an airborne R/T jammer set
which was given the name of Karuso and was intended to prevent
R/T being heard by the night fighter when the latter was
within 3 km of its target. Within eight weeks the first Karuso
equipment was ready and a total of 100 were built. With the
cessation of the bombing of England in about May 1941, the
majority arrived too late and Karuso was only used once in a
limited number of aircraft in a bombing operation when, P/W
believed, Plymouth was the target.
20. When in 1943 trouble with British night fighters was again
being experienced in the Mediterranean, the Karuso sets were
sent down to that theatre. There, however, the range of
British A.I. was found to be about 4 km. instead of 2 km., so
that the power output of Karuso had to be boosted to give it a
range of 5 km.
21. The method employed was barrage jamming using two bands
(100 - 110 mc/s and 110 - 120 mc/s) with mechanical condensertuned
sweep through the band. There was not room for two
transmitters in one aircraft so only half the band could be
covered in any one German bomber. Karuso III, a later
improvement, was to be capable of being tuned through 100 -
150 mc/s band but so far as is known, it was not put into use.
22. Subsequent tests of Karuso indicated that it had
insufficient range, and by December 1944 the Starnberg, which
was developed in 1940 by D.V.L. as a jammer against radar, had
also been tried out but was likewise considered inefficient. A
new set named Nervtöter was under development but never came
into operational use.
23. It was decided that the jamming of R/T would be of value
against air activity when the invasion took place and prior to
D-Day some 50 or 60 modified Karl II jammers had been formed
into a Stördorf (= jamming village) and assembled at a site on
the Channel coast near Dieppe. With this assembly of jammers,
all possible frequencies in the 100 - 150 mc/s R/T band could
be covered.
24. A few days before the invasion the site was carpet bombed
by the Americans and although the jammers had been somewhat
dispersed, 90 of them had their aerials damaged or were put
out of action. There was some delay in bringing up reserve
motorised units and the invasion took place before they
reached the Channel coast. As a result, no countermeasures
against fighter R/T took place during the invasion.
25. In November 1944 a limited amount of jamming of fighter
R/T in the 70 - 100 mc/s band was carried out on the western
front by motorised units and from a few fixed sites. These
countermeasures were on a restricted scale, owing to lack of
apparatus, but it was hoped to interfere with Allied ground
control of fighters and fighter R/T.

AIR-TO-AIR R/T.
26. During defensive operations over the Reich against Allied
aircraft, countermeasures were very rarely used owing to the
insistence of the "Y"-service on the value of D/F’ing
transmissions, particularly as the German early warning radar
was heavily jammed. Early in 1945, however, it was planned to
create four jamming villages (Stördorf) each with ten Karl
transmitters in order to jam R/T during raids over German
territory. The use of airborne jammers to carry out the same
task had been considered but it was felt that airborne jamming
was less rational than jamming from ground stations because
the frequencies had to be constantly monitored.
27. By the end of the war a new jamming transmitter called the
Feuerland had been developed by Blaupunkt. This allowed noise
modulation to be used in addition to the more generally used
Reichspost modulation. A few sets were sent up to the Holstein
area just before the capitulation, but it was believed that
they had never been used in operations.
28. The standard type of modulation which had been developed
by Reichspost consisted of a number of "Kipp" frequencies -
sharp triangular pulses produced by blocking oscillators -
superimposed on the carrier wave. Tests of its effectiveness
at audio frequencies were carried out early in the war and a
statistical analysis of them seemed to show that it was the
most effective modulation against R/T.

RUSSIAN R/T
29. The airborne FuGe.10 was being developed for use as a
jamming transmitter against the 3 - 6 mc/s band R/T used by
the Russian Air Force. This apparatus never came into
operational use.

R.C.M. AGAINST METRIC RADAR
EARLY WARNING RADAR
30. It was in August or September 1940 during the Battle of
Britain that the first German countermeasures were directed
against British ground radar. The site at Mont Couple behind
Calais was used at first, but was gradually extended to a
chain of ground jammers along the whole Channel coast, and
ultimately there were sufficient to have every identified
British ground radar station covered by at least one suitable
jammer.
31. In 1940 the stations jammed were those in the 20 - 30 mc/s
and 50 – 90 mc/s bands. Both ground stations and airborne
apparatus carried in Ju.52's were used. By 1941 a chain of
Karl jammers which also covered the 200 mc/s band had been set
up along the whole coast.
32. During the initial period, various efforts were made to
spoof our early warning radar. The first of these was the
brain-child of Dr. SCHOLZ and was tried out in 1940.
33. Pulses radiated by one of our C.H. stations were picked up
on the ground and re-transmitted on a different frequency to
an aircraft flying some way behind the Channel coast. The
aircraft re-transmitted the original radar pulse on the C.H.
frequency, but a slightly different phasing, so that a phoney
blip located over the Channel was received. Owing to the ease
with which this phoney blip could be D/F'd and the spoof
immediately revealed by a second station, this method was soon
discarded.
34. About the beginning of 1941 a special experimental
equipment called the Garmisch Partenkirchen, which produced no
less than five different phasings and five phony blips, was
tried out. For the same reason this was not much used in
practice.

How the "S & G" Got Through.
35. The first big operation on which the jamming chain against
British radar ground stations was used was on the occasion of
the passage through the Channel of the Scharnhorst and
Gneisenau in February 1942. A few days prior to the operation
Dr. SCHOLZ was specially brought from Berlin to supervise it.
36. The radar cover of our C.H. and C.H.L. had been carefully
plotted and it was ascertained that the ships would come
within its range as they passed off Fecamp, where they were
due at 10 a.m. At that hour every available jammer was
switched on. The fact that the ships passed through unscathed
was, in P/W's opinion, the best proof of the effectiveness of
the German countermeasures. P/W was not aware that we had
either decimetre or centimetre radar in operation at this
time.

Siege of Malta.
37. In July 1942 P/W was sent to Sicily to take charge of an
intensive jamming programme which he suspected was to be the
precursor of the invasion of Malta, although he was never told
so officially. The first four Karl jammers on 193 mc/s were
brought into service in the neighbourhood of Noto en 3rd July
1942 and the number was later increased to eight, to cover
both A.I. and ground stations. They were beamed on to the
sites at Malta. These transmitters were half kilowatt, C.W.
amplitude-modulated at 100 c.p.s. using an unsmoothed HT
supply, plus a modulation of 150 - 200 kc/s. The reason for
the amplitude modulation being unsmoothed was that there was a
shortage of high-voltage smoothing condensers.
38. After a time it was observed that we had adopted frequency
changes. The German jammers were however, controlled by
monitoring receivers on sites so arranged that the jamming
signals and the original radar signals could be seen side by
side on a C.R. tube; this enabled the frequency change to be
followed within a few seconds. A great aid to them in
following and preparing for these changes was that new
frequencies were invariably tried out during the day from
Malta and the monitoring service could warn the jamming
operators of frequencies likely to be employed.
39. It was noticed that signals on the 50 - 80 mc/s frequency
were switched on during a raid and it was suspected that they
were due to the height-finding equipment of the radar station
controlling our night fighter which seemed to operate in a
similar fashion to the German Würzburg. This opinion was
confirmed when "Y" service heard a ground station say that
they could give the range of the bandits but that height
measurements were not yet available.
40. To jam the "height-finding" frequencies a Ju.52 fitted
with eight jammers covering the 50 - 80 mc/s band was brought
down to Catania. An hour before a raiding force became
airborne this aircraft left Catania to patrol half way between
Sicily and Malta and jam this band.
41. After P/W left, jamming was also carried out on the 42
mc/s band with the same type of Karl ground transmitter as was
used for other frequencies.
Modulation of Jammers.
42. When jamming out ground radar, H.F. modulation was always
preferred to noise modulation since the equipment necessary to
produce a given effect with noise modulation was much more
extensive than for H.F. modulation, and in particular a large
number of high-power valves was needed. The greater efficiency
of noise modulation was not considered sufficient to warrant
the extra power and extra equipment needed. It was also
thought unlikely that H.F. modulation could be filtered out of
the radar receiver without severe deterioration of the
picture.

Düppel (Window).
43. The idea of using window to spoof ground radar had
occurred to the Germans in 1941 and a series of experiments
was carried out in great secrecy over the Baltic in February
1943 (See A.D.I.(K) 334/1945 Part, IV). Very careful
arrangements were made to ensure that the wind was in the
right direction so that the window strips would fall into the
sea and not in Sweden, or even on German occupied territory.
44. The effect of window was observed on all types of German
ground radar deployed along the Baltic coast, and its efficacy
as a countermeasure was realised. The German codename for
Window was "Düppel" - a word with a very similar pronunciation
to the German word "Dipol" (= dipole), indicating the function
of the metal strips.
45. The Signals Staff realised that Düppel was a two edge
weapon and although its development was completed sometime in
1942, and a certain quantity was manufactured, no use was made
of it for fear of Allied retaliation.
46. The whole project was, in fact, kept so secret, that only
a very few high officers and technical experts in the G.A.F.
were aware of the scheme. So closely was the secret of Düppel
guarded that the scientists were not even allowed to carry out
research work to discover what anti-window measures could be
applied to the various types of German radar.
47. Although the Germans were free to employ window as a
countermeasure over this country after its first use by the
R.A.F.in July 1943, it was realised by the Signals Staff that
they had never used it to such good effect as the Allies.
48. The reason was that the small German bomber aircraft like
the Ju.88 could only carry a very limited quantity and
therefore could not produce a real window cloud. They
therefore decided to drop small quantities scattered over a
wide area in the hope of deceiving the night fighters and of
producing the impression that a larger number of aircraft was
engaged on a certain raid as well as in the hope that ground
controllers might vector night fighters on to a window cloud
instead of on to an aircraft.

Final Policy against Early Warning Radar.
49. The general policy followed by the G.A.F. at the end of
the war with regard to the countermeasures against early
warning metric radar appear to be summarised in a document
dated December 1944, which states that the use of ground
jammers against all ground radar is, in principle,
particularly desirable during German bomber raids on enemy
territory, but that there is no advantage in using airborne
jammers because the frequency of the ground radar has to be
constantly monitored and followed.
50. This principle was not strictly adhered to because an
airborne jammer for the 170 - 220 mc/s band named Kettenhund
was used to a small extent in raids on the South-West of
England in May 1944 (sec A.D.I.(K) 321/1944) but it was not
considered to be very effective.
51. Some attempt was being made to develop a noise-modulated
airborne transmitter named Wolke but it was never used
operationally.

METRIC A.S.V.
52. The first attempts to jam A.S.V. were made in the Channel
in the summer of 1942. During the preparations for the
proposed invasion of Malta it was found that reception of
British A.S.V. transmissions was obtained at extraordinary
ranges in the Mediterranean area. This was ascribed largely to
the fact that the receivers were placed as high as possible -
in some cases 3,000 foot above sea level - and attempts were
made to jam A.S.V. by using Karl transmitters placed near them
on high points of the coast of Sicily, Greece and Crete.
53. At about this time a Sonderkommando KOCH was formed and
based at Athens-Kalamaki. Its duties were to monitor and jam
A.S.V. and it was thought they used the Kobold airborne
transmitter with a frequency range of 160 - 200 mc/s. It had
the disadvantage that it could only be built into large
aircraft and some doubts arose as to whether it was very
effective.
54. Up to the of the war, the Bari ground jammers continued to
be employed against A.S.V., particularly along the length of
the Adriatic and along the Norwegian coast at points where
German coastal convoys obtained no cover from islands lying
off the coast.
55. In mid-1943 U-boats leaving Brest were suffering a serious
increase in losses owing, it was thought, to the use of our
A.S.V. a Sonderkommando Rastädter was formed with a few He.111
and Ju.88 aircraft for the purpose of listening to British
A.S.V. on metric and centimetric wavelengths and determining
what type of radar was being used with such effect (see
A.D.I.(K) 38/1944). These aircraft carried, amongst other
receivers, both Naxos and Korfu. The net conclusion reached as
a result of these investigations was that Coastal Command was
using a centimetric frequency (presumably H2S) for which the
Germans had no jamming transmitter.
56. The Allied attacks on U-boats took place so far from the
coast that ground jamming of A.S.V. on metric wavelength was
impossible and too many aircraft were needed to carry out
efficient airborne jamming. It was feared, too, that if
airborne jamming were carried cut, it would only attract
A.S.V.-equipped aircraft or surface vessels to the vicinity,
and be a proof that U-boats were about.
57. Warning receivers were therefore installed in U-boats. The
first of these - Metox - was used against metric A.S.V. It
suffered from the disadvantage that its local oscillator
radiated strongly, and it was suspected that we could home on
to this radiation from 100 km.; the Samos receiver later
replaced Metox. A form of Naxos was introduced to provide
warning against 9 cm. A.S.V. and was used up to the end of the
war.

METRIC A.I.
58. The weak link in the British night fighter organisation
was, as already mentioned, considered to be the R/T
communication; the airborne jamming of British A.I. itself by
German bombers or special R.C.M. aircraft was not considered a
practical measure because it was believed that British night
fighters would be able to home on to the jamming aircraft and
severe losses were therefore to be expected.
59. No intentional jamming of Mark IV A.I. was ever carried
out from the air or from the ground, although it was
considered possible that Karl jammers against G.C.I. and
harmonics of the Heinrich transmitter against Gee, and
possibly of all transmitters jamming Oboe and C.H., may have
had some effect.
60. In this connection P/W stated that it was extremely
convenient for the Germans that we had so many equipment
working on such a restricted frequency band in the 200 mc/s
region. This fact has eased their jamming problem very
considerably.

GEE.
61. The value of Gee system of navigation referred to by the
Germans as Hyperbel, is that it allows an aircraft to navigate
by a radar method without transmitting any signals which could
be used to D/F the raider from the ground. This threat was
realised by the Germans in March 1942 when the existence and
method of operation of the system was first discovered, but
the decision to jam Gee was not taken until August 1942.
62. A jamming transmitter was hurriedly improvised out of the
standard A.S. ground transmitter used for R/T traffic with the
FuGe.16. This was modulated with the standard "Mont Couple"
modulation at 150 - 200 kc/s. Prior to this makeshift coming
into use, a certain Dr. MÖGEL had experimented locally with
jamming transmitters but these only operated for a short time
and no details are known of them.
63. An order for a large number of suitable jamming
transmitters for countering Gee was placed in August 1942 and
the first of these - 1/2kw. Heinrich - went into service in
November 1942. As the Heinrich transmitters became available
in quantity they were deployed all over Germany and by the end
of the war some 270 were in operation against Gee.
64. Estimates of the effectiveness of jamming by the deployed
Heinrich transmitters were obtained by flying captured Gee
equipment and by questioning British P/W. The conclusion
reached was that before the invasion the Gee chains were of no
use further East than 4°.
65. After the invasion the situation changed, and in August
1944 a so-called Stördorf (= jamming village) was set up on
the Feldberg in the Taunus area and controlled and run by the
Reichspost Zentrale. Installation began in August and in
September the first equipment came into use.
66. The Gee countermeasures from the Feldberg site were of a
different type. In addition to a number of normal Heinrich
transmitters, three new types of much greater power were used.
These were Feuerzange, a very powerful pulse transmitter with
a peak power of 1 megawatt, Feuerstein with a peak power of
120 kw. at 5,000 pulses and a smaller transmitter, Feuerhilfe
with a power of 30 kw. which had been improvised by Köthen.
These three powerful transmitters were used to pick up the Gee
transmissions and retransmit them but with a very slightly
different p.r.f. A keying arrangement was incorporated so that
the pulses of the master and slave stations could be imitated.
67. In the immediate neighbourhood of the site it was expected
that the pulse powers used would be so high that the Gee
presentation screen would be completely jammed. At greater
distances aircraft would receive on each frequency used three
or four false pictures broadcast by the Feuerzange and
Feuerstein. As they transmittal their spoof pictures on
p.r.f's which differed only slightly from that used by the
British stations, the effect produced was that the false
pictures wandered very slowly over the true pictures so that
it was difficult for an operator to tell which was the correct
set of blips.
68. At the beginning an insufficient number of sets was
available to carry out this spoofing on all the chains, but by
January 1945 the site was fully equipped. The Germans were
convinced that this system was successful because on 2nd March
1945 at 1230 p.m. a number of fighter bombers paid them a very
unwelcome, visit and completely destroyed the site.
69. Consideration given to the idea of jamming the link
between the Gee ground stations, was never carried out as it
was thought that we would certainly anticipated such measures
by providing a number of reserve links, possibly on centimetre
wavelengths, or oven co-axial cable links.
70. When Gee jamming was first properly undertaken towards the
end of 1942, a large number of monitoring stations placed
about 100 km. apart were erected around the occupied coast
form Brest to Norway. Each site had two Heinrich transmitting
units, one operational and one spare, and monitored all
possible wavelengths. Changes of phase were also reported so
that German aircraft flying with Gee equipment could be
notified by W/T.
71. The whole problem of Gee jamming was considerably
simplified on the few occasions that we made unexpected
frequency changes, because our transmitters lined up on the
new frequency before they were used operationally. Had this
not been done the effectiveness of the German jamming program,
might have been considerably reduced.

LORAN.
72. As has been mentioned in a previous report of this series,
the discovery of Loran came as a great shock to the Germans
because Professor von HANDEL had convinced himself that a
long-range, comparatively long-wave pulse system would be too
inaccurate for employment as a means of navigation. The
Germans' first knowledge of the system was obtained about the
middle of 1944 when maps were captured, and ultimately a
complete apparatus was obtained from an American aircraft.
73. Attempts were made to jam it, and by March 1945, 10 to 20
one kW noise jammers, which jammed the ground wave
satisfactorily within a radius of 50 to 100 km., were in
operation. At this time transmitters to meacon the pulses were
being built and consideration had been given to jamming the
synchronisation of the transmitters from the ground, using a
100 kW. C.W. transmitter which was to be erected as near the
front line as possible in order to be near the ground link.
74. The transmitter was ready and hat been taken to Thüringen
but the disruption of transport and communications prevented
it ever being used operationally.

G.II.
75. The same equipment was used for jamming G.H., known to the
Germans as Diskus, as was used for jamming Gee.
76. A number of jamming villages (Stördörfer) with from two to
eight Heinrich transmitters were deployed throughout Germany.
It was calculated in December 1944 that at 20,000 feet G.H.
could only be received and used up to a line joining Emden and
Kassel and from there swinging South in an arc to Stuttgart,
while at 33,000 feet reception was thought to be possible up
to an arc joining the mouth of the Elbe, Weimar and Augsburg.
77. In addition, it was planned to use the powerful Feuerzange
and Feuerstein transmitters in an attempt to trigger-off the
ground stations from the Feldberg/Taunus Stördorf used to jam
the Gee chains.

OBOE - METRIC WAVELENG.
78. In the autumn of 1942 a new type of radar signal in the
200 mc/s band was picked up by the German monitoring service
at Calais. Statistics were kept and it was observed that these
transmissions occurred mainly at night, and seemed to be
associated with British M.T.B. activity in the Channel.
79. In about June 1943 the same type of radar signals was
heard in Essen during a very heavy bomber raid on Cologne and
Dr. SCHOLZ was able to correlate them with the dropping of
T.I's visually observed. It was realised at once that these
signals were the same as those heard at Calais and an
immediate investigation was carried out. For this purpose a
"noise investigation commission" was formed and a special
experimental Freya with a number of D/F receivers was set up.
The Freya was used to plot the course of the T.I.-carrying
aircraft while the receivers D/F'd and monitored the signals.
80. Some 6 to 8 weeks after the signals had first been
attributed to path-finders, a satisfactory story had been
worked out by the Germans as to how Oboe, called by them
Bumerang, worked. When this had been accomplished, subsequent
Oboe raids were systematically monitored by the normal
monitoring service.
81. At this time (August 1943) plenty of jammers were
available because of the reserve apparatus available for use
against 200 mc/s radar stations on the Channel coast. Ten
sites were chosen to give jamming coverage over the Ruhr and
eight ½ KW MCW Karl jammers employed at each site. The
standard Mont Couple modulation also used against C.H.L.
stations was applied giving 150 mc/s sine wave modulation at
100 c.p.s from an unsmoothed H.T. line.
82. The radio frequency was determined by picking up the
aircraft return signal and tuning the jamming transmitter
until the normal signal failed. Four frequencies in the 200
mc/s band were ultimately detected, but though the ground
station frequencies were found to be steady, those of the
airborne transmitter were not very stable.
83. Aerials recovered from crashes appeared to be mounted
sometimes en the starboard wing and sometimes on the port wing
of the aircraft. This fact, combined with some information
obtained from a British P/W, caused the Germans to believe
that the aerials were directional, and in order to jam more
successfully, all transmitters were moved to the West of the
Ruhr.
84. Jamming was almost entirely confined to the Ruhr area
because this territory was far away, the most important target
within the limited range of Oboe. The Germans were greatly
relieved when Oboe was used against the rocket sites in
Northern France, as the pressure on the industrial Ruhr was
thereby reduced. From about December 1943, intermittent
attempts were made to jam Oboe ground stations from the site
at Mont Couple behind Calais. These were not very successful -
a fact which was attributed to the beam width of British
aerials.
85. In June 1944 a new form of jamming which was known as the
Ballverfahren was suggested. This was essentially meaconing,
using an A.B.G. responding transmitter in the hope of
confusing the aircraft's return signals to the ground station.
It was believed to work well, and P/W quoted as an example a
raid on Nürnberg when aircraft deviated from their course as
soon as the jamming was switched on and returned to their
course when it lifted.
86. An instance of the success of Oboe jamming on the Ball
system was quoted. In June 1944 an oil installation - possibly
Wanne-Eickel - was the target, and all Oboe aircraft were
successfully jammed. The T.I's were dropped late and some 8 km
away from the target. As a result of this the main bomber
force spread out and many aircraft were shot down.
87. Only one metric Oboe receiver fell into German hands and
that was 90% destroyed; although the Germans knew the
principle, therefore, the details of the airborne set were
lacking, and the effectiveness of jamming could only be judged
by the accuracy of bombing.
88. By observing on a Freya the point at which bombs left the
aircraft, the Germans estimated the accuracy of Oboe as 300 x
300 metres for bombing from 9,000 metres, but a further 200
metres of ballistic inaccuracy occurred, giving an effective
error of 500 x 500 metres in the Ruhr area.
89. The success of jamming Oboe was considered to depend
partly on the training of personnel, so it was less effective
on a new target than on an old target which had been jammed
before. It was finally believed that the jamming was 90%
effective.
90. The Germans claim to have been so familiar with Oboe that
they were able to plot aircraft and withhold their jamming
until the aircraft turned onto the bombing run. They were then
able to identify the real target and localise the air-raid
warnings so as to disturb industrial production in the
neighbourhood as little as possible.
91. It is of some interest that on several occasions there was
a consistently good concentration of bombs in an open field
near Leverkusen, which P/W presumed to be due to an error in
computing the exact location of the target.

COUNTERMEASURES AGAINST RADAR.
OBOE - CENTIMETRE WAVELENGTHS.
92. Signals which were recognised as Oboe by the type of
coding were detected on a wavelength of 9 cm on the Channel
coast about the spring of 1944. The normal monitoring service
had previously intercepted unexplained 9 cm. signals in
October 1943 but had not finally connected them with Oboe.
93. When 9 cm. Oboe was recognised, it presented the Germans
with a great problem, as no jamming valves were available for
that frequency and German intelligence had not given any hint
that a centimetre version of Oboe might be produced.
94. By July 1944 a valve called LD.7o (= 7 ohne = without) had
been produced, which was an LD.7 valve without cooling fins. A
transmitter unit called Feuermolch, tuneable from 8.6 - 9.6
cm., pulse modulated and giving 3 kW peak pulse power, was
than built. The whole apparatus, a Feuermolch transmitter
together with a mirror reflector to achieve 200 km. range by
beaming, was called Feuerball or A.B.G. (Anti Bumerang Gerät).
95. Jamming on 9 cm. Oboe was first used in operations in
October 1944 at Weser and Leuna. The Feuerball jammer was used
as a pulse repeater, after the frequency had been established
by interrogating the aircraft. The jammer then set up ringing
between the aircraft and jammer on the Ball system used
against metric Oboe.
96. The latest type of centimetric meacon responder called
Feuerburg had receiver and transmitter aerial mechanically
linked to follow individual aircraft, the jammer aerial system
giving a beam of 13° width. The aircraft was followed by hand
by means of a spinning dipole in a receiving dish.
97. According to Dr. SCHOLZ the wavelength originally used by
British centimetric Oboe was 9.26 cm. Sites were set up with
both 200 mc/s and 9 cm. jammers so that either could be
selected by a change-over switch on the receivers.
98. The jamming of Oboe by spoof massages was never tried
although the meaconing jammers were fitted with a keying
arrangement which would have allowed them to attempt this.
99. Oberleutnant Dr. BÄHRE of Ln. Versuchs Regt. Köthen had
doubts as to the effectiveness of the Ball system and had
proposed building a jammer with a very high p.r.f. to saturate
the aircraft receiver with pulses so that the strength of each
individual pulse re-radiated by the aircraft transmitter would
be greatly reduced and the range of the system would therefore
be considerably decreased. The Roland J transmitter which had
been designed for H2S countermeasures was to be adapted by
Lorenz for this purpose, but the idea was never put into
operation as the end of hostilities occurred shortly after it
was made.
100. An example of the success of jamming centimetric Oboe was
quoted and concerned a series of five raids on Gotha. Three
attacks, each with between three and five aircraft, were
unjammed and all scored hits on the railway station. The
fourth attack was jammed and no hits were scored on the same
target. The fifth attack was again let pass without jamming
and the station was once more successfully hit.
101. A further proof of the efficiency of the Ball system was
that in plotting aircraft a diversion from track could be
induced when the jammer was switched on and the aircraft would
return to track if the jammer were switched off again.
102. On the only occasion on which a 9 cm. Oboe aircraft was
known to have been shot down, it crashed in the Zuider Zee in
shallow water where it could neither be reached from shore nor
by sizable ship, and it was not possible to salvage the
equipment. As a result, the Germans never obtained any Mark II
Oboe equipment and detailed information as to how the system
worked was always lacking. There was no explanation, for
instance, of why certain aircraft transmitted pulses which did
not appear to have normal Oboe coding, although the aircraft
flow at heights and along tracks which obviously identified
them with Oboe procedure.
103. No advance information of the target could be obtained
from these aircraft but this was easily obtained from the W/T
transmissions between ground stations. The W/T channel used
was also monitored in order to see if jamming had been
successful. It was also noticed that some aircraft would not
respond to the interrogator but the reasons for this were not
fully understood. These aircraft seemed to be operating on a
wavelength above 9.6 cm.
104. A new valve to cover the 9.6 - 10.6 cm. band was being
produced by Dr. GROOS. It was a 100-watt Klystron and it was
proposed to jam with its aid as soon as it was finally
produced.
105. Towards the end of the war there was a great increase in
the daylight use of Oboe but P/W did not believe that the
Americans had ever used it. With so many aircraft over Germany
towards the end of the war correlated evidence was not
available.

H2S.
106. Shortly after the discovery of H2S in January 1943 panic
orders were given for the production of a jammer. Later in the
year Roderich, which was manufactured by Siemens and which
used a Magnetron of theoretically 5-watt power, was made
available. The transmitters were unbeamed and the power was so
low that they were useless. By 1944 the use of Roderich had
been discontinued.
107. The difficulties of jamming highly-beamed centimetric
radar were so great that it was decided that all that could be
done was to attempt to defend a few vital targets. The first
target to be chosen was the Leuna works which was considered a
good target.
108. The Reichspost Zentrale was called on for assistance and
Dr. GROOS of that institution successfully developed a
Klystron valve, which was a water cooled 100-watt valve
tuneable by hand from 8.5 - 9.5 cm. This was built into the
jamming transmitter which was known as the Postklystron.
109. In order to concentrate as much of the energy as possible
to the aircraft, horns or paraboloid aerial reflectors were
employed with the transmitters. About eight sites around Leuna
were chosen, bearing in mind that the attacks always seemed to
use a route coming in from the North, presumably because the
best H2S pinpoints lay in this direction.
110. Four Postklystron transmitters were placed on suitable
sites and spaced in frequency across the observed 30 mc/s band
of H2S by putting them about 5 mc/s apart and making use of
the side bands from 2 - 10 mc/s single frequency amplitude
modulation. This barrage was used with low directivity.
111. A second type of jammer employed made use of the Roland
transmitter built by Siemens, which had a 30° beam, but its
development was abandoned about March 1945, as it was not
considered very successful.
112. In yet a third system Postklystrons were used with a
beamed aerial system giving a lobe 6° wide. The transmitter
was coupled mechanically to the D/F, receiving aerial of a
Korfu receiver, its aerial being provided with rotational
eccentric split. The receiving aerial was trained on a single
H2S bomber, which was followed manually.
113. The detection range for setting up was about 300 km. With
the less beamed type, Roland, effective jamming ranges up to
about 30 km had been obtained but with the narrow 6° beaming
the H2S tube was completely obliterated at 40 km if the beam
was focussed on the H2S aircraft.
114. One P/W had flown with H2S equipment installed in German
aircraft in order to carry out experiments in ground
camouflage against H2S with the aid of corner reflectors. The
conclusion was that corner reflectors were ineffective. It had
originally been planned to cover arms of the sea and lakes
with corner reflectors, but in the first place too many were
needed, and in the second place arrangements had to be made
for these to remain fixed in a certain orientation in order to
produce an effect.
115. Another suggestion had been made that metallic powder
could be used to increase the reflectivity of an area. This
was obviously no use as camouflage for a target, which was the
end originally in view. Consideration was given to producing a
dummy target with its aid but it was concluded that the
quantity of powder necessary was so enormous that it was not a
practical proposition.

H2X.
116. The Germans had such leeway to make up with the production
of 3 cm valves that no active countermeasures against H2X had
been put in operation up to the end of the war. Development of
a transmitter called Roland 2 was started in December 1944
with Telefunken Ceramic 3 cm valves believed to be known by
the designation LD.72 and LD.77.
117. The set was to be modulated by 100 kc/s pulses and to
sweep through a small radio frequency band. The power achieved
was 50 watts average. With horn aerials a 20° beam was to be
achieved. The range against an H2X set which had been captured
undamaged at Wiesbaden was 20 km. in the initial experiments.

A.I.
118. Owing to the strong beaming and method of sweep of
centimetre A.I. the G.A.F. was doubtful if any jamming would
be possible. No airborne transmitters against centimetric radar
were developed.

-o-o-o-o-o-o-o-o-o-o

ACKNOWLEDGEMENT.
Acknowledgements are due to the various technical bodies,
both British and American, who collaborated in producing the
technical information contained in this report.
A.D.I.(K) and S.D.Felkin,
U.S. Air Interrogation. Group Captain.
29th August, 1945.

A.B.G. (DALL)
The A.B.G.(Anti Bumerang Gerät) meaconing jammer was first
used in June 1944 and was an idea fathered by P/W. It was a
responder beacon which was employed against Oboe to set up
"ringing" between the aircraft return signal and the A.B.G. so
that the aircraft return to the ground station was confused.
The jamming transmitter had a 20 - 30 kW power in the case of
the model used against 200 mc/s Oboe. In the A.B.G. used
against 9 cm. Oboe (Feuerball) the power was 3 kW.

BRESLAU.
This was the pulse modulated transmitter with a range from
20 - 250 mc/s developed and built in the G.A.F. laboratories
in PARIS. It was believed to have consisted of six or eight
½ kW transmitters. Some 50 sets only were put in hand and
about half of them were completed. It was thought that they
had been used against ground radar stations along the Channel
but with what success it was not known.

FEUERBALL.
This was the name for the A.B.G. centimetric responder used to
jam centimetre Oboe. The jammer was used as a pulse repeater
and set up ringing between the aircraft and the jammer. It
consisted of a transmitter using a klystron valve developed by
the R.P.Z. which covered the frequencies 9.0 - 9.6 cm., backed
by a beaming reflector. The peak power was about 3 kW.

FEUERBURG.
In order that the Feuerball transmitter should be beamed on to
the transmitting aircraft, a beamed receiver was mechanically
linked to the Feuerball set. The receiver was operated so that
the receiving mirror was aligned on the aircraft and the
Feuerball paraboloid mirror followed any changes of elevation
or direction made by the receiving operator. This complete
set-up of beamed Korfu receiver with a Feuerball beamed
transmitter was known as Feuerburg.

FEUERHILFE.
This was a smaller form of Feuerstein improvised by Köthen
with a peak pulse power of 30 kW.

FEUERLAND.
This was a two-stage inductive transmitter (final stage
LS.1000) manufactured by Blaupunkt and served the same purpose
as the Karl II. The first production sets were ready in March
1945 and were believed to have been sent to the Holstein area,
but they were never used operationally.
The frequency of the Feuerland could be adjusted from
30 mc/s to 300 mc/s by means of interchangeable H.F. coils.
Different types of modulation could be introduced according to
whether it was to be used against R/T or radar. Against R/T it
was known to have had the four-tone chime modulation described
under Nervtöter below. It could also be used with noise
modulation with an adjustable bandwidth up to 2 mc/s. The
power output was about 350 - 500 watts.

FEUERMOLCH.
This was the name given to the centimetric transmitting
equipment of the Feuerball.

FEUERSTEIN.
The Feuerstein designed by Telefunken was used for producing
a false picture on Gee sets, the keying of the pulses being
carried out by equipment supplied by Telefunken and Siemens. A
number of these sets were installed on the Feldberg. It was a
high-power pulse transmitter at frequency range of either 20 -
52 mc/s (known as the Feuerstein 1) or 48 - 90 mc/s (known as
the Feuerstein la). At a p.r.f. of 5,000 cycles it had a peak
power of 120 kW.

FEUERZANGE.
This was the highest-powered pulse transmitter possessed by
the Germans and was used in 1945 on the Feldberg to provide
spoof Gee transmissions. The transmitter, developed by Dr.
FREUDENHAMMER and built by Siemens, was water-cooled and could
be modulated in exactly the same way as Feuerstein. The
frequency range of the transmitter was 20 - 87.5 mc/s and at a
p.r.f. of 5,000 cycles a power of 1 megawatt was claimed. It
was considered a very effective set but only came into
operation towards the end of 1944.

GARMISCH PARTENKIRCHEN.
Garmisch Partenkirchen was believed to be an improvised
airborne apparatus, probably manufactured by Neufeld and
Kuhnke of Kiel. It was used to a very limited extent in 1941.
It consisted of a receiver which picked up a ground radar
transmission and re-transmitted on the same wavelength but
returned no less than five different pulses with slightly
different phases with the object of creating false echoes. As
these false echoes could be immediately identified if a second
ground radar D/F’d the jamming aircraft, the idea was carried
no further.

GEWITTERZIEGE.
An experimental spark, ground jamming transmitter for
employment against flight radar and using a 1/2 wavelength
dipole aerial in front of a reflector, was given the code name
Gewitterziege. The band width was very large but it was
claimed that it was an effective jammer at close range.

HEINRICH.
This transmitter was developed by the Reichspost Zentrale in
1942 with the specific intention of providing the G.A.F. with
a jammer against the Gee navigation system. A large number of
these sets was built and deployed all over Germany to jam Gee.
A set of the same type, from which Heinrich had been
developed, was used in Sicily in July 1942 for jamming the
radar stations in the 50 - 80 mc/s band in Malta.
In its ultimate form, Heinrich II, the transmitter had a
power of 500 watts and covered the band from 20 - 90 mc/s in
four separate sections. For this output it used four LS.180
valves arranged in parallel push-pull.
It was 100% modulated by 150 kc/s sine wave with the
addition of 100 cycle ripple obtained from an unsmoothed H.T.
power supply. The set needed only two controls, one for the
main tuning and one for the aerial coupling.
The aerial consisted of a wide band dipole of squirrel cage
circular section, with normal tapping at the feeding point.
This one aerial was used in the entire frequency band from 20
– 90 mc/s. It was stated to have a standing wave ratio of 20%
in voltage.

KARL I.
This was the standard jamming transmitter for use against
British radar and was designed to cover the frequencies 90 -
250 mc/s in two bands. Development work on it was started at
the end of 1940. The transmitter employed four LS.180 valves
and had a power output of between 300 and 500 Watts. It was
modulated by the standard Mont Couple 150 kc modulation on
which a 100-cycle tone coming from an unsmoothed 50-cyle
source of supply was imposed. The type of modulation employed
could not be changed in the field.

KARL II.
This was on improvement of Karl I with few changes in the
electrical specifications but it was really composed of two
more powerful Karl I units with a common feed. It was also
modified so that any desired standard type of modulation could
be substituted at the site where it was employed, thus
obviating the necessity for returning the transmitter to the
factory, as was the case with Karl I.
The Karl II employed an LS.1500 valve with an output of
2 kW, and besides being used against ground radar, it had been
modified for use against R/T with the Post type of modulation.
It was not known what degree of success had been achieved with
this set.

KARUSO.
The original Karuso I was improvised by the R.P.Z. with the
specific object of providing aircraft with an airborne
transmitter to jam the R/T link between the British ground
control stations and British night fighters. It was origina11y
intended to sweep through the whole 100 - 120 mc/s band. 0wing
to the relatively large frequency sweep, however, jamming was
not vary effective, so it was manufactured in two forms, to
sweep from 100 - 110 or from 110 - 120 mc/s.
It had ultimately an effective range of about 5 km. and a
power of about 30 Watts. Altogether, only 100 sets were
manufactured.
The designation Karuso II was given to a development which
never got farther than the laboratory stage, but Karuso III
was produced and covered the 100 - 150 mc band. The width of
the jamming band was only 3 mc/s and the frequencies used was
set up on the ground according to intelligence information
given by the German "Y"-service. It was not known whether this
set was used operationally.

KETTENHUND.
Kettenhund was a 30 watt air-born jammer developed in 1943
by a certain KETTEL of Telefunken covering the 170 - 200 mc
band. It was used against British ground radar stations in
raids over South-West England in 1944. Tests with the set led
the Germans to the conclusion that it was not very effective.
Modulation employed was a triangular wave with a frequency of
several hundred kc/s.

KLYSTR0N.
This was the name commonly applied to a centimetre jamming
transmitter witch was also referred to as the "Postklystron".
It acquired this name because it made use of a centimetre
klystron valve developed by Dr. GROOS of the Reichspost. A
power of 100 watts was claimed for it. It was a CW jammer
which could be tuned by hand between 8.5 cm. and 9.5 cm. It
was fitted with a horn aerial to be aligned on the approaching
H2S force. It was claimed that at a range of about 40 km. the
H2S tube was completely obliterated when the Postklystron was
focussed on an individual aircraft. This set came into
operation about March 1945.

KOBOLD.
The Kobold was an airborne set designed by the Post
specifically to jam A.S.V. and was originally used in the
Mediterranean in conjunction with a Karl transmitter working
from the ground. It was, in effect, half a Karl transmitter
and used two LS.180 valves. A modulation of about 400 cycles
originating from the aircraft transformer was superimposed on
it. It had the handicap that it could only be built into very
large aircraft.

NERVTÖTER.
Nervtöter I was designed as an airborne transmitter to jam
Allied R/T but considerable difficulties were encountered in
tuning it in the air to the frequency observed and it was
never used in operations.
As a result of the criticism made by T.L.R., the Nervtöter
II, which was also believed to be known as FuGe. 40, was to be
developed. This set employed an LS.50 valve in the final stage
and the frequency of the R/T was to appear as a blip along is
time base on a cathode ray tube, while the frequency, to which
the transmitting jammer was adjusted, appeared on a similar
blip on a second time base on the tube. By setting these two
opposite each other the operator could easily see that he was
jamming the required frequency.
A so-called chime modulation of four changing tones was
used. The power output was 25-30 watts and the frequencies
ranged from 90-160 mc/s. Wide band aerials were to be used.
This set had not got beyond the experimental stage by the end
of the war.

OLGA.
Olga was a self-excited, grid-keyed, one valve transmitter
(LS.180) developed by the Navy and had a frequency range of
150 - 200 mc/s and an output of about 300 watts. It was
believed that a p.r.f. of 500, 700 or 900 cycles was used.
This jammer was an early type used against British coastal
watch radar without much success.

RODERICH.
This was the name applied to the first set developed by
Siemens for jamming H2S when panic counter-measures were
called for early in 1943. It used a magnetron valve with a
maximum power output of 5 watts and was virtually of no use
whatsoever. It took some months to develop; in the meantime,
German knowledge of how to Jam H2S had increased to such an
extent that it was never used.

ROLAND.
The Roland jammer was developed for use against H2S by Dr.
WEHRMANN of Siemens and was said to employ a triode
transmitter valve designated L.D.72 or possibly L.D.75. The
wavelength was 8.5 - 9.5 cm. and with the aid of a horn aerial
it produced a 30° beamed transmission, modulated, it was
believed, by 100 kc sine wave and pulses of an unknown p.r.f.
It had less than 50 watts average power. The range at which
obliteration of the H2S tube was claimed, was about 30 km.
The Roland II was the name applied to an attempt to produce
a similar set on 3 cm using, it was thought, a LD.77 triode
valve and a horn aerial a 20° beam. It is doubtful if it was
used operationally as the valves had a very short life.

STARNBERG.
This was believed to be the precursor of Kettenhund and was
designed by D.V.L. Adlershof in about 1940 but never used. In
a document there is an indication that attempts were later
made to use it as an R/T airborne jammer; A.D.I.(K) 231/1944
also gives an account of preparations to use the Starnberg
operationally.

WOLKE
Wolke was believed to be the code name applied to the first
German attempt to imitate a noise jammer like that used by the
Allies. It was believed to use two L.D.5 valves in the final
stage and to have a carrier frequency of 90 mc/s. The average
power output was 15 - 20 watts, the width of the noise band
being about 2 mc/s.
As a result of the examination of Wolke the conclusion was
reached that noise modulation required too many valves and too
much power and that with the some number of valves a better
effect could be obtained with other types of modulation. The
set was therefore used for training night fighter crews to see
through electronic jamming of SN.2."

[Bruce Dennis]

SECRET A.D.I.(K) Report No.320/1944
THE FOLLOWING INFORMATION HAS BEEN OBTAINED FROM P/W
AS THE STATEMENTS HAVE NOT AS YET BEEN VERIFIED, NO
MENTION OF THEM SHOULD BE MADE IN INTELLIGENCE
SUMMARIES OF COMMANDS OR LOWER FORMATIONS, NOR SHOULD
THEY BE ACCEPTED UNTIL COMMENTED ON AIR MINISTRY
INTELLIGENCE SUMMARIES OR SPECIAL COMMUNICATIONS.

A GERMAN RADAR STATION AT DOUVRES.
1. The information contained in this report was obtained from
selected P/W of the 8th Kompanie of Ln. Regiment 53, who were
captured on 17th June 1944 at a Radar station which they were
manning 2 km. to the East of Douvres. The site consisted of
two Würzburg Riese and two Freyas without the A.N. attachment;
one of these Freyas was of the mobile type, and was not
operational pending its being changed for one of the fixed
type.
2. The operators as a whole were not particularly
knowledgeable, but were able to give some interesting
information on the way in which Allied air attacks affected
operational efficiency of the station. One member of the
station, an officer, was more knowledgeable than the others
and added some odd scraps of information on other Radar
equipment, which are summarised in this report.

DAMAGE BY ALLIED AIR ATTACK.
3. The beginning of May saw the opening of almost daily air
attacks on the Radar station at Douvres; from this time until
D-Day the site was subjected to bombing, machine-gun and
rocket projectile attack from Thunderbolts, Typhoons and
Spitfires.
4. Surprisingly little resulted from those attacks; eight men
had been killed and one barrack building had been burnt out,
but the Radar installations themselves, protected as they were
by heavy brick work, were practically undamaged. Apart from
short intervals of a few hours for repairing cables and
aerials severed by M.G. fire, the installations were,
according to P/W, continuously in operation.
5. It was stated R.P. attack was particularly ineffective,
but that machine gun fire into the cabins of Radar
installations was both feared and effective. During air
attacks, therefore most of the personnel of the station,
including crews from the Würzburg and Freya cabins, went to
the "Bunker" shelters.
6. On the night of 6th/7th June, the Kompanie had been busily
employed in plotting Allied shipping and at 0100 hours on that
night the Würzburg had plotted same 100 ships, which
information was passed through to Jafü 5. At 0300 hours a
large number of bombs fell in the neighbourhood and all the
personnel left their posts to take to the shelters, leaving
the apparatus unattended.
7. From D-Day onwards the Würzburgs and Freyas were kept
operating even with the added weight of artillery and tank
attack and the equipment was, in fact, operational until a few
hours before the site fell to the Invasion Forces. It is,
therefore, clear that in an operational sense the site
survived nearly five weeks of constant attack.
8. When capture became imminent, however, all technical
apparatus on the site was destroyed by explosive charges. The
personnel put up a good defence, and it was not until the
Allied tanks broke through the protective minefield that the
station finally surrendered.

PLOTTING ROOM.
9. The plotting room on this site, which correlated data
received from the Freya and Würzburg, was housed on the top
floor of a two-storey "Bunker" - a box like building partly
sunk in the ground and constructed of concrete two metres
thick. It had originally been intended that, in addition to
handling normal Würzburg and Freya searches, the plotting room
should also be employed for control of night fighters, but
since there were no night fighters operating in this area, this
latter function had never emerged; in any case the Seeburg
Tisch had not been installed, although provision for it had
already been made.
10. At the time of the Invasion, the plotting equipment
consisted of a ground-glass screen, measuring some 8 x 12 ft.
let into a wall, the glass bearing a map on which the plots
were drawn. In addition to this a small-scale map of Northern
France, overlaid with tracing paper, was laid flat on a table
but this latter had never been put into use, having been
forestalled by the Invasion.
11. In operation, plots from the Würzburgs and Freya were made
in pencil, no distinction being made on the ground-glass
screen between friendly and enemy plots.
12. The plotters, who wore earphones, received their
information direct from the operators of the Freya or
Würzburg, and transferred their plots to the ground-glass
screen. A man called an "Ableser" then read off the plot from
the ground-glass screen and telephoned it to Jafü 5 at Bernay,
and latterly in the Western suburbs of Paris.
13. At one end of the room there was a platform on which sat a
supervisor, who was responsible for the accuracy of the
plotted information. He kept his eye on all plotting whilst
listening to information as it came from the Radar equipment.
He had a small telephone at his side through which he could
plug in to any line from Würzburg or Freya.

SOME NOTES ON RADAR EQUIPMENT.
General Remarks.
14. The only knowledgeable P/W, an officer, gave as his
opinion that British and American Radar technique are slightly
ahead of their German counterpart. In German Signals circles,
he said, it is openly admitted that any piece of Allied radar
equipment is seized upon and studiously copied.
15. One major difference, he believed, was that Allied Radar
equipment was always smaller and more compact in construction
than similar German apparatus.
Hand written comment: but the German Rotterdam weighs about
half H2S - its British original!
16. Some few details on current German Radar Geräte were given
by the above source. These are summarised below.
Würzburg.
17. The Würzburg Riese on the station at Douvres were of the
usual type, and had a search range of 30/40 kilometres.
The frequency of both Würzburg Riese was stated by P/W to be
600 mc/s.
"Window".
18. Some operators of the Würzburg and Freyas, although
agreeing that they experienced interference from "window",
interference which showed itself in a series of specks and
lines on the presentation screen, maintain that because
"window" travels more slowly than an aircraft, an experienced
operator can distinguish the flight of the aircraft against
the tracks of the "window".
19. The officer P/W, however, is sceptical about all anti—
window devices, and believes that the German Radar authorities
are seriously perturbed by it.
20. Some few weeks ago Goering, it is alleged, offered a cash
prize of 300,000 Reichmarks to any Signals personnel who could
invent an apparatus to outwit "window".
Nürnberg Gerät.
21. According to P/W, the Nürnberg Gerät is fitted to Würzburg
in order to eliminate the effects of "window". This apparatus
has not been entirely successful, although it makes the
operator's job slightly easier.
"Würzburg Laus".
22. The "Würzburg Laus" is said to be an apparatus replacing
the Nürnberg Gerät as a counter measure for "window". The
apparatus in contained in a box 18 x 9 x 9 inches, which is
attached to the Würzburg.
23. The "Laus" is a much more recent development, and is said
to be somewhat more successful than the Nürnberg Gerät.
Flanderzaun.
24. This is the colloquial name given to highly characteristic
interference pattern on the screen of the Würzburg and Freya.
The word is apparently associated with the barbed wire
entanglements of Flanders in the last war, and this gives some
indication of the picture which the interference makes.
25. P/W believed that this interference is a transmission
apparently on the frequency on which Würzburg and Freya are
operating, and same P/W have the idea that it emanates from
the Isle of Wight vicinity.
Köthen Gerät.
26. The "Köthen Gerät" is, according to P/W, not an apparatus
but a frequency of the Freya. For example, particular
frequencies on Freya are designated A, B, C and D, and Köthen
is merely another frequency deriving its name from an
experimental station at Köthen.
27. The A, B, C and D frequencies, P/W thinks, were produced
by civil firms, and the Köthen name implies that this
frequency is a development of the Luftwaffe's own experimental
station at Köthen.

"Limbach".
28. Amongst documents found at the Radar station at Douvres
was a paper headed "Limbach"; this piece of apparatus was
stated to be attached to the V.H.F. transmitter/receiver in
the aircraft and to operate in conjunction with the Freya on
the ground.
29. The paper stated that the procedure employed with this
apparatus was similar to that of the Gemse - Erstlings
procedure, but strangely enough was used in conjunction with
the FuGe 7.
30. According to this P/W, the Limbach was superseded by the
Gemse - Erstling (FuGe.25).
31. The document in question has been forwarded to A.D.I.(Sc).

Rammstoss Gerät.
32. This is stated to be an instrument carried in German
bombers, its purpose being to show the position of other
aircraft and prevent collisions in tight formation.
Rotterdam Gerät and Panorama Gerät.
33. It is stated that both these instruments, Allied in
origin, are now being used by G.A.F. aircraft, but all P/W had
heard was that the Panorama Gerät had a wide focus, whilst the
Rotterdam Gerät was designed to show a small area.

Diana.
34. At long last, after a lapse of 21/2 years, confirmation of
"Diana" has come to light through documents. The first
mention was from a notebook of a P/W of I/K.G.30 in August
1941 (A.D.I.(K) 420/1941), which stated that Diana was to be
similar in principle to Elektra, but working on a short-wave
band and within a frequency range of 3,000/6,000 kc/s.
35. The present document notes that "Diana" is similar to
Elektra but operates on short waves. This P/W stated that
"Diana" had not been operational.

ORDER OF BATTLE - LN. REGIMENT 53.
36. The 53rd Ln. Regiment, to which the 8th Kompanie at
Douvres belonged, consists of a number of Kompanien ranging
from 1 to 26; The Kompanien are not necessarily numbered
consecutively, so that the total in the 53rd Ln. Regiment may
therefore be less than 26. All the Kompanien had code names.
37. The 53rd Ln. Regiment was responsible for an area bounded
on one side by the coast, and on the other sides by a line
running from the tip of the Cherbourg peninsula to the South
of Paris and northwards to Dieppe. Its Kompanien lie all along
the coast and towards the interior at a distance of 30/40 km.
apart; each Kompanie's area overlaps so that the entire
territory is completely covered.
38. The H.Q. of the 53rd Regiment is in Paris and is under the
command of Oberstleutnant FLECH, with Major HOFFMANN as
Deputy.

25th Kompanie.
39. The 25th Kompanie is the H.Q. Kompanie and has a strength
of 20/25 men, who were engaged in visiting Freya and Würzburg
sites of the Regiment and doing minor repairs. It was stated
that these men were by no means skilled engineers, and knew
nothing of the internal workings of the Freyas and Würzburgs.
8th Kompanie.
40. The 8th Kompanie at Douvres had a total strength of 160
men, who were divided as follows:-
Kompanie Stab............ Administrative Staff.
Zug 1 )
Zug 2 ) ................. Personnel manning the Freya
and Würzburg on six-hour
shifts day and night.
Flak Zug................. Personnel manning and
guarding Flak position
round the Kompanie’s site.
41. Another Kompanie of this Regiment, the number of which was
unknown to these present P/W, was said to be manning a site at
St. Valery-en-Caux.

MORALE.
42. Generally speaking, the morale of the 8th Kompanie during
the pre-Invasion raids was high, and their resistance during
the final attack on the station was certainly not suggestive
of low morale. It is noteworthy, however, that since capture
and the absence of the excitement of action, these P/W are
heartily glad to be out of the war. The majority are convinced
that Germany has already lost the war.
SEE APPENDIX OVERLEAF.

A.D.I.(K). S.D. Felkin,
30 June 1944 Wing Commander

1. The Deputy Commander of the 8th Kompanie at Douvres
an Oberleutnant - was good enough to bring his paybook with
him, and his career is therefore set out below as a matter of
interest.
Oct. 1937 – March 1938... Was with Ln. Abteilung R.L.M.,
2nd. Komp. at Potsdam (This was,
supposed to be one of the very
elite schools for Signals in
Germany before the war).
March 1938 – April 1938.. Was with Ln. Abt. R.L.M. 2nd. Komp.
in Vienna, and took part in the
Anschluss.
April 1938 - Aug. 1938... Back to the R.L.M. 2nd. Komp. at
Potsdam.
Aug. 1938 - Sept. 1939... Acted as Funker to Ln. Regt. 4,
7th Komp. in Vienna.
Sept. 1939 - Feb. 1940... Became a Horchfunker with Ln. Regt.
4, 7th Komp. At Cracow.
Feb. 1940 - March 1940... Was posted to the Ln. Officers'
Training School at Halle.
April 1940 - Aug. 1940... Joined Ln. Regt. 4, Abt. III as
Staff Officer. Here he was
in command of a Hörstelle.
Aug. 1940 - April 1941... Became O.C. of Horchstelle (W.24)
at Breslau. (P/W explained that all
these Hörstellen are described in
passon and paybook as Wetter
Funkempfangstelle which is in fact
only a cover name for Horchdienst).
April 1941 – March 1942.. Was at the depot of Horchstelle (W.3) which is at Athens. Here his job was to listen in to English ground telegraphic messages which were coded and decoded.
March 1942 - April 1942.. Posted to Nikolaiew in Russia as Staff Officer to III Abteilung Ln. Regt. 4.
April 1942 - May 1943.... Served in Ln. Regt. 130, who were
there in the South Russian sector in support of a Flak division.
May 1943 - May 1944...... Became O.C. of the 11th Komp. Of
Ln. Regt. 57 and later O.C. of the 7th Komp. Of the same Regiment then
near Orleans.
2. In May 1944 he was posted to his present unit (Ln.53, 8th
Komp.) as Second-in-Command to Hauptman EGLE. He says that it
was intended that he should take over this Company in a very
few weeks' time.
Decorations:
Erinnerungsmedaille for Austria.
Erinnerungsmedaille for Sudetenland.
K.V.K. Second Class with Swords.
Rumanian Cross given to those who fought against
Communism.
Krimm Shield, which commemorates the battles of
the Crimea, including Sebastopol and Kersch and
last:-
E.K.II.

[Bruce Dennis]

SECRET A. D. I. (K) Report No. 318/1944
THE FOLLOWING INFORMATION HAS BEEN OBTAINED FROM P/W
AS THE STATEMENTS HAVE NOT AS YET BEEN VERIFIED, NO
MENTION OF THEM SHOULD BE MADE IN INTELLIGENCE
SUMMARIES OF COMMANDS OR LOWER FORMATIONS, NOR SHOULD
THEY BE ACCEPTED UNTIL COMMENTED ON AIR MINISTRY
INTELLIGENCE SUMMARIES OR SPECIAL COMMUNICATIONS.

GERMAN KNOWNLEDGE OF 'OBOE'.
1. Attached is a translation of a paper issued by the General
der Flakwaffe on 24th May 1944 concerning the British 'Oboe'
procedure - called by the Germans the Boomerang.
2. Apart from showing that the enemy understands the working
of 'Oboe' the report is of interest as it indicates the lines
on which German defence was concentrating. Night-fighters are
dismissed summarily and the main hope is that, by knowing the
approach course, the height and the speed of the attacking
aircraft, the Flak defences must be concentrated near the bomb
release point so as to produce a "Vernichtungsfeuer" by which
success was certain. The report also hints that, since the
German knew the 'Oboe' frequencies, radio counter-measures
were in hand.
3. One other point of interest is the high standard of the
plots of aircraft attacking on the night of 2nd February 1944.
This Sketch of is reproduced as Appendix II.
4. The original document has been passed to A.D.I.(Science).
A.D.I.(K) S.D. FELKIN
29 June 44. Wing Commander

TRANSLATION SECRET
("TOP SECRET")
Oberkommando der Luftwaffe Bernau b/Berlin d.24.5.1944
Tel.: Berlin 56 40 76 App.:122
General der Flakwaffe Bernau 814 u.815 od.üb.
(General der Flakausbildung) L.V. 12.
Az. 79 m Nr.0236/44 g.Kdos.(A/C)
Number of Copies: 250.
Copy N°: 79.
Subject: Combating "Boomerang" Aircraft.
Attached are instructions for dealing with aircraft attacks using the Boomerang procedure.
In view of the importance of defence against this new method of attack adopted by the enemy it is imperative that all units be instructed in the Boomerang procedure and that counter—measures are adopted on the lines laid down in the attached instruction.
Subsequent observations and experiences are to be reported to the General in charge of A.A. defences.
Distribution:
All independent Flak Groups as well as interested sections of
O.K.L., O.K.H., O.K.M., SS-Führungs-Hpt.-Amt, Höhere Kdre.,
Flakersatzdivision General der Jagdflieger,
Generalnachrichtenführer, General d. Kampfflieger u.
GL/Flaktechnisches Amt.
(Sgd) v. Axthelm.
Generalleutnant.

TRANSLATION SECRET
("TOP SECRET")
Encl. To: OKL – Gen.d.Flakwaffe
(Gen.d.Flak-ausb.)
Nr.0236/44 g.Kos. (A/C)
Dated 24/May/44.
A. General.
Recently, nuisance raids have been developing more and
more into high altitude precision attacks against pin-pointed
targets (particularly important industrial complexes) by means
of a special navigational procedure known as the "Boomerang"
procedure. So far, "Boomerang" attacks have only taken place
at night on the Rhine-Westphalian industrial area, Aachen and
Osnabrück, airfields and railway stations, in the area of
Luftgau Belgium/N. France, Paris and targets in Brittany.
The "Boomerang" aircraft employed were Mosquitoes belong
to 105 and 109 (B) squadrons, stationed at Marham. Immediately
after take-off the aircraft climb to the prescribed attacking
height of 8,000 to 11,000 metres, with a view to checking wind
drift.
The enemy is carrying out on an increasing scale his precision attacks and pathfinder technique using the "Boomerang" procedure. It is clear from the increase of activity that the enemy is constantly expanding his
"Boomerang" organisation and improving the technique. An expansion of these attacks on further targets with ever increasing effect is the result.
It is therefore essential to bring to bear everything in our power with a view to combating "Boomerang" aircraft. The basic principle is that aircraft must be shot down.
B. The "Boomerang" procedure.
The "Boomerang" procedure is the most accurate method of remote control at present known. It consists of controlling aircraft by means of Radar stations located in S., S.E. and E. England. These stations work together in pairs of which one is the main station, and passes navigational signals to the aircraft. One signal from this station indicates the course to
the pilot whilst the other is for the bomb-aimer to release the bombs. (see App. 1).
The aircraft to be controlled flies under its own control to an agreed point, where the remote control takes over. The aircraft is then directed by W/T to the turning point, which is on an arc centred on the Radar station in England and passing through the bomb dropping point. Constant corrections from the ground station in England keep the aircraft on its
course (see App. 1) but in spite of the great accuracy of measurement deviations up to 300 metres are possible.
The total time required for the target approach is 8 to 15 minutes. As soon as an aircraft passes over the target, the next one is taken over by control. The time interval between attacking aircraft is frequently reduced by attaching several uncontrolled aircraft to one controlled aircraft, or by using further pairs of Radar stations. The uncontrolled aircraft aim their bombes on ground or air markers. The approach to targets East of England is made from a N. - S., S. - N. or S. – W. direction. Targets South of England are approached W. - E. or E. - W. The course depends upon the relationship of the two Radar stations to one another. Unless there in a disturbance by a jamming station the final phase of the line of approach becomes an arc centred on the ground control station in England and passing through the objective to be attacked.
It has been observed that simultaneous flights to
different objectives on a N.- S., S.- N. as well as S.- W. and N.- E. courses, have been carried out, which proves that the enemy has already set up several ground stations.
The range of this system is limited by the curvature of the earth and for a flight at a height of 9,000 metres, the range is between 400 – 450 km. The bombing accuracy depends on the reading and measuring accuracy of the ground station in England. The accuracy is within a square of approximately .5 km. by .5 km.
So far, the followings types of "Boomerang" attacks have
been made:-
a) Single "Boomerang" aircraft.
b) One "Boomerang" aircraft followed by 2-5
uncontrolled aircraft.
c) "Boomerang" aircraft as Pathfinders for a
following bomber force.
d) "Boomerang" Pathfinders as decoy marker flaredroppers
and "window" aircraft. (Translator's note:
the German text is ambiguous. The word is
"Scheinmarkierer" which may mean decoy or
illuminating markers. The subsequent context
suggests the former).
The "Boomerang" Pathfinders at first saturate the approach and target area with "Window", then place light markers over the target. The bomber stream then follows up immediately on the "Boomerang" course.
C. Counter-measures.
The following take part in "anti-Boomerang" attacks:
a) Night fighters.
b) Radio jamming service
c) Flak.
I. Our own Mosquito night-fighters (sic) have not had any worth-while successes in shooting aircraft down prior to the bomb release or to the commencement of the Pathfinder activity.
Over a period of time, however, night-fighters should be more successful, provided high flying aircraft are employed. Uncontrolled night-fighting with the aid of search lights is possible if our own fighters are high enough and in sufficient numbers in the waiting area over the Flak zone.
Because of vapour trails, it is possible to pick out highflying aircraft by searchlights.
II. The radio jamming service has appreciated the principles
of the "Boomerang" system and has set up jamming stations. It
is possible to force part of the approaching aircraft off the
approach line by jamming. However, the enemy soon recognises
the disturbance and can change over to a pre-arranged
alternative frequency. The radio jamming service has already
met with success, but is still limited in its effectiveness.
III. The main burden of defence, now as before, rests with the
Flack. For the successful execution of the "Boomerang" system
conditions must be fulfilled:-
1. The attack must take place at a constant height of
about 8,000 - 11,000 metres.
2. The target approach must follow a fixed course for
several minutes. (Course for every objective known).
3. The ground speed must remain constant throughout the
approach. (140 - 180 metres/s.)
These known and partly constant target factors constitute
a great weakness to the enemy. In addition the Mosquito,
because of its wooden construction, is highly vulnerable to
well-directed Flak.
If, in spite of these favourable conditions, the Flak has only so far obtained little success, the fault lies in the increased factor of error when engaging targets at great heights, and also to the high speed of the Mosquito.
On the other hand, the courses flown at the moment are well-known. This factor, together with the known target heights and target speed, enable the point of bomb release for each individual objective to be calculated accurately and in advance. These known facts, combined with the total fire-poor of all batteries within reach of the bomb-releasing area, should produce a successful "Vernichtungsfeuer" (annihilation fire) and prevent accurate bombing and lead to aircraft being shot down.
D. Methods of Shooting.
1.) The shooting method employed on principal is annihilation fire.
2.) Provided that:
a) The course is known,
b) The target approach is fixed and confirmed by the
Malsi Flak Calculating instrument.
c) It is known with certainty that our own radio jamming does not result in the deviation of the enemy aircraft from its course and that the speed
and height remain constant. This contradicts L.Dv.400/4b und VER-Flak 18 Ziff.11)
3.) If the precise plotting is difficult, the following measures are to be taken:
a) The track is to be set in accordance with the known value.
b) The ground speed is to be obtained and passed on by the Flak transmitter. In the absence of this data, action is to be taken on the basis of previous experience. (Translator's note: in other words, use your own brains).
c) Height is to be obtained from accurately adjusted Radar and is to be passed over the Flak transmitter.
4.) With reference to the manner, in which "Boomerang" coursers are to be obtained for individual objectives, Commands will contact Luftgaukommando VI with a view to ascertaining the courses for their own
particular area.
E. Tactical Employment.
Suitable steps must be taken in the event of a change in the direction of approach of "Boomerang" aircraft, and if possible one to two batteries (special Eis. batteries) will be brought into the probable direction of approach for immediate action.
F. Counter-measures.
The following is to be noted when combating "Boomerang" aircraft:
1.) Most accurate alignment of the respective batteries (adjustment of instruments and guns, calibration of direction-finding apparatus, re-checking of ballistic correction of the moment in order to eliminate the
meteorological factor).
2.) Blocking together of the movement of target values:
a) Set course for known value.
b) Determine ground speed and height from previously emplaced batteries over Flak transmitter.
3.) As far as possible the Trupp should be provided with uniform ammunition (as few different batches as possible); calibration shoots should be carried out with this ammunition and muzzle velocity
determinations with (?special) calibration ammunition should be avoided.
4.) Accurate meteorological reports must be obtained every two hours for heights up to 11,000 metres. These must be actual and not extrapolated. Contact must be made with the nearest airfield.
5.) Charge temperature should is periodically determined by means the two specially equipped cartridges (Messcartuschen) placed in the ammunition dump.
6.) The ammunition used for checking drill time should be carefully controlled and the error should be eliminated.
7.) Preliminary practices should be made along the known lines of approach by means of special fire control tables prepared for this purpose. Test shoots should be carried out using intervals of one second. (FAS I
will supply fire control tables for "Boomerang").
8.) All actual "Boomerang" courses should be charted on the Malsi plotting table as a check against the actual plots. (See Appendix II).
A systematic research of shooting at great heights, having due regard to the available ammunition has been inaugurated. Results are to be expected shortly and until then all existing orders and instructions
hold good. In order to keep counter measures apace with the enemy's intentions, it is essential to inform higher quarters of any new observations made during "Boomerang" attacks. The Luftgaukommando and Divisions are instructed to report regularly their experiences of "Boomerang" counter-measures to the General der Flakwaffe.