Transmitter Reciever TR9D

[Observer1940]

Arnaud

The T.1083 transmitter and R.1082 receiver was the General Purpose (G.P.) W/T (Wireless Telegraphy) set-up and like the 1940 Whitley V which also used this G.P. wireless combination, bomber aircraft usually had a T.R.9F with the above (although I understand that there was more than one combination). The aircraft would also use its R.1082 receiver (with a 'sense unit') to get D/F bearings from known wireless stations and beacon locations, for navigation purposes and homing.

The T.R.9F could be used in addition to the G.P. equipment and also linked via an amplifier (A.1134) to the G.P wireless. The T.R.9F was similar in circuit (to the 9D), but the T.R.9F gave the bomber a "special" second channel for communication.

The actual T.R.9D and T.R.9F had a similar circuit layout.

I have the R.1082 (3.75Mb pdf doc) and T.1083 (6Mb pdf doc) as two pre WW 2 Air Ministry A.P. 1186 docs (they can be found online free of charge at
T1083 - BAMA - edebris.com (or Googling this bama.edebris.com/manuals/britmil/t1083 ) click the "T1083.pdf (5 MB)" link only
and
http://www.ww2aircraft.net/forum/com...nual-8701.html (log in and click the pdf conversion)

Both go into a little more detail as to what can and cannot operate, when certain aspects of the wireless are in operation, circuit diagrams, switching arrangements, additional equipment, photographs and A.M. part numbers etc.

I'm going to really read it all up thoroughly too.

Don't forget the 5 pages of Chapter 10 on the "Transmitters-Receivers T.R.9D and T.R.9F" at http://www.tuberadio.com/robinson/Information/TR9D/ (link given in a previous post by MarkRS to 5 page links), which you can click on to enlarge and then print off each page (by adjusting on your pc 'print preview' menu zoom %).

Mark

[Pieter H]

Arnaud, all,

Trying to reduce the confusion a bit, let me again summarize the different radio sets as used by the RAF by May 1940.

• The basic set for all bombers was the TRF General Purose radio, consisting of the R1082 and T1083. This set operated at low frequency, so large range, and was intended for communication of the individual a/c with their base. With a rotatable antenna it could be used for direction finding. As far as I know this set was NOT used for a/c to a/c communication.
• For fighters there was the TR9D, consisting of the R1120 and T1119, operating at 4.4-6 MHz. Range of this set was very poor, and was useless a few km away from the air field. So it could then only be used for a/c to a/c communication.
• Around May new fighter a/c were started to be equiped with the much better TR1133 set. I expect that not many units in France already used this radio, probably only home based Fighter Command a/c.
• Coastal Command used a simplified version of the TR9D, the TR9J
• The TR9F was installed into bombers probably from the end of 1940, adding a 2nd channel and possibly a/c to a/ccommunication. So it is pretty impossible to find TR9F in May 1940 a/c.

So yes, from that perspective I'm still surprised you've found a Battle with a TR9D. The question is whether it still contained the standard TRF, with an additional TR9D, or had the first one replace with a TR9D. The best explanation is that Battle pilots valued a/c to a/c communication more than communication back to base, and installed the standard fighter equipment.

Regards, Pieter

[Observer1940]

Pieter

Regarding the TR 1133 being introduced in May 1940, the RAF / MoD stated the following in their Battle Of Britain 70th Anniversary publication:-

"Ground-to-air and air-to-air communications were facilitated by another technological advance - very high frequency (VHF) radio. In 1939 Fighter Command aircraft were still equipped with TR 9D high frequency (HF) radios. An operational trial undertaken with the new TR 1133 VHF radio by No 11 Group in October 1939 showed it to be "infinitely superior to the TR 9D (HF) from an operational point of view". "

"Despite its improved performance, delays in production forced Fighter Command to withdraw the TR 1133 from service in May 1940. Although the new set was reintroduced from August 1940, the limited number of VHF radios available nevertheless meant that the majority of squadrons would be forced to continue with the earlier TR 9D HF radio for the remainder of the battle."

Published in association with Royal Air Force Media and
Communications, Headquarters Air Command

www.raf.mod.uk

Mark

[Andy Saunders]

I have never come across any 1940 fighter losses (or early 1941 for that matter!) that had anything other than a TR9D.

[Observer1940]

Originally Posted by Pieter H

Arnaud, all,


Trying to reduce the confusion a bit, let me again summarize the different radio sets as used by the RAF by May 1940.

• Around May new fighter a/c were started to be equiped with the much better TR1133 set. I expect that not many units in France already used this radio, probably only home based Fighter Command a/c.

So yes, from that perspective I'm still surprised you've found a Battle with a TR9D. The question is whether it still contained the standard TRF, with an additional TR9D, or had the first one replace with a TR9D. The best explanation is that Battle pilots valued a/c to a/c communication more than communication back to base, and installed the standard fighter equipment.

Regards, Pieter

(Extract quote from posting)

Hello All

I agree with Andy regarding fighter aircraft using the TR 9D, even the quote I used about the new VHF set being introduced in a very limited way in August 1940, looks over optimistic and as it states the TR 9D was still in use by Fighter Squadrons throughout the Battle of Britain.

There is proof to back up the fact that the new VHF set was not in use by Fighters in August 1940, as the Accident Card for Hurricane P3684 which crashed after hitting a balloon cable on the 19th August 1940 states in part:-

"Did not receive order to alter course. In view of proximity of balloon barrage to drome a/c will be kept above balloon ht until over base. Introduction of V.H.F in near future will ensure that correct signals are received (OC)"

Therefore, the new VHF set was still not in use by fighters.

Even the quote I used about the new TR 1133 VHF set, starting to be introduced in August 1940 now looks over optimistic and incorrect.

Mark

[Buffnut453]

So is there a period when TR1133 set could be considered to be in widespread use? I only ask because, AFAIK, the TR9D was still in use overseas at the end of 1941 and that seems a very long time to be relying on such a poor radio.

[Graham Boak]

Overseas is another matter, because it also relies upon the transmitting network being equipped to the same standard. All this takes time. Spitfire Mk.Vs were built with UK aircraft having the TR1133, but the TR9D was part of the tropicalisation mods. This certainly requires TR1133 as the UK standard by the time of the Mk.V - or at least the tropicalised versions, but I don't have a list of the Amendments to see what was initial equipment for the standard aircraft.

I don't see any particular reason to doubt that the re-equipment with TR1133 could have started in August 1940, or even earlier, but that's not the same thing as complete re-equipment of even Fighter Command.

[Pieter H]

Mark, Andy,

Thanks for the additional info.
I think we're all saying the same thing, namely that the TR9D was the main radio set for RAF fighters in the May 1940 period (and well beyond). All I said was that formally the TR1133 became available around that period, without any statements about its possible widespread use. Your info about the rate of adoption are very interesting.

In fact, looking back, it is rather shocking to see with what quality of radio equipment the RAF aircraft were equiped. The so-called linear or straight receivers are known to have very poor sensitivity (=range) and were difficult to keep tuned (=stable). Almost all German radios of the period were already super-heterodyne, with much higher sensitivity, tunability and stability. And companies like Philips used the same concept in commercial radio receivers. The TR1133, although much improved, was still a linear receiver. That makes it all the more interesting to see that even under the pressure of war it took all of 1940 to get the TR1133 into production. And only the next model, the Marconi T1115/R1116 was finally based on super-heterodyne principles. Although some sources say this one came available June 1940, I suspect operational roll out of this one was not before 1941.

Regards, Pieter