Here is a link to a discussion forum about radio and radar that should help:
http://www.network54.com/Forum/19487/
You may also want to locate the German language books by Fritz Trenkle on this subject.
In English, there is an excellent book entitled "GEMA: Birthplace of German Radar and Sonar" by Harry von Kroge. You can view it at amazon.com The back cover writing is especially enlightening, and the contents list can be seen as well.
Usual disclaimer,
Ed