Well, Erich, I have excellent information on German radio and radar developments. What I would like on their systems is more on sonar / hydrophones, particularly the Gruppenhöchtgerät (GHG) used on the very late war newer model U-boats like the Type XXI.
I would like to be able to compare the technical qualitites of the German systems with the Allied ones in this area. I'm sure that, as with radar, the Germans didn't develop anywhere near as many different systems as the Allies so it should be a fairly short list.