[Arran]

Mike;
  There was a radio that the British issued to their agents which used a regenerative circuit, and not surprisingly if it were adjusted wrong the Germans could, and did, triangulate where it was, it was dubbed "The Spy Killer" for that reason. I think someone was trying to cut corners by using that circuit, with it re-adjusted it could be used as an RF modulator for transmitting, but that was a really bad idea as it could also radiate out of the antenna whilst receiving. But then again the British also sold the public on the idea that the radio, and later TV license crews working for the BBC were roaming the streets in vans that could pick up their TV set, and know whether they paid their license fee or not, strange people.
Happy Cristmas
Arran