Folks:

Hue wrote:  "I cannot think of a single superhet with an "at IF" regenerative detector the US military every used."

On a parallel topic Al wrote: "The recent Armstrong-Superhet discussion on the ARC-5 list got me looking around for the earliest military superheterodynes.  That might be the  BC-113 Tuner with the BC-116 amplifier in SCR-133/134/135."

The search for info on BC-116 found nothing (although Mr. Google thought I may be interested in the BC-611).

I found NO military superhet with regenerative detector.  In terms of 'underground' sets I found a small selection that included the Polish Pipszhtok, MCR1, A2 and CMS (although this last set seems to be from the 50s not 30s or 40s.  My interest: design, operation in the field and reliablity of these sets.  Talking about the nomenclature of these sets, I found designation uncertain.  An example: The Poles made sets for Europe and their own country, Poland.  Model designations were A2 and AP-2.  I haven't disentangle the difference.  My guess (nothing more) is that that AP-2 was similar (or even identical) to A-2 but destined for/used in Poland.  I do have a circuit for some sets.

The distance from Oxford/Cambridge to Warsaw is 1500km or 950miles.  I imagine the SW frequencies between 3 and 8 or 10MHz were 'busy' in WWII yet the 'underground' sets somehow managed to cross 1500km with low power and unsophisticated receiver.  My guess would be that the operators were well trained.

73 to all

Leslie