[Milsurplus] TRF ( Milsurplus Digest, Vol 139, Issue 13 )

[Hue Miller]

The LF receiver I posted about just previous IS a TRF. It is non 
regenerative.
TRF does not always indicate regeneration.
I do not think the RU rf stages to be regenerative in the least. That would 
only exacerbate any sensitivity problems in CW use. If the rf stages WERE 
more selective,
problems with accuracy of tracking would arise, since the BFO is at hf. ( 
Actually, it's at 1/2f )

The Axis used a high proportion of regenerative receivers in ground and ship 
applications.
However, the only actual TRF, I mean straight TRF, used by the Axis was the 
radio used in the Stuka plane. I don't recall the Fu-* number and I don't 
want to look it up. It is a primitive
looking apparatus. That, the  RU and the BC-229/ 429 were the most, uh, 
primitive designs used in aircraft in this war, AFAIK. Japanese equipment 
was mostly mid-1930s
designs and often didn't seem to work that well, as reported by its users, 
but even they declined anything primitive as a TRF ( straight TRF ) or 
regenerative receiver for
aircraft.

Kind of ironic to see in captured Japanese planes, for flight test studies, 
the original Japanese superhet-receiver radios removed and U.S. RUGF or 
SCR-183
equipment installed. A kind of downgrade, but it did work, and nothing to 
figure out.

The U.K. started with some kind of regenerative-detector low power voice 
radio for fighters. I don't recall the type number but I think Dave Stinson 
has one.

The Marconi 730 ship's receiver, a 4-tube circuit, has one tube working ~16 
kHz oscillator for when receiving RGB vlf station. This to deal with the 
offset of
the regenerative detector otherwise. ( The manual for this receiver is 
online, surprisingly enough. )  ( Last reported use I've seen is when in 
1947 a British
cargo ship sank off the coast of Canada. It had a Marconi 730 paired with a 
spark transmitter - no lie - the board of inquiry stated that. )
-Hue Miller