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

[Ian Wilson]

I don't recall where I got the idea about the RU amplifier stages being
regenerative.
I do seem to remember that they will oscillate if the shielding in place.

Why is the second harmonic of the BFO used (easy way to attenuate the signal
perhaps)?

73, ian K3IMW

On Mon, Nov 9, 2015 at 11:39 AM, Hue Miller <kargo_cult at msn.com> wrote:

> 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
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