[600MRG] Regen Rx? I'm Missing Something?

[Kenneth G. Gordon]

On 24 Feb 2018 at 11:56, Steve wrote:

> >> If anyone mentioned the autodyne circuit I missed it. A good description
> >> is at:
> >> http://www.rfcafe.com/references/qst/rationalizing-autodyne-january-1933-qst.htm
> 
> 
> I built this exact one and have written about it, along with an audio file, 
> tuning across 40m on the first night with it:
> 
> http://www.qsl.net/ve7sl/regen.html
> 
> Steve

Steve (and others): 

1) where did you get that delightful dial? I've been looking for one of those for years. 

2) I see that Grammer chose 5 megohms for the grid-leak, but 250 pFd for the grid coupling 
cap. Somewhat recently, several of us discovered that using something like 10 to 20 
megohms for the grid leak, and on the order of 10 - 20 pFd for the grid coupling capacitor 
vastly improves selectivity. In several cases, such that it caused significant "sideband 
cutting" when listening to AM or SSB. This, of course, requires a VERY stable detector 
stage.

3) In my opinion, the Paraset's receiver is very crude, and I suspect the designers of the 
Paraset expended far more sweat on the design of the transmitter than the receiver.

See this:

http://www.w7ekb.com/glowbugs/tx/paraset.htm

4) You and others may find this of interest:

http://www.w7ekb.com/glowbugs/rx/Regens/ZL2JJ/zl2jj_trf.htm

Lastly, I have used an RAL-7 and an RAK, both TRF receivers, many years ago and found 
them, and still find them, to be superb receivers for any sort of serious radio work.

They are stable, selective and sensitive. The RAK, in fact, exhibits "single signal" selectivity, 
due, I am certain, to the very high "Q" RF and detector toroid coils wound with Litz wire. The 
"other side of zero beat" simply is not there.

Ken W7EKB

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