[HBR] Dissipation factor of materials

[Brian Burns]

Hello Ron,

~ True, the "Q" of the RF and mixer tuned circuits won't impact adjacent
channel selectivity, but it will affect the signal/image ratio, front end
gain, and in the case of the RF stage, the receiver noise figure.
                          73 de Ron                        

I'm all for using the coil form material that will make the highest Q coils.
The thing that concerns me about the HBR front end design is what happens
with a regenerative system in the presence of strong adjacent signals. 

If I understand what the guys over on the regenrx list are saying,
regenerative systems overload easily, and the high degree of selectivity
that you get on weak signals, goes away when the QRO boys come out to play.

I've often wondered what is the design idea behind having two RF stages. The
top of the line receivers from the tube era often had two, as did the famous
RAL regenerative receiver used by the Navy. It doesn't seem likely that the
HRO-60 needed that extra RF stage for sensitivity. 

I know that Ted lived by the KISS rule, and I certainly appreciate that. It
seems to me that all design is a matter of figuring out what compromises you
can live with---until there is a breakthrough. Somebody comes up with
something altogether new, and all at once the possibilities change.

Cheers,

Brian




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