[Boatanchors] Audio derived AGC ?

[Philip Atchley]

Hi.
Can anyone direct me to some of the old "Toob" transceivers that used Audio
AGC rather than RF Derived, whose circuits I can download from BAMA?  I
designed my homebrewed Longwave CW receiver with the usual RF derived AGC
and it works quite well in that regard.  HOWEVER, the audio stage consists
of an 8  pole switchable selectivity (yes I used Op-amps) that I want to
include in the AGC loop.  Right now strong signals outside the audio
bandwidth can "pump" the AGC.

Yes, I now that "usually" RF derived agc is better but not in this case.
AND, I know I can design my own AF drived agc circuit but why re-invent the
wheel?  This will be used for CW ONLY so doesn't have to be shaped to voice
patterns.

For those interested in such matters, this receiver consists of 10 "toobs"
and 9 IC's (audio section), solid state rectifers.  It tunes from "zero" KC
(usable down to about 15KC or less) up to 500 KC.  It was built in the
"hulk" of a Lafayette HA-350 hamband receiver AND the ONLY thing stock on it
is the power transformer and the VFO assembly (2nd IF tunes from 3500-4100
KC) All RF and IF sections have been ripped out and "redesigned.  AF
converted to SS for heat reduction next to the VFO and to permit the AF
filters.  It is effectively triple conversion with the product detector and
audio filters acting as the 3rd IF.  I chose the HA-350 due to it's basic
circuit design and availability.  I didn't want to fight making cabinets,
tuning scales etc.  AND the HA-350's tuning dial is 0-500KC, PERFECT!

73 de Phil  KO6BB