Steve Nosko wrote:
Thanks for the interesting examples, Jan-Martin. The
quote was from the 2004 ARRL HB page 17.23 in reference
to a schematic/block diagram of a "typical superhet
receiver with AGC applied to multiple stages of RF and
IF". The RS DX-394 bears some resemblance to this with a
resistor in place of the "Delay Diode". It beats me how
the AGC in this HB example actually controls the RF gain
- the diode appears to block control. A second one in
parallel in the opposite direction seems to me to be
needed.
I don't have the circuit, but have two diodes
pointing down. [snip]
That's interesting, Steve but the circuit looks like this:

RF Amp----MXR------IF Amp
| |
R R
|------|---------|
| | D |
C R ---from AGC
| |
-----
|
GND

Just noticed an asterix by the 'delay' Diode that says it may be replaced by
a test-selected resistor - that's the way the DX-394 is done.

Tom