[Elecraft] AGC voltage preference

[Sverre Holm]

> SN 3777 was initially adjusted to 3.8 volts per the 
> instructions.  I did 
> notice that there was a definite increase in audio out when 
> the AGC was 
> switched off while monitoring a quiet spot on any band.  I tried to 
> adjust the AGC value until there was no difference, 

This is the best way to adjust the AGC threshold, use the 3.8 Volts as a
starting value only.

> however this 
> resulted in spooky S-meter performance and some other bad behavior.

A changed S-meter is a result of a changed AGC threshold, since the
S-meter is derived from the AGC voltage. One has to readjust the S-meter
setting each time the AGC-threhsold has been changed.

However, some of us have found the S-meter to be a little insensitive
(stingy is what the natives call it!). This can be tuned by playing with
the CAL S HI setting. My procedure is as follows:

- First set CAL S LO as per the manual

- Then adjust CAL S HI by setting RF GAIN to the 9 o'clock position
(instead of fully CCW) and set parameter so that right-most bargraph is
barely turned on. I have played with various other setting such a 10, 11
o'clock, but found the 9 o'clock position to be fine. It also agrees
reasonably well with 50 uV from my generator to give S 9. 

If the AGC-setting is changed, the S-meter calibration has to be redone.

--
73, 
Sverre

------------------
Sverre Holm, LA3ZA
www.qsl.net/la3za