[Elecraft] Re: AGC adjustment

[k6se@juno.com]

Hi, Wayne,

You wrote:

"As the voltage at U2-5 goes down, the voltage at pin 1 should also go
down. This in turn should increase the gain of the IF amp (MC1350 on the
RF board)."
----------
With the original value of 51k at R1, there was a slight change in noise
when switching AGC ON/OFF (louder noise with AGC OFF).  When I changed R1
to 42k, the noise change was more noticeable (and the S-meter became more
sensitive).  When I changed R1 to 33k, the noise change became greater
(and the S-meter became more sensitive than my MP's S-meter).
==========

"At some point the IF amp will be at maximum gain; this should occur when
the voltage at U2-1 is around 3.5-3.7 V. Lower voltages then would have
no effect."
----------
I'll pull the cover off tomorrow and measure the no-signal voltage at
U2-1.  I still have the 33k resistor at R1.

What's the expected voltage at U2-1 with, say, an indicated S-9 signal?

73, de Earl, K6SE