[Elecraft] R1 and the AGC

[Don Wilhelm]

Kevin,

Regardless of the voltages involved, what I would adjust that new pot for is
for no change in the background level when turning the AGC on and off (no
signal present) - that is on a band with 'normal' background noise if that
really esists.  Set the RF gain on full, then start with a setting which
DOES result in a change (Background stronger with AGC off), and then adjust
until the levels are the same - that will allow you to determine the 'edge'
of the adjustment range.

There is a lot of judgement (involving one's own ears) in determining the
'correct' setting.  How much band noise should tolerable before the AGC
starts to kick in, what level signal should provide an 'S-9' reading on the
S-meter, and how strong a signal should produce full AGC action.  I believe
these questions are up to the individual operator to decide - and one thing
I do like about the K2 is that as builder and operator, I can adjust
settings like these to my personal preferences instead of accepting the
manufacturer's 'average' settings

73,
Don W3FPR
.
----- Original Message ----- 

| >If your 8-volt regulator outputs a bit more than 8.00 VDC, R1 will have
| >to be set to a value considerably lower than the nominal 50k.  My
| >regulator outputs 8.32 VDC, so my final value for R1 was about 22k.
|
| I have a similar problem. My 8V regulator is putting out 8.45V. I have put
| some trim pots in place of R1 so I can play with its value. Since the new
| K2's have a pot for R1, I will look at the latest manual on the web site
| and see what the procedure is for getting the right value since I have yet
| to read the conditions one needs to set up when looking for 3.8V on pin 5
| of U2. Based on the quoted text above, I will expect to wind up with a
| value less than 22K. The initial adjustments I have made have helped. It
is
| now starting to hear as well as a shortwave receiver nearby.
|