[Elecraft] Noisy K3 receiver

[Graham Kimbell (G3TCT)]

Wes, thanks for the insight and it's interesting someone else has the same
problem (s meter behaving oddly when rf gain backed off, plus noisy rx).

In my case I had calibrated the rf gain using an external sig gen. I asked
elecraft support about this and at Dale's suggestion I redid the calibration
using factory defaults.  This has cleared the problem with the s meter and
has also removed the problem whereby the S/N reduced immediately I turned
back the rf gain.

Quite what the solution is for you, Wes, I'm not sure, except that doing a
rf gain calibration with different levels of input signal might allow you to
hit the right answer.

At others' suggestions, I have also experimented with AGC parameters. I
found that the rx sounded better with AGC THR=2 (the minimum),  but it could
do with being even lower. (I mean a lower number).

Graham
----- Original Message -----
From: "Wes Stewart" <n7ws at yahoo.com>
To: <elecraft at mailman.qth.net>
Sent: Friday, December 18, 2009 4:09 PM
Subject: Re: [Elecraft] Noisy K3 receiver


"The more you turn RF GAIN back, the higher the S-Meter will read."

Well, that's the way it should work, but I can assure you that with my K3
with the factory default RF Gain calibration, turning the control
counterclockwise from max would cause the S-meter to increase at first, then
*decrease* and then increase again as the control reached minimum gain.

That is why I've said repeatedly, NOT ALL K3s BEHAVE THE SAME WAY with
respect to RF gain and AGC.