[Elecraft] K3 AGC THR doesn't go low enough

[Carl Clawson]

Nice writeup, Don. Thanks!

But the one thing I haven't seen mentioned in this month's installment of
the "noisy K3" discussion is setting the RF gain control. I got into the
habit long ago of using the RF gain to quiet the band noise to a reasonable
level -- after setting pre-amp, attenuator, and AF gain appropriately. We
didn't have AGC parameters to play with back then except maybe
Fast/Slow/Off.

If the K3's "RF" (actually IF) gain control works the way most rigs' do, it
is providing a bias to the AGC control voltage. In other words, it is
providing a maximum gain that will not be exceeded by the AGC's feedback
action. Is that not an equally valid way to control the level of band noise?
Apart from it being manual instead of automatic, is there any drawback to
it? I can imagine that it could interact with AGC dynamics in some
unpleasant way, but if so I haven't noticed it yet.

The K3 is only the second HF rig I've owned in 23 years as a ham. My first
was an Icom 735, and it is quite noisy on the low bands if the RF gain is
all the way up. I've heard quieter rigs, but it never occurred to me to
think of them as better just because of that.

73, Carl WS7L
K3 #486 

> -----Original Message-----
> Go to www.w3fpr.com and click on the link in the left column 
> referring to K3 noise and AGC settings.
> It is an expansion of the post I offered earlier today 
> dealing with AGC settings and their relationship to K3 noise.
> 
> 73,
> Don W3FPR