[Elecraft] K3 - AF/RF Gain [and S-meters]

[Fred Jensen]

Lots of good info comes from this list.  I segregated all the recent 
"How to set AF and RF Gains" postings to try and see if I'm missing 
something since other than the EQ settings [K9YC's for SSB TX and "try 
to emulate my hearing aid response" for RX], I run pretty much 
out-of-the-box-defaults, AGC on, RF max, AF for volume, and am a really 
happy ham.

In olden days, which have been mentioned here a lot, we ran CW [and SSB 
unless you had a new receiver with a product detector] with AF gain 
firewalled and RF gain for adjustment.  The reason for this, although no 
longer valid with a K3, was to equalize the signal and the BFO injection 
amplitudes.  Minimum distortion occurred when they were about equal, the 
BFO amplitude was fixed, so you adjusted the signal level through the 
receiver to sort of the same amplitude.  The right point was fairly 
obvious.  The S-meter followed the RF gain control ... that's just how 
it was.

AGC used to be a somewhat brute force thing ... 1st mixers had to be 
protected so the AGC line hit the RF stage(s) as well as the IF's. 
SX-28?  My K3 seems to have an exquisitely designed AGC system [well, 
more than one].  I run with it on, I've tweaked the threshold so it's at 
my normal noise floor, and my RF gain is at max.

I cannot tell any difference between my ability to copy very weak CW 
signals in my normal configuration, and when trying to ride RF gain.  In 
light of all the reflector chatter on this subject, I've tried to make 
this work [I'm retired, I have time :-)].  The WIDTH knob can help, the 
APF function can be a big help under some circumstances [not all], and 
very occasionally, the manual NOTCH will make a difference.  Other than 
that, it seems letting my K3 do its job by itself, AGC on, RF max, AF 
for volume, works best.

What am I missing here?

For the record, my K3/100 is pretty vanilla:  One Rx, "stock" filters, 
KDVR, KAT3.  I have several locals within 3km of me, their rigs are very 
quiet on CW, they are the only signals that get much above S9+20, and I 
can get well within 1 KHz of them in contests and still work the weak 
ones.  They haven't complained, I hope I'm not getting too close :-)  I 
don't operate SSB a lot, usually only in contests to support my contest 
club.  If that's what this is all about, I apologize for the BW.  If 
it's CW, I'm either missing something or I guess I'm less discriminating 
that most.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2011 Cal QSO Party 1-2 Oct 2011
- www.cqp.org