[Elecraft] K2 AGC problem- update

[R. Torsten Clay]

Here's an update on my AGC problem.

I checked again to see if I could hear the 2nd harmonic of the AGC xtal
osc at 10.136. Couldn't find a signal there.  I also measured the voltage
at U2 pin 1 (see pg 12 of Appendix E). There was very little change
(~0.1V)  going from no signal to a very strong signal.

I built a crystal oscillator (the circuit in the troubleshooting section),
and tested it on some 10MHz and 7MHz crystals I have- it worked fine. I
then removed X1 from the control board and put it in the oscillator. It
oscillated, but the frequency is 16.2906 MHz instead of 5.068MHz!

Any idea what is going on? Do I have the wrong crystal at X1? Mine is a 
low-profile type, labeled "S162ECSL" on the top of the can.

Torsten
N4OGW

> Subject: [Elecraft] K2 AGC problem
> 
> 
> > Hi all,
> >
> > I'm having a problem with my K2's (#3134) AGC. I've got everything built
> > up through the 40m rx tests.
> >
> > The problem is that the AGC is very weak. A signal that registers S9+40 on
> > my Omni VI only gets to about S3 on the K2, and is painful to listen to
> > without turning down the gain manually. I have set the AGC voltage to spec
> > and calibrated the S-meter, but somehow don't get enough AGC action.
> >
> > Any suggestions on how to troubleshoot?
> >
> > Torsten
> > N4OGW
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> 
>