[Elecraft] Fixing partially deaf K2.

[Kevin Cozens]

Bruce Bowman wrote:
> Just curious... did you ever get this resolved?

I'm not certain yet. Since my original message, I have dropped my AGC voltage 
to 3.98V, re-adjusted L34, and recalibrated the filters using the most recent 
notes for using Spectograph, and recalibrated the S-meter.

When I connected the K2 to an external antenna on Saturday night, the K2 
seemed to be hearing some stations in the DX window of 80m about as well my 
Grundig Satellite 800 shortwave radio (which was just using its built-in 
whip). The results are promising but I need more time to listen to stations 
and compare to my shortwave receivers.

While turning the slug of L34 clockwise, the internal signal peaks. Turning it 
a bit more and the noise to the right of the internal signal begins to drop. 
About the time it drops the slug appears to bottom out. I am wonders if I may 
need to change a cap around L34 to bring the point of best S/N ratio to 
somewhere more in the middle of the slugs travel range.

I didn't get any response to whether 2.5V rms on TP1 when the rig is tuned to 
80m is withing the expected range or not. For now, I will just have to assume 
it is.

I still think I am getting more of a change in audio level between AGC on and 
off than I should. To see if the 8V regulator output is causing the problem 
may require replacing the regulator. I'm not yet sure what voltages/parts I 
should check in the IF amp or AGC circuit to determine if there is a problem 
with one of these circuits.

Now that the receiver seems to be performing a little better, I will move on 
to the transmitter. I want to retest the amount of maximum RF I can get from 
the radio on the various bands and see if the change in VCO output has made 
any noticeable change. I will also be rewiring T1 and T3 as I don't think they 
are wound as well as they could be. They could be the cause for the slightly 
lower RF output (barely 10W) on 10m.

-- 
Cheers!

Kevin.

http://www.ve3syb.ca/           |"What are we going to do today, Borg?"
Owner of Elecraft K2 #2172      |"Same thing we always do, Pinkutus:
                                 |  Try to assimilate the world!"
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