[Elecraft] [K2] Odd AGC problem with K60XV installed

[Don Wilhelm]

Bill,

It does sound like it is fixed.  Just be aware that some intermittents 
do find their way back, so knowing the symptoms you can recognize it 
quickly.

73,
Don W3FPR

On 12/6/2020 6:30 PM, Bill Coleman wrote:
> Don,
>
> I set the K2 up this weekend to try to reproduce this problem. Once again I opened it up and re-installed the K60XV board. I put a scope probe on P1 pin 6.
>
> I did not see the AGC failure mode right away, but I did find an intermittent oscillation on pin 6 at about 15 MHz. It would come and go, but no AGC activation.
>
> I removed the board and re-soldered all the components around the LM358. Then I inspected the board and scraped away any residual solder flux in that area of the board between any pins.
>
> I also re-soldered the 4.0 MHz resonator, although I did not hear or detect any relay activation when it failed before.
>
> After that, I put the board back in with the scope probe and ran it on the workbench for a day. I saw no AGC failure mode and no more 15 MHz oscillation.
>
> So, maybe it is fixed? Fingers crossed.
>
>