[Elecraft] [K2] Excessive PSK IMD with new K2/100

[Don Wilhelm]

David,

The KPA100 can be coupling back into the KSB2 option.
Remove the right side panel and tuck the ribbon cable and speaker cable 
up into the space at the top of the KPA100 instead of letting it dangle 
near the KSB2 board.

I will not guarantee that it will help, but it often makes a difference 
on SSB, and can also help on data modes.

73,
Don W3FPR

dberkley wrote:
> Just built a KPA100 for my K2 S/N 6274.  When originally running PSK on the
> barefoot K2 had no problem achieving IMD around -30 dB (measured with
> PSKmeter).  The K2 had a KAT2 tuner which was removed, and replaced by an
> external autotuner when the KPA100 was installed.
>
> With the new KPA100 in place I can't get the IMD below about -24 dB and it
> seems to be independent of power setting or actual output power (including
> bypass mode at 5 watts which is where I set the original K2) and remarkably
> independent of audio drive, which wasn't true with original K2.  There is a
> broad minimum in the IMD when the ALC barely flickers on the 3rd bar. 
> Optimal performance is on 20m but there is little difference on other bands
> (when the audio is adjusted).
>
> Any thoughts on what has changed?  Is there any obvious way to improve IMD,
> although I guess > -20 dB is in the barely acceptable range?
>   
>