[Elecraft] K2 deaf on 20m, other bands OK

[Christoph Rheker]

Hallo friends,

I am having an issue with my K2 on 20m which
I finished a few days ago.

It's very unsensitive on 20 only, stations that are S9
on my Kenwood are only S3 on the K2. Also they
sound much weaker. When I connect my antenna
there is also no atmospheric background noise,
even when Pre-Amp is on.

It is only 20m that is affected, 10m is even
better than my Kenwood. 

30m is also OK. Since 30m uses the same band-pass
and low-pass filters as 20m I think the filters 
are OK. I checked C19-C25 and C197-C203 and all
is fine. Also re-soldered L18-L20.

I could not find the place where the signal is lost
with my little Oszi. But maybe I am looking at the
wrong place.

Another strange thing on 20m is: The Power Output
goes down a lot and the band end. When the K2 is
adjusted per the book on 14,100 kHz I get abt
15W there. But on 14,300 kHz I get a few watts
only! As if the band-pass filter is very narrow.

Hmmm. 

I am a little clueless now. But it is a rainy
Sunday, so plenty of time for fixing bugs :-))

Many thanks for ideas and 73,
Chris, DL4YAO