[Elecraft] More miseries on K2 #5061

[M. P. Haynes]

Hello again folks,

I seem to still have that black cloud hanging over me as I finish the
basic K2 #5061.  

I am finishing the calibrations and adjusting the L's and C's in the
bandpass filter section.  I had 1 1/2 problems remaining.  All the
circuits tuned properly in receive mode except the 30 meter/20 meter
bandpass filters.  They would not resonate no matter how I screwed the
slugs in or out or adjusted the trimmers on 20.  I took the unit to an
engineer friend (K4POZ, who retired from chief engineer for WSB radio in
Atlanta) and he verified that I had assembled the circuits correctly and
had no solder splashes or missed connections. (He recently completed his
own K2)  He noted that when the slug on L9 was all the way in, the signal
started an ever-so-slight increase in output.  Figuring the circuit was
resonant too high, he added a 39 pF cap across L9 and the signals could
then be properly tuned on 30 meters.  The trimmer C23 rotor plate had
come disengaged (popped out) as I had attempted to tune it earlier and a
new one was sent by parts.  I anticipated that would solve my last
problem but to no avail, so 20 meters is still down about 70 dB or more. 
I rechecked all components in the circuit and all are installed
correctly.  Has anyone ever seen this problem before?  Suggestions?  By
the way, I solder filled all the through-holes around this circuit just
in case there was a poor plate-through feed.  No change.

73,

Pat Haynes-K4BEH