[Elecraft] K1 alterations..and problems.

[Ron Willcocks]

Hi all,
         This might not be of much interest, but I found the exercise quite
enlightening...
I have a K1 here and the original Filter board was set for 80/20. I later
ordered a board for 40/17, and soon after was given a board for 40/20 .
Yesterday, I decided to rearrange the boards to be a bit more "user
friendly"  and I stripped  the unwanted RF components out of two boards,and
then built up one  board with 80/40 and another with 20/17m.
Sofar so good.
The 20/17 board tuned up no problem, but the 80/40 board worked fine on 80m
but refused to work on 40m properly.
On that band I had weak receive and transmit would show .1w.
Everything looked fine, so I had a decent go at fault finding this morning,
and by using a pretty basic fault finding technique, deduced that L5 in the
BPF wasn't tuning how it should. I removed C17, and before replacing it,
tried it in my Cap meter
to see what it was like. It read around 250pf. where it should have been
560pf. Replacing it made the filters tune up and I had good output.
Anyway......the moral of this story is. The part that went crook looked
fine, and it worked fine in the previous setup it was installed in, but
somehow it lost a lot of capacitance during the removal/replacement process.
It would appear that anyone trying a revamp like I did would be well advised
to use new components...for what they are worth!
Incidently the cap was one of those wee blue jobs.
Cheers......Ron ZL1TW
K1 #575
K2/100 #2204