[Elecraft] 12m alignment failure, C44 &/or C46 dirty wipers? Oops

[Paul]

Oops, after I sent this I realized variable caps don't have wipers like a
pot does. Oh well, still wondering why it suddenly started to function.

From:	Paul [pvasilauskis at charter.net]
Sent:	Sunday, May 15, 2005 11:46 AM
To:	elecraft at mailman.qth.net
Subject:	12m alignment failure, C44 &/or C46 dirty wipers?

Everything was going fantastic with the final alignment until 12m then
nothing. Only 0.2 indicated no matter how I adjust C44 or C46. Quick search
of the archives and a look at the schematics points to soldering, C44, C45,
C46, soldering, K6, VCO or soldering as potential causes. Pulled off the
bottom plate, got out the magnifying headgear and scrutinized every joint.
Beautiful joints, nice smooth fillets on both sides, even got out the
alcohol and cleaned 'em up a bit more. Checked TP1 at 24890 and got 19975.75
so the VCO is fine. Set to 24900, hit TUNE, still 0.2, tweak C44 a bit then
BAM 4.6, a few more iterations between C46, C44 and she's peaked at 2.1 as
requested by the power setting. So hummmm, could the wiper on C44 have been
dirty or something? I know I twisted both the full range when it first
failed. Interesting but happy ending. Hope this tid-bit may prove useful to
someone else.

73,
Paul
KI4BIO