12m alignment failure, C44 &/or C46 dirty wipers?

classic Classic list List threaded Threaded
1 message Options
Reply | Threaded
Open this post in threaded view
|

12m alignment failure, C44 &/or C46 dirty wipers?

Paul-289
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


_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com