[ARC5] BC-946 capacitor plates shorting?

[Tim]

Yep - What Tom said.... Also, my GRC-9 does the same thing occasionally.
Found to be tin whiskers growing in the apparent tin plating of the cap
plates.  Business card or pipe cleaners first, then a blast with compressed
air removes them.  A few microns in diameter, hard to see, but the ohmmeter
can't be fooled...  In my set they shorted out the local oscillator cap at
some rotational positions..
Some real physics "bugga bugga" going on there.  A known problem with tin
in electronics....
Give it a try..
Tim
N6CC

On Tue, Nov 9, 2021 at 2:18 PM Waldo Magnuson via ARC5 <arc5 at mailman.qth.net>
wrote:

> Hi,
>    I trying to get my BC-946 operational, capacitors replaced, etc.  I
> suspect the tuning capacitor plates are shorting because at the top end of
> the band I receive a station (Sacramento, CA from Spokane, WA) and at the
> bottom of the band a local station.  When I tune up, or down, it mostly
> goes quiet except for scratchies (is that a technical term?) noise.  On
> close inspection one of the rotor plates may be touching a stator plate,
> hard to see and tell.
>    Any fix suggestions would be appreciated.  Removing the gang capacitor
> looks messy.
> Skip Magnuson W7WGM
> Spokane, WA
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