I had a similar problem with a Swan Astro rig. In that case the trouble was
caused by an internal potentiometer which was used to balance the offset
when the offset tuning was turned off. Best my old memory can dredge up,
the pot was dirty and the dirt caused it to be misadjusted. The Astro was
indeed a puzzlement to me for a while.
It appears the Corsair II has a similar configuration. The Control Board
80978 is described on page 3-31 of my manual. Note paragraph four about
"the offset tuning zero adjustment" which is accomplished by properly
setting potentiometer R12 on the Control Board.
Good luck and 73,
Mike Hyder, N4NT
----- Original Message -----
From: "Steve Berg" <firstname.lastname@example.org>
Sent: Friday, July 16, 2010 10:46 PM
Subject: Re: [TenTec] Corsair II Frequency Drift
> Tonight while enjoying a nice CW ragchew, the other OM told me that my
> rig was changing frequency about 100 HZ when keyed. I have never been
> told this before, so I experimented a bit, and it looks like that
> happens according to the display. The counter shows an increase in
> frequency when keyed of about that amount. It seems to do it with both
> the internal PTO and the external VFO. I have checked, and the offset
> is switched off. Does anyone have an idea of what is happening here?
> Steve WA9JML
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