I wondered if 5/9 scheme might be the case. Then if it's not the PTO it's
got to be the other guys!
On Jan 20, 2015 4:09 PM, "Lee WA3FIY" <wa3fiy@radioadv.com> wrote:
> There is no 20 meter heterodyne oscillator in the Corsair II (or many
> other Ten-Tec's of that
> vintage). On 20 meters the 5.0-5.5 Mhz PTO is directly mixed with the
> 14.0-14.5 Mhz
> incoming signal to produce the 9 Mhz receive IF. The BFO oscillators come
> into play on all
> bands but since 20 is the only band where Dwight is having the problem,
> that pretty much
> rules out the BFO leaving the PTO as the primary suspect.
>
> 73,
>
> -Lee-
>
>
> On 20 Jan 2015 at 13:31, Katz Ajamas wrote:
>
> > >
> > >
> > > From: Dwight Orten <dwightorten@gmail.com>
> > >
> > >
> > > My I been working PSK with my old Corsair and I am starting to have
> > > trouble on 20 meters. Watching the waterfall, the incoming signal
> > > drifts off and my software can,t decode it. Sometimes it comes
> > > back, sometimes I have to chase the signal. I don't know if it is
> > > doing the same on transmit. The frequency readout is not showing
> > > any change when this happens. On all other bands the waterfall
> > > lines are straight as an arrow and no trouble coping. The PTO has
> > > never been rebuilt, but it seems to me if that was the problem it
> > > would be on all bands. Any thoughts, anyone? KM4FO Dwight
> > >
> >
> > Dwight-
> >
> > I don't know the Corsair but based on it's age... Perhaps component
> > value changes.
> >
> > In some of my older tube gear it has led to poor stability of a
> > heterodyne xtal oscillator. You can check if you have another RX you
> > can lay an small antenna near to and tune to the freq of the
> > heterodyne osc for 20m to check stablity.
> >
> > Maybe you are working a bunch of drifty guys on 20 ;-)
> >
> > 73,
> > -Bob
> > ah7i/w4
> > _______________________________________________
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> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
> >
>
>
>
> ---
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>
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