The dry pto grease can cause that problem but if you don't think that's it,
your going to have to use either a frequency counter or another receiver to
monitor each of the 3 oscillators to find out which one is changing. You
have the xtal oscillator, PTO and bfo to check. The frequencies for the xtal
osc are listed in the manual and range up to 41mhz for 10 meters. The PTO
runs around 5mhz and BFO around 9mhz. Using another receiver, you could
couple it's antenna input to each osc with a hank of wire and listen to see
what's happening.
Happy tracking.
Steve Ellington N4LQ.
----- Original Message -----
From: <wb5jnc@juno.com>
To: <tentec@contesting.com>
Sent: Saturday, November 16, 2002 7:57 AM
Subject: [TenTec] Delta frequency shifts on TX
> Greetings all,
>
> I have been hearing a random frequency shift on transmit from my dad's
Delta 580 during our contacts on 40M CW. The pitch of the received signal
will shift down several hundred hertz (estimated) for a few characters every
so often and then go back up. It has to be from his transmitter because the
background QRM doesn't change pitch and another op in our roundtable has
noticed the same thing I'm hearing. My first thought was the PTO needing a
"lube job" but it seems too consistent for that -- it never shifts during a
character, apparently only between, and the amount of the shift stays
consistent. I'm now more inclined to think something in the TX switching is
the culprit, like it is sometimes picking up the sideband offset instead of
the one for CW. Anyone else out there ever encountered this? (Also I don't
think he has an external VFO for it, so I can't blame it on that.)
>
> TNX/73, Al
>
>
>
>
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