If he only works 40 meters, his bandswitch contacts may need cleaning.
Suggest that he fully rotate his bandswitch end to end about 10 times. If
his rig hasn't had its switches lubricated in a long time, it might help to
clean and lubricate them, but just rotating the bandswitch may help.
73, Mike N4NT
----- 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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