If it were my rig, here's what I'd do:
1. with drive at minimum, I would turn the rig to tune or key it on CW.
2. then I would watch the current drawn by the rig as I slowly advanced the
drive control.
3. if there happened a sudden increase in the current, I would shut it down
immediately. That would be an indication that the final amplifier (or the
driver/final combination) was oscillating
Since those rigs will oscillate in the final if they do not receive proper
ALC voltage AND a self-oscillating final has outputs everywhere, there is no
way to ever match an antenna.
The diodes that generate the ALC are on the same board as those which
develop the SWR meter current. They sometimes fail if the rig is connected
to an antenna when a lightning storm is within maybe a mile. If you do see
a sudden increase in the current, I suggest you just replace all four of
those diodes and if there is a fifth in close proximity, change it too.
Please advise the group if you are successful in repairing your rig.
73, Mike N4NT
----- Original Message -----
From: <tubsc66@aol.com>
To: <tentec@contesting.com>
Sent: Friday, September 10, 2010 6:43 PM
Subject: [TenTec] Omni D issue
Hello everyone, my Omni D has developed an issue that puzzles me (not hard
to do...:), it has developed a
high-swr issue that none of my other rigs have (I have other TT's and
riceboxes), same antenna, autotuner
and feedline. The autotuner is unable to find a match unless the output is
very low. When releasing the
mic (PTT), there is a delay in the receive signal coming back to full
strength, it is
accompanied by a "click", which must be the T/R relay sticking. Could the
relay cause such an
issue? I thought swr issues were dependant on the antenna, not the radio.
Anyway, I'd like to
fix it, any thoughts out there? Thanks!
73's
Chris KC5IIE
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