Hello Reid.
It is normal for Balanced to need nulling periodically. In fact
all radios should be checked a couple of times a year. It
is just the nature of components to age slowly, and no matter
what, they will need touched up.
Most guys don't mess with it, but if you listen on ssb and tune
slightly off of zero beat, you'll find an awful lot of carriers less
than 30 dB down.
The easiest method and the most effective as far as I'm
concerned, is with a standard ssb receiver. Tune it in with the
microphone audio set at zero, listen to the beat and tune for
a null. You should actually hear the carrier disappear and be
replaced with a hollowy, wide hum.
It will take tuning both controls a few times as they do interact
with each other.
This is normal - standard old maintenance that all hams should
be doing with regularity.
Good luck.
de KL7HF
-----Original Message-----
From: Simmons, Reid W <reid.w.simmons@intel.com>
To: tentec@contesting.com <tentec@contesting.com>
To: <tentec@contesting.com>
Date: Wednesday, May 06, 1998 8:23 AM
Subject: [TenTec] Oh No!! I think it's broke!!!
> Hello TT fanatics;
>
> Has anyone out there done a "carrier null" adjustment on their Omni
>VI/3??
> Mine seems to be putting out carrier on LSB which, when the PTT (or
>the
> key) is first pressed, jumps up to at least 30 watts out before
>settling
> down to a lower but still present level. On a nearby receiver the
>LSB
> audio sounds great (similar to AM). This is frequency independent
>and into
> a dummy load. It does not do this on USB, but then the audio does
>not
> sound as good as LSB either. This is the first time I have tried
>using the
> Omni on SSB since I had option 3 installed many months ago (I was
>#140).
>
> I talked to TT service and they also seemed to think a carrier null
>was in
> order, and may do it for free since this may have occurred during
>option 3
> modification. Does anyone know why the carrier null would need
> readjustment since this board is buried deep within the rig and
>doesn't
> seem to have much relationship to the option 3 modifications done?
>
> I would prefer to fix it myself if possible as the cost of shipping
>and
> $2500 worth of insurance is rather steep from out here... not to
>mention
> the withdrawal symptoms of being without my Ten Tec for a period of
>time.
> Any help or suggestions would be greatly welcomed.
>
> My test equipment is modest: Tek 455 scope, DMM, signal generator,
>Bird 43,
> grid (FET) dip meters.
>
> Thanks.
>
> Reid, K7YX
>
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