Steve Jones wrote:
>
> I have heard alot of rumors about the frquency drifting on the Omni VI
> series radios, is this fact or fiction. I would appreciate any and all
> replies and 73, DE-KS4HK, Steve
> jsjones@rbnet.com
>
Yes if you consider 40 cycles of warm-up drift a problem. Most of the
drift I've experienced occurrs in the BFO. The trimmer for this is
very fickle to adjust and tends to get out of adjustment causing
a frequency offset problem. The result is not being able to properly
get on the other station's frequency. This is a fact of life for all
TenTec rigs that I've used. The trimmers seem to need either cleaning
or replacing after a few years. Believe it or not, I cleaned one with
WD-40 and after a day of "drying off" it turned out the be the
smoothest,
most stable trimmer I've seen yet.
Another source of drift is the master oscillator in the processor which
also has a very sensitive trimmer. I use WWV to calibrate this but you
need a steady hand. This xtal osc is temperature regulated as long as
the rig has 12v applied. Otherwise, expect about 20 or cycles of drift
from this.
I believe the Company considers less than 50hz drift to be acceptable.
Whether it is or not is up to you. Personally, in 1997, I would expect
better stability. I'm willing to put up with it in order to enjoy the
good receiver. Others may not be inclined to do so. To me, the worst
side effect of this is being off frequency with other stations. This
is not only annoying but uses up extra band space.
I know some out there will say " who can even hear the difference in
50hz"? Well, a lot of us can and it's not just 50hz when the trimmers
get out of wack. It can be as much as 200hz. This weak point needs
attention IMHO. Not being an engineer, I'm not sure what the cure is.
Perhaps higher quality trimmers? The trimmers in the JA rigs seem to be
more stable and smoother in operation. You can take 2 IC-706's, set them
to display 1 cycle, set the dials to the same frequency and you'll be
dead on frequency. I used to use my 706 to set the oscillators in the
Omni-6. All that was need was a short piece of wire for an antenna on
the
706. Just toss it inside the Omni and listen for each oscillator. Adjust
the trimmers and you're good for another 30,000 miles. The 706 was
always within 2hz of WWV.
While we are on the subject of weak points. Being a long time cw op, I
can spot an Omni-6 by ear. The keying has a hard sound upon key closure
and there seems to be just the slightest frequency variation, dare I say
chirp? It's a bit tiresome to listen to when you're on the other end.
Don't get on my case because many others have noticed this too. I even
heard one of TT's own boys using a new 6+ with the same twirpy sound.
How about looking into that guys?
Hope I didn't upset any of you guys who's XYL wears TenTec shirts to
bed. I'll leave this alone...... By the way, I've got a Paragon, Omni-5,
Hercules 2 and 238 tuner.
So far, nothing I've found is more satisfying for cw.
73 N4LQ Steve.
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