Soooooo...... maybe I am totally off BASE, but if the "master" oscillator is
the issue, wouldn't he be noticing the problem on all bands, with going higher
in frequency getting worse??
73-
Greg, KC8HXO
--------------------------------------------
On Mon, 7/4/16, Peter Klein <pklein@threshinc.com> wrote:
Subject: [TenTec] Omni VI instability, TCXO worth it?
To: tentec@contesting.com
Date: Monday, July 4, 2016, 8:14 PM
I queried service@tentec.com
by email about the following issue last
Tuesday. I have heard nothing so far, so I thought I'd get
some advice here.
Background: I live in the Seattle area. I have modest
wire and vertical
antennas. I'm not a contester or hard-core competitive DXer.
I do try to
work DX when I can, and I might jump into a contest to snag
a new
country. But mostly I do HF digital (PSK, Olivia, MFSK),
casual CW, or
occasionally SSB.
I've owned my Omni VI for 20 years. It has the Option 1 DSP
upgrade.
Over the years, the radio has several times developed a
frequency
instability issue. Over a time ranging between less than a
second to a
few seconds, the transceiver moves a few 10s of Hz off
frequency, then
"snaps" back. It's mostly done this on 30m, occasionally on
20m, and now
on 40m. Lately, it happens on 40m, with a short "period," so
if I am
listening to a good, pure CW signal, it sounds like it has
old-fashioned
"chirp."
The frequency shift occurs on both transmit and
receive. When it
happens, if I switch to another band, it does not happen
there. It is
intermittent. Sometimes it appears random, and sometimes
appears
temperature-related (for example after transmitting for a
while, or if
the radio has been just turned on in the last half-hour or
so).
When it first happened (1997), Ten Tec Service advised me to
tweak the
trimmer coil to the 30m mixer crystal 1/8 to 1/4 turn in
either
direction until the "drift and snap" stopped, and just live
with the
slight display error. I did, and later did the same thing to
the 40m
coil when that band acted up. It worked in both cases.
When it started to do the frequency dance on 20m, I sent
back to the
factory for a tune-up. This was in October 2013. Now, it's
doing it
again on 40m.
I spoke to TenTec's service manager a few months ago. He
said that the
problem might be solved by installing a temperature
compensated crystal
oscillator (the TCXO was never suggested before). He
said that I could
install this myself if I could solder a couple of wires. He
quoted me a
price of $200 to send me the necessary circuit board and
instructions.
He said it was up to me whether I wanted to spend $200 on
"an older
radio." He was also dead-set against my tweaking the
trimmer coils to
the individual band crystals.
I decided to wait and see if leaving the power supply on
24/7 would
solve the issue. Nope. And while I was waiting, Ten-Tec was
sold and has
new service policies.
I would like to install the TCXO, *IF* it is very likely
that it will
solve the problem, and I can get at least another couple of
years of
good service out of the radio. On the other hand, the
radio is 20 years
old. So if it's just as likely that I will continue to have
the problem,
then maybe the TCXO isn't worth it, and I should think about
a new radio.
So, what would you do if you were me?
Thanks and 73,
--Peter, KD7MW
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