[TenTec] Omni VI instability, TCXO worth it?

[rick@dj0ip.de]

Peter,

I personally would not do it.
If you can find a used one for $50 or less, then perhaps.

Hopefully someone here will have a few tips to enable you to keep using it
as is.

The TCXO was a nice but at this late stage, investing another $200 in a
radio that old is probably not a wise idea.

If you can't fix it, perhaps it is time to buy another radio.
The $200 is a good start towards that.
If you can sell it "as is", fine but otherwise you can part it out and sell
it on ebay.

I doubt a good option 1 will bring more than $500 these days and since it is
not working properly, it won't bring that.  


73 - Rick, DJ0IP
(Nr. Frankfurt, Germany)


-----Original Message-----
From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Peter Klein
Sent: Tuesday, July 05, 2016 2:14 AM
To: tentec at contesting.com
Subject: [TenTec] Omni VI instability, TCXO worth it?

I queried service at 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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