[TenTec] intermittent OmniVI rx problem

[Don Jones]

Don't be too quick to blame the "6".
Much to my sha-grin I discovered a problem with my "6" was actually a
problem with the bypass contacts of T/R relay in my Clipperton L RF Power
Amplifier.
I recently purchased a MFJ Auto tuner for use with my "6". 
I wanted of course to check the tuning range of it so I hooked it up
directly to my 20M Double Extended Zepp and began "tuning the bands" to see
if there was a freq the tuner did not like. I did not bother with 160M.
Anyways I settled in on the 4A4A DX-pedition on 40M and was listening to
them run their CW pile up. 
At that point I decided to re-connect my "6" back thru the amplifier, next
thing I knew 4A4A was down 4 to 5 s-units and copy was poor.
I immediately swapped back to direct connection to the antenna (thru the
auto tuner) and the copy was restored to 589.
I have seen amplifier T/R relays fail on the transmit poles, but this was
the first failure I have encountered on the bypass (receive) poles of a T/R
relay. 
Since you said ARRL DX Contest, I wonder if you are using a amplifier and
you might be having a similar problem?
73,
Don Jones 
Arlington, WA 

-----Original Message-----
From: Allan Taylor [mailto:k7gt.cw at gmail.com] 
Sent: Saturday, March 12, 2011 7:51 AM
To: tentec at contesting.com
Subject: [TenTec] intermittent OmniVI rx problem

My OmniVI/opt3 has a receive problem. It will intermittently drop down
in received signal level by 5 or 6 S-units. This dropout stays for
long periods of time yet is intermittent for sure. There are still
signals coming through, but it drops down enough to clearly hear hiss
from the IF stages. It was doing this over a year ago and got an
all-expenses-paid trip to TT service. Once back there, it, of course,
went away and TT couldn't find anything wrong. Net expense: ~$275.
That rig sat for most of the past year (I was using either the K3 or
MP in the meantime). I finally put it on the air for ARRL DX/CW last
month. It behaved for about 5 hours, then dropped out for a few hours,
then back, then gone and has remained gone.

I suspect an inter-module connector is not quite making contact  or
perhaps the reed T/R relay has failed.
What would a failed T/R relay sound like? Is there a most-likely
connector to check? Is there a best before/after
place to check, stagewise?

I am not an experienced debugger/signal tracer and have limited test
equipment. I love the radio. Please give me your best input!

-- 
73     Allan    K7GT