Hi Mike,
Here's my final synopsis. There's more here than you'll probably ever need to
know. By the way, the info is also on the reflector from back in '09 when I had
the problem.?
http://lists.contesting.com/archives//html/TenTec/2009-10/msg00238.html
I suggest you compare my symptoms to what you're rig is doing and
if it's the same (or very similar), just go for the?jugular and hit ALL the
connections on the 5 mhz PLL board.?
Later, Joe
Radio Dudes: I figured I'd give you a final (I hope) synopsis on the
PLL/Synthesizer problems I dealt with recently. The info may come in handy for
someone, some day. By the way, thanks to those who steered me towards the PLL
board. Otherwise, my radio might still be broken. (or in Sevierville)
Symptoms:The display reads correctly. It even changes when you turn the VFO.
However, the received freq doesn't change. How did I know that? When I
changed bands to 160, I could hear an AM broadcast station. Turning the VFO
didn't change what I was hearing. Fixing it:It was suggested that I check the 5
to 5.5 Mhz output from the PLL. I didn't have a freq counter, so I used a
Tektronix 456B, which is a 200 Mhz scope. The output showed as 5.8 Mhz and it
did not change when cranking the VFO or hitting the up/down buttons. The 2
inputs to the board (10 Mhz clock and serial freq data) appeared to be good,
so I was pretty sure I was on the right track. NOTE: The output also h
ad what seemed like a low voltage level (1 volt p/p). I called Ten Tec about
the sig level, but they didn't know what it should be. (More on that later)
Another Ham who had PLL board problems strongly suggested that I re-heat
suspect connections on the board. I did this (in fact, I hit every connection
on the board) and the radio worked for 2 days. While it was in the working
state, I scoped the PLL output and saw it change with the up/down buttons. The
voltage level was 1 volt p/p in the working state, so I now knew that was
correct. For the next few days, the radio would work then not work. I tried to
"make it fail" with heat and cold, but those didn't seem to make a difference.
During this process, I made a few notes and drawings of various waveforms and
levels around the board. Unfortunately, 3 weeks have passed and some of those
notes don't make any sense to me now. Here are the ones that do: 1) At the
junction labeled "Test point" (duh...go figure) on the P
LL schematic: When working, and the rig set to 40 meters, it had a 100 mv
sine wave riding on a 325 mv DC level. (I forgot to record the freq). When
failing, it was nearly at ground potential (less than 15 mv), with no sine
wave. 2) At U4, pin 5, with the rig working, I saw 775 mv when on 40 meters. I
didn't record it in a failed state. 3) At R11 and R12, with the rig working:
You should see a 5 volt level, with negative-going spikes to ground, every 100
usec. 4) U5, pin 6, with the rig working: 133 Mhz signal. I can't remember if
it was square or sine. 5) U4, pin 7, with the rig working: 2 v DC 6) U4, pin
1, with the rig working: 3.5 v DC "Sometimes it's better to be lucky than good"
While beating on components to try make it work, I noticed that a slight tap
on L12 could make the rig fail or work. I re-heated the connections to L12,
(including L12's case to ground on top of the board) and the radio has been
fine since. That was over 2 weeks ago. I even got brav
e enough to put it all back together several days ago and it's still working.
Hopefully, it's been put to bed. Later, Joe
-----Original Message-----
From: Mike <w4mjr@att.net>
To: k8mp <k8mp@aol.com>
Sent: Wed, Nov 11, 2015 8:48 pm
Subject: Re: Ten tec omni 6+
OK Joe that would be great. I like my 564 and miss it when not in use. I
moved the Hercules II over to my ICOM 751A for the time being.? Ok Joe look
forward to your repair info. Thanks agn. Mike W4MJR
Sent from my ALCATEL ONETOUCH A564C
On Nov 11, 2015 7:33 PM, k8mp@aol.com wrote: You jogged my brain and yes,
that was me Mike. I fixed it myself with help from the guys on the Ten Tec
reflector.
It involved removing one of the boards (PLL board, think) and re-heating
EVERY connection (top and bottom) with an iron (and add new solder if
necessary)
I'll look over my notes and get back to you with the details, probably
tomorrow.
Later, Joe
Sent from AOL Mobile Mail
-----Original Message-----
From: Mike <w4mjr@att.net>
To: k8mp <k8mp@aol.com>
Sent: Wed, Nov 11, 2015 07:36 PM
Subject: Re: Ten tec omni 6+
602606e" Sorry Joe but I might have you mixed up for someone
else. I have a ten tec omni 6 plus and started losing audio sound. It would
come back in and then go back out. I could put it on the 160 meter band and
hear an AM station but could not make it out what they were saying.? I replaced
the 3 volt battery backup and did a reset but nothing changed. Anyway Joe I
have been reading so much about trying to figure out what was wrong before I
send it in to ten tec for repair.? Anyway I thought I had read on the
contesting.com about you and your omni 6 plus. I know it had to be an old
thread. I just didn't pay any attention to the date. If I have you mixed with
someone else problem I appolize.?????????????? Thanks, mike w4mjr
Sent from my ALCATEL ONETOUCH A564C
On Nov 11, 2015 5:14 PM, k8mp@aol.com wrote:
Hi Mike, Can you refresh my memory by
pasting the details into an email?
Thanks, Joe
Sent from AOL Mobile Mail
-----Original Message-----
From: Mike < w4mjr@att.net>
To: k8mp < k8mp@aol.com>
Sent: Wed, Nov 11, 2015 12:46 PM
Subject: Ten tec omni 6+
Joe I am having the same problem with me 6+ as you had
with losing the audio. This might be old stuff because I was just searching
thru the web and saw where you were looking for answer about your rig. Did you
get yours repaired and what was the cause.? Thanks, Mike w4mjr Sent from my
ALCATEL ONETOUCH A564C
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