Hello there,
As being a long time TT fan (1979 Omni B es visit to their plant in
1982) I now wud like to share 2 problems I hve wid mi OMNI 6 + .
This to try to avoid to ship the rig (tempory export/re-import with al
the costs) to the factory; hopefully just an exchange of one or more
boards. Subscribed on this reflector last spring (Birth of ORION hi );
this is mi first entry on this list though.
In march I noted for the first time the problem that mi OMNI wud not
rcve ham sigs anymore but broadcast sigs instead of that (in particular
on 30m). Also transmit sig was not in hamband segment anymore. I wrote
amongst others to TT in all my "innocence" that suddenly mi SWR
position on the 238 tuner (fb tuner!) showed forward power. I now know
it is just a bad SWR.
Same day !!!! Paul WD4EBR replied as follows :
Dear Harry:
Have you checked your power supply? Is the power supply voltage constant
under a 20 amp load?
It appears that you have damage to diodes on the low pass filter board
and the metering circuit on the 9 MHz board. The LM358 that runs the
meter is probably bad as are associated switching diodes. This problem
is usually caused by a large static discharge or RF into the antenna
connector.
Since I was dependent on help from Jan, PA0SIM a friend it took a while
before the next action was taken es "results" were mailed May 26. (we
preferred to check the 5.0 - 5.55 Mhz PLL board first) Most relevant in
that 26th of May mail :
- On the second day we had a Gen coverage receiver and griddipper
> available and measured amongst others the output frequencies which
> are generated by the rig when it is in the "faulty" condition. We
> turned the VFO of the OMNI to the lower/upper bandedge of each band
> and found following results :
>
> 160 m - display 1770 - transmitted frequency 1.530 Mhz < 240
> 80 m - display 3470 - transmitted frequency 3.230 Mhz < 240
> 40 m - display 6820 - transmitted frequency 6.580 Mhz < 240
>
> 30 m - display 9970 - transmitted frequency 9725 Mhz < 245
>
> 20 m - display 14530 - transmitted frequency 14775 Mhz > 245
> 17 m - display 17970 - transmitted frequency 17725 Mhz > 245
> 15 m - display 21530 - transmitted frequency 21775 Mhz > 245
> 12 m - display 25030 - transmitted frequency 25275 Mhz > 245
> 10 m - display 28530 - transmitted frequency 28775 Mhz > 245
>
>
Again the next day !!!!! we rcvd Paul's reply :
It seems that you missed my first advise on the problem with your Omni.
Have you checked the diodes in the bridge circuit on the low pass filter
board? It appears that you are now looking in the wrong place to solve
your problem. If the Omni was as far off frequency as your chart
indicates the PLL could not lock and the Omni would neither transmit or
receive. Again, you need to look at the diodes on the low pass filter
board.
We then removed the 5.0 - 5.55 Mhz PLL board es checked all solder
connections; nothing found es then planned to check what Paul advised.
By the way after a while the set "recovers" es I can agn transmit es
receive in the hambands. Normally after 2 or 3 hours of
receive/transceive operation the set goes back in the "faulty mode". It
looks as if the PLL does not lock anymore es somewhere there is a
temperature dependent problem.
Before doing what Paul advised so checking the low pass filter board,
some months passed since we had a lot of other ham related priorities.
Hi
Before doing that diode check finally however the 2nd problem occured
early november : the ALC does not flash regularly in particular on the
bands > 20m when the output power is set to > 5 watts (average) es the
transmitted signal is "disabled" (wah wah sound) . It seems the ALC
limits output power in particular on high CW speed. (slow CW on 80m for
instance with a straight key is oke). This 2nd problem has not been
reported to TT yet.
The serialnumber is 02A10268 (bought in Germany from Zico Funk may 1980)
There is no voltage drop in mi PS by the wasy; vy satisfied wid the
service (responses immediate) ; once Ten Tec always Ten Tec !!!
I always loved mi OMNI es will probably never sell it also not when an
ORION will be in the shack sometime in 2003 I hope hi
All comments/advises are vy vy welcome
73
de
Harry
PA3ARM
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