[TenTec] Omni VI+ S meter troubleshooting

Tue Nov 20 09:27:27 EST 2018

Remove the meter from the radio (easy).

Peel the front cover off (only Scotch tape holds it in place!).

With a jeweler’s screwdriver, turn the pivot tension adjustment screw 1/4 turn CCW.

Reverse the disassembly process.

From my personal experience, a lot of Ten Tec S meters suffered from this sort of binding, likely due to some damage to the wear surfaces. This simple adjustment corrects the sticking but is not sufficient to adversely affect meter operation.

Gary

W0DVN

> On Nov 20, 2018, at 8:23 AM, Phil Erickson <phil.erickson at gmail.com> wrote:
> 
> Hi all,
> 
>  Spent a few minutes more with the VI+.  I hooked it to a dummy load and
> keyed the transmitter in TUNE mode.  With the knob on FWD power, the meter
> did move in sync with the power being drawn from the DC supply (15-20 A
> depending on mode), so the meter movement appears indeed not to be
> completely dead.
> 
>  However, it's sticky.  On the FWD meter setting, when you raise the TX
> power and then turn it back down, the needle gets stuck midway on the dial
> and won't go down to zero.  Firmly tapping on the front face does
> eventually get it to zero out, and then you get one pass from zero to max,
> whereupon it sticks again when the power is turned down.
> 
>  Obviously this is not very useful.  Anyone know how to unstick or
> recondition this kind of movement?  Maybe there is some old-time collective
> wisdom I don't know about.  Or am I resigned to finding a new S meter from
> someone's surplus pile?  [If so, who has these kinds of surplus parts now?]
> 
> Cheers/73
> Phil W1PJE
> 
> On Sat, Nov 17, 2018 at 6:17 AM Phil Erickson <phil.erickson at gmail.com <mailto:phil.erickson at gmail.com>>
> wrote:
> 
>> Hi Jim,
>> 
>>  Thanks - already checked that part out with the S meter unplugged.  I
>> could adjust R25 through its full range and see the voltage on a DMM go up
>> and down, so the pot wasn't at a dead spot, but I could certainly see where
>> this might happen in other cases.
>> 
>> 73
>> Phil W1PJE
>> 
>> On Sat, Nov 17, 2018 at 12:51 AM <w3ka at lycos.com> wrote:
>> 
>>> Phil OM,
>>> 
>>>  I had similar issues with my TT Omni 6+.  S meter readings were there
>>> but extremely low.
>>> 
>>> On the IF/AF board, there is an S meter adjust pot, R25 a 1K trimmer
>>> control.  Mine was
>>> 
>>> sitting on a "dead spot".  Gently rock the pot up and down, (not too
>>> much, just enough to free the dead spot on
>>> 
>>> the trimmer).. World great on  my VI+ and resolved the S meter issues.
>>> Good luck
>>> 
>>> 
>>>                        73,  Jim W3KA
>>> 
>>> 
>>> 
>>> On 2018-11-17 04:41, Phil Erickson wrote:
>>> 
>>> Hi all,
>>> 
>>>  I've just acquired an Omni VI+ with all the filters including the Inrad
>>> roofing filters.  It is very sensitive as far as RF goes on all bands
>>> using
>>> a HP 8640B signal generator as a calibrated source.  However, the S meter
>>> does not work at all when AGC is enabled (or for that matter, when it
>>> isn't, although of course AGC should be on to generate a reading).
>>> 
>>>  I pulled the covers off and examined the IF/AF board.  According to the
>>> manual section 4-7, the voltage driving the S meter is at connector 58 (a
>>> 2
>>> pin one).  I pulled the connector off and, using a multimeter, was able to
>>> verify that a correct voltage was there on the pins in the ~200 to 800 mV
>>> range.  I was able to make that voltage go up and down as expected by
>>> manipulating  the RF gain, and also by changing the signal generator's
>>> amplitude.  The R25 and R29 trimmers also made the voltage move up and
>>> down
>>> as expected ("full scale" and "offset').
>>> 
>>>  So I think the S meter driving circuitry is working fine in RX mode from
>>> the IF/AF board..
>>> 
>>>  However, the manual is not clear on how the meter is multiplexed with
>>> the
>>> TX section, which I haven't tried yet as I'd like to get the receiver
>>> going
>>> first.  I tried moving the meter selector knob to a few positions, but of
>>> course all of those are for when the TX is engaged (FWD, SWR, Ic, PROC) so
>>> it did not help.
>>> 
>>>  Does anyone have suggestions?
>>> 
>>> 1)  Maybe the meter movement has failed?  If so, does anyone have any
>>> tips
>>> to isolate the meter and drive it with an appropriate voltage to see if
>>> the
>>> needle moves?
>>> 
>>> 2)  Is there any other check to see if the meter is somehow not paying
>>> attention on RX because it's stuck on one of the TX meter settings?
>>> 
>>>  3) Are there any other connectors to reseat?
>>> 
>>> Thanks in advance -
>>> 
>>> 73
>>> Phil W1PJE
>>> 
>>> 
>>> 
>>> 
>> 
>> --
>> ----
>> Phil Erickson
>> phil.erickson at gmail.com
>> 
> 
> 
> -- 
> ----
> Phil Erickson
> phil.erickson at gmail.com <mailto:phil.erickson at gmail.com>
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com <mailto:TenTec at contesting.com>
> http://lists.contesting.com/mailman/listinfo/tentec <http://lists.contesting.com/mailman/listinfo/tentec>