[TenTec] Omni VI+ S meter troubleshooting

[John Hodge]

I have an Omni VI+. You could put an analogue test meter across the S meter coil. This would do 2 things: check the meter coil resistance and cause the needle to deflect.

John G8CCD

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On 17 Nov 2018, 04:41, at 04:41, Phil Erickson <phil.erickson at gmail.com> 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
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