Have you tried a master reset of the microprocessor? I believe the offset
between the 5 Mhz VFO and the display changes with modes, CW pitch,
etc. Maybe something got scrambled in the NVRAM.
Keep us posted. (I have a wonderful Omni VI/3 here as well. :-)
73,
-Lee-
On 4 Sep 2008 at 15:54, Steve Hunt wrote:
> I can't remember if I've raised this problem before; if I have, I apologise!
>
> My OmniVI frequency readout is consistently 130Hz high on all bands and
> all modes; in other words if I accurately tune in a station on 14,200KHz
> the frequency read out will be 14,200.130.
>
> I've adjusted all the BFO settings and the TCXO setting as accurately as
> I can with a frequency meter whose calibration I checked against a DDS
> source zero-beated to WWV.
>
> Here's what's puzzling me:
>
> 1) I'm reluctant to suspect the BFO frequencies - it's too much of a
> coincidence that USB, LSB and CW are all out by exactly the same amount
> in the same direction. In any case they are within 5 Hz as measured on
> the counter.
>
> 2) If the TCXO was out, I would expect the 5MHz VFO, the Xtal
> frequencies, and the final LO frequency all to be out by the same
> percentage. That would result in approximately 3 times the frequency
> error on 10m as on 160m; but I see the same on all bands.
>
> 3) Interestingly, I recently swapped the oven oscillator for the TCXO.
> The same 130Hz shift was there before and after the change. Again it
> seems too much of a coincidence that the two reference oscillators were
> out by exactly the same amount. I needed to make a very small adjustment
> to the TCXO to get it on 20 MHz, but that had no effect on the "offset".
>
> I could always deliberately "misadjust" the BFO frequencies to
> compensate, but that seems a retrograde step and would likely alter the
> Tx audio characteristics by moving the carrier relative to the filter
> skirts.
>
> I can't think of anything that would produce the same offsets on all
> bands and all modes. Am I missing something?
>
> It's not a showstopper - just an annoyance.
>
> 73,
> Steve G3TXQ
>
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