[R-390] Advice Please

[Larry H]

Hi  Mack,  That would be my choice to check, but first make sure that the
BFO is adjusted correctly and that the KC change knob is adjusted close to
the center of the '0 adjust' range.  Are you using the built in
calibrator?  Does it cal at 3.9mc?

Regards, Larry

On Wed, Oct 7, 2020 at 11:58 AM Mack McCormick <w4ax.mack at gmail.com> wrote:

> I have a R-390 (non-A) and a R-391. Both work great but the R-391 cannot be
>  adjusted using the zero adjust on 3885 Kc. It is 3 Kc high (3888 Kc). It
> can be zero adjusted at 10 MHz.
>
> The R-390 can be zero adjusted perfectly on both frequencies. Since the
> R-390 is accurate I removed the 1st and 2nd oscillator module and placed it
> in the R-391. It still will not adjust on 3885 KC (Still 3 Kc high). So
> that really only leaves the PTO in the frequency accuracy chain.
>
> Do you recommend loosening the set clamp on the R-391 PTO and tweaking it
> slightly as recommended in the manual? Is there something else I should
> investigate and try?
>
> Thanks in advance for any ideas. I’ve rebuilt over a dozen R-390A’s and I’m
> very familiar with them but new to the non-A series.
>
> 73,
>
> Mack
> W4AX
> --
>
> 73,
>
> Mack
> W4AX
> https://www.qrz.com/db/W4AX
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