[R-390] Advice Please

[Mack McCormick]

Thank you to everyone who responded to my query. I checked the PTO end
point calibration, moved the dial adjust to the mid-point of its range,
loosened the PTO coupler, and moved the PTO shaft about 1/8 turn.  All is
good now on all bands. Accuracy is perfect.

Thank you to everyone for confirming my plan.

73,

Mack
W4AX

On Thu, Oct 8, 2020 at 01:22 Larry H <larry41gm at gmail.com> wrote:

> 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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> --

73,

Mack
W4AX
https://www.qrz.com/db/W4AX