[R-390] Frequency alignment R-391

[Mack McCormick]

Bill,

Thank you for the tip. A kind member of this list is sending me a
replacement crystal. Hopefully it is better than the one currently in the
radio.

Thanks again,

Mack
W4AX

On Mon, Sep 28, 2020 at 13:31 Bill Cotter <n4lg at qx.net> wrote:

> Mack,
>
>
>
> As a last ditch effort, you might try opening the
>
> crystal holder and adding pencil lead marks
>
> around the round crystal element. This might
>
> lower the crystal frequency by providing
>
> additional mass to the element. Keep adding on
>
> both sides until the desired frequency comes into view.
>
>
>
> I put crystals in a vice, pins clamped. Then, use
>
> a heat gun to melt the can sealing solder, and
>
> pull the can off with pliers.
>
>
>
> I also have a homebrew crystal test instrument
>
> that connects to a counter and simulates the
>
> correct pF capacitance for crystal "tuning".
>
>
>
> When you get it where you want it, seal her back up.
>
>
>
> Best wishes - 73 Bill N4LG
>
>
>
>
>
>
>
>
>
> At 10:49 AM 9/27/2020, you wrote:
>
> >I have a R-391 that is about 3 kc high on 4 Mc.
>
> >I’ve tried adjusting the 1st crystal
>
> >oscillator variable cap but that won’t move
>
> >the crystal far enough. The same is true at 3
>
> >Mc. Any suggestions? I have restored at least a
>
> >dozen R-390a’s to factory specifications. I
>
> >have several ideas I could try but want to get
>
> >the collective wisdom of this group 1st please.
>
> >73, Mack W4AX -- 73, Mack W4AX
>
> >https://www.qrz.com/db/W4AX
>
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>
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>
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>
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> --

73,

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