[Milsurplus] Advice Please: Frequency stabilizing a 80M ARC-5 transmitter

[Mack McCormick]

Mark and Robert,

Thank you for your suggestions.

Mack
W4AX

On Tue, Nov 8, 2022 at 13:30 Robert P. Meadows <rpmeadow at bellsouth.net>
wrote:

> Take a look at the Central Electronics VFO made from an ARCr/BCxxx
> Transmitter.  Problem was solved a good while ago.
>
> R
>
>
>
> *From:* milsurplus-bounces at mailman.qth.net <
> milsurplus-bounces at mailman.qth.net> *On Behalf Of *Mack McCormick
> *Sent:* Tuesday, November 8, 2022 10:41 AM
> *To:* milsurplus at mailman.qth.net
> *Subject:* [Milsurplus] Advice Please: Frequency stabilizing a 80M ARC-5
> transmitter
>
>
>
> I have an ARC-5 transmitter that I am using as a VFO for the BC-375 to
> prevent FMing from the BC-375 MOPA oscillator/PA.
>
>
>
> The ARC-5 exciter is working great except for frequency stability. The
> peak carrier frequency starts about 1 kc low and after about 1 minute is
> about 1 kc high. Not really a big deal except it drives the SDR folks crazy
> when I'm on an AM net.
>
>
>
> The 1626 oscillator is exceptionally well regulated using a FET in the
> external power supply. It is rock solid.
>
>
>
> *Do you have other ideas on how I might further improve frequency
> stability? *I built a crystal oscillator but it does not have enough
> drive using a 12A6 vacuum tube to drive the 1625's above about 5 watts. I'm
> still troubleshooting this circuit.
>
>
>
> I need about 20 watts out of the 1625s.
>
>
>
> 73,
>
>
>
> Mack
>
> W4AX
>
> https://www.qrz.com/db/w4ax
>
-- 
73,

Mack
W4AX
https://www.qrz.com/db/w4ax
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