[R-390] Calibrator tone every 90 Khz

[Jordan Arndt]

This is simply due to the calibrator being out of adjustment...setting it for
zero beat with WWV will solve the problem... 73 de Jordan....

Michael Murphy wrote:

> Hi Harold,
>
> Perhaps a Motorola feature? Did you rock C310 the crystal frequency trimmer
> to try and zero her back in? Do you run out of adjustment?
>
> The crystal oven could have failed and cooked the crystal. Of course, it
> could just be a bad crystal. Most likely, the crystal has aged badly and
> drifted down in frequency.
>
> Do you have a counter with a 10X probe that you can put on the crystal pins
> (octal pins 2 or 8 after removing the oven cover) to check for 100 kc? Do
> you have an old 100 kc crystal that you can plug in to the octal socket
> between pins 2 and 8?
>
> Next try swapping out the tubes in the calibrator.
>
> It also could be a cap or resistor failure in the circuit. This means
> pulling the RF Deck - much fun!
>
> My R390A calibrator had poor output - you could barely make it out on most
> cal points.
> I pulled my RF deck a couple of months ago when I was doing my general
> re-cap exercisce and replaced quite a few capacitors. I can report that
> several of the resistors in the calibrator, especially the plate resistors
> on the multivibrator were cooked and way off in value. I replaced R221, R224
> and R226 with 1Watt flameproofs.
>
> Wishes for a much happier calibrator
>
> Mike WB2UID
>
> ----- Original Message -----
> From: <hdalexander at att.net>
> To: "R-390" <R-390 at mailman.qth.net>
> Sent: Thursday, July 08, 2004 12:22 AM
> Subject: [R-390] Calibrator tone every 90 Khz
>
> > Hi All
> >
> > I have a Motorola R-390(non-A). The calibrator makes a tone approximately
> every 90 Khz., not every 100 Khz.. For example: 14000, 14090, 14180,14270,
> 14360. Do any of you have any words of wisdom for me? Thank you in advance
> for any help.
> >
> > Harold Alexander
> > Modesto, CA
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