----- Original Message -----
From: "John Buck" <kh7t@arrl.net>
To: <tentec@contesting.com>
Sent: Thursday, November 28, 2002 8:24 PM
Subject: Re: [TenTec] Omni VI Plus alignment without a freq ctr?
> I found that on my OMNI VI + mod 3, I was easily able to hear a beat
> note between the TCXO and the carrier of 10 MHz WWV.
>
> I used Spectrogram to sort things out and make sure that I was beating
> to the carrier and not one of the modulation tones.
>
> It may be necessary to attenuate the WWV antenna input to make sure that
> it does not overwhelm the TCXO signal.
>
> When the tcxo is within less than 10 or 20 Hz you can see the beat on
> the S meter.
> This "feature" allows you to adjust the TCXO to within a fraction of a
> cycle of WWV. One pulse per second is within 1 Hz of zero beat. 5
> seconds per s meter cycle is within 0.2 Hz. This method is as good as
> or better than using a counter and is limited only by the resolution to
> the TCXO adjustment.
>
> Only after making sure that the TCXO is accurate at 10 mHz. can you then
> proceed to adjust the BFO frequencies. I was totally unsuccessful in
> tuning the other oscillators and getting good audio on both sidebands
> until after the TCXO was properly tuned. Once it is tuned, do not touch
> it to compensate for errors in the BFO settings. This will just unravel
> your good work.
>
> I have a good HP counter but like the above method for tuning the TCXO
> better.
>
> Aloha,
> John KH7T
>
>
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>
I agree 100% with John's method.
The human ear is very good at picking out beat notes, furthermore this
method is MUCH faster and potentially more accurate than using a frequency
counter.
This is how I usually align the oscillators when I repair a radio, no
complaints yet!
Paul MW0CDO
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