For those that have one of the "smart phones" I suggest the free app
Cateater Tuner. It reads out in 0.1 Hz. Just set it next to the radio, let
it hear the CW note and adjust the tuning for your sidetone frequency. It
also generates a very nice sine wave signal too. If you use the F5 musical
note it is 698.5 Hz. I find the accuracy to be +/- 0.5 Hz.
73
Bob, K4TAX
----- Original Message -----
From: "Ken Brown" <ken.d.brown@hawaiiantel.net>
To: <tentec@contesting.com>
Sent: Sunday, October 19, 2014 8:27 PM
Subject: Re: [TenTec] OMNI-VI question
If one has (or has access to) a synthesized signal generator, that can be
set to the exact desired BFO frequencies with less than 1 Hz resolution
AND accuracy, then there is no reason one could not listen to the beat
between that signal generator and the BFO one is aligning to get +/- 1 Hz
accuracy. It does not matter that the audio stages of a receiver don't
pass sub Hertz audio frequencies, because you can hear sub Hertz
modulation of noise. Any AM receiver that can be tuned to the BFO
frequency can hear the beat between the BFO and the signal generator you
are using as a reference. Getting the amplitudes of the reference signal
generator and the BFO adjusted to be able to hear the beat may be a bit
tricky.
Using that same method to adjust the 10 MHz reference oscillator you can
also get it adjusted to within less than one Hertz of your reference
signal generator.
If you are so unlucky as to have both errors adding (the cumulative error
of your two adjustments) instead of cancelling, the whole system would
still be within only a couple of Hertz of correct.
Sure, that is more effort than just looking at the readout of a frequency
counter, but it is a valid and accurate method of accomplishing the task.
Whatever method you use is completely dependent on the accuracy of your
reference, be it the time base in a frequency counter or the time base in
your synthesized signal generator.
DE N6KB
I've said it before and been criticized but one needs a counter to
resolve the required frequencies to 1Hz or better. Confirming SSB USB &
LSB frequency requires measurement, not listening.
Bob, K4TAX
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