Stuart,
It's not the acuracy here by displaying to a 1 hertz value that's real
important. It's the ability to adjust the frequency in 1 hertz increments.
I have a mode I call SAM for sync AM that is not really sync AM. What it is
a LSB with a very wide filter centered on the carrier. You can listen to an
AM station and zero beat the BFO to the carrier. This requires the BFO to
be precisely zero beat with the AM carrier in order to be effective. So, in
this case, the ability to adjust the BFO in 1 hertz increments is important.
I don't care if the display is really off 20 hertz, but it is nice to be
able to do a precision zero beat for this mode.
Carl Moreschi N4PY
Franklinton, NC
----- Original Message -----
From: "Stuart Rohre" <rohre@arlut.utexas.edu>
To: <tentec@contesting.com>
Sent: Tuesday, March 04, 2003 11:58 PM
Subject: [TenTec] Precision in Frequency displays
> Let's get real: 1,000,000 Hz (a MHz).
> 1 per cent is 0.01 of that, or 10kHz
> 0.1 per cent is 0.001 of that or 1,000 Hz
> 0.01 per cent is 0.0001 of 1 MHz or 100 Hz
> And 0.001 per cent is the debated 10 Hz!
>
> Now most of the components in ANY radio are not held to tolerances of
0.001
> per cent! Young ears might resolve a 10 Hz difference in tone, but
average
> ears probably cannot zero beat to even that difference. Give the
frequency
> display designers a break, what do you need less than 10 Hz for? IF you
> are off a net by that much, someone will comment on your tone, and you
will
> talk yourself on.
>
> For those who need the most stable frequency source; an optional TCXO is
> available for the Argo V.
> 73, Stuart K5KVH
>
>
> _______________________________________________
> TenTec mailing list
> TenTec@contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
|