Dear Mark & the Group,
Let me share my ideas with you.
1) Use of an acoustically resonant speaker is always a good idea. I
recommend the SkyTek that I have - it's very nice & you could pick up a
used one. Alternatively, place a 2" speaker in a coffee can. No need for
a calibrated side tone, when the other guys signal "peaks-up" in the
speaker you have a zero beat.
3) Acceptable stability for me means the other guy doesn't drift out of
your passband while you're talking with him. If you have a 500Hz filter
and he is in the center, he can drift 250Hz and still be OK. Probably he
won't talk more than 5 minutes, so 12 X 250 = 3KHz/Hour is an acceptable
number. It's actually more desirable to have a little drift because you
don't have to keep up your hand moving the dial to change the beat tone, a
drifty rig automatically does that for you. Always "touch-up" your
frequency just before he turns it to you, adjusting after you're on the air
will freak out the other operator. If you "touch-up" just before you take
it, others will think your rig is "super-stable" and they will never notice
250Hz of drift that is gradual while you're talking. Of course, a rig has
to be TERRIBLE to drift that much! Bottom line, almost any rig is stable
enough to meet your criterum.
To: <tentec@contesting.com>
>Date: Tue, 15 May 2001 23:12:37 -0400
>From: "Mark Erbaugh" <mark@microenh.com>
>Subject: [TenTec] Omni V questions
>
>Omni V fans,
>
>1) what is the recommended / proper way to zero beat a CW signal with the
>Omni V? It doesn't appear to have a spotting tone and you can't use the
>sidetone with transmitting (I think). Short of switching to SSB, I don't
>think there is a way to remove the BFO offset and tune for a zero beat. What
>I've done so far is to monitor the received signal on my computer using the
>DigiPan waterfall and tune for a 600 Hz signal (I'm too tone deaf to do it
>by ear, but I think with practice, I may learn).
>3) What is acceptable frequency stability? After the radio had been on for
>30 minutes (mostly receive). I tuned in to WWV's (10 MHz) carrier until I
>got about a 1kHz tone. I monitored this tone using the waterfall in DigiPan
>with AFC enabled. After 10 minutes, the tone had increased 4.6 Hz, after 30
>minutes, 10.4 Hz, after 45 minutes, 13.2 Hz and after 60 minutes 14.8 Hz.
>
>73,
>Mark
W B Reese
Primary: WB6TMY@arrl.net
Secondary: Radions@neteze.com
Web: http://www.neteze.com/radions
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