And, with that setup, you can also calibrate your radio!
Use AM operation first to calibrate the soundcard. If WWWV is putting out a
600 Hz tone, you should see a 600 Hz trace on the waterfall. If it is not
exactly 600 Hz, then you have a soundcard calibration error. Some PSK31
programs provide for card calibration. In any event, note any error as it
will be essentially constant.
Next, detune WWV 1000Hz and look for the 1000Hz trace. Adjust the frequency
readout on the display for any card error and that is your radio
calibration error. Adjust to compensate until the waterfall shows the 1000
Hz line exactly at 1000 Hz +/- any card error. My card error alternates
between 0 and 0.1 Hz so I tend to ignore it.
My non-TT radio - sorry about that! - starts about 5 Hz off from a cold
start and is within 2 Hz within 5 minutes. It never moves after that . . .
I like the DigiPan program for this sort of thing.
72/73, George W5YR - the Yellow Rose of Texas QRP-L 1373 NETXQRP 6
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe
Amateur Radio W5YR, in the 56th year and it just keeps getting better!
Icom IC-756PRO #02121 Kachina #91900556 IC-765 #02437
Mark Erbaugh wrote:
> One consideration is the frequency stability of the rig. Until my Omni V
> has warmed up for 30 to 60 minutes, the frequency drift is too much for my
> PSK31 operating tastes. PSK is a very narrow signal and while the
> software's AFC will compensate for any frequency drift, if you're not
> careful you'll end up chasing each other all over the band and possibly
> right into someone else's QSO.
> Fortunately, the current software makes it pretty easy to measure Rx
> frequency stability. I just tune to a heterodyne from WWV and click on it
> on the waterfall and note the frequency. Enable AFC on the software and it
> will track the tone.