Hello RTTY contesters! I just joined this reflector, so please excuse me while
I find my way around...
After reviewing all the comments I could find regarding PSK63, I made some
quick tests this morning by setting my ICOM-761 to CW mode with a 500 Hz filter
in place. This is the most narrow filter I have, as this rig is 10 years old
and has no DSP IF filters.
Using WINPSK for receiving PSK63 as explained on the PSK63 webpage at
http://www.qsl.net/kh6ty/psk63, I set the AFC range to +/- 50 Hz (under
Settings) and transmitted on a dummy load from my totally separate second
IC-761 system, also using WINPSK on PSK63, set the waterfall cursor to the
center of the 500 Hz-wide waterfall, and looked to see how quickly I was able
to find, hear at a particular familiar pitch, and tune in a PSK63 transmission
to get good print without using a mouse, but only the tuning knob of the
IC-761. The tuning knob of the IC-761 has a fixed rate of 5 KHz per revolution.
It seemed to me like it was as easy as tuning RTTY for good print. If this
holds true for you seasoned contesters, then this might be a solution to the
AGC capture by unwanted strong signals outside the passband of interest. I
think the reason it works is that the AFC takes care of the fine tuning, so
once you are within 50 Hz or so, the AFC quickly does the rest and print is
good over a relatively broad range of manual tuning.
I would like very much for some of you to try tuning PSK63 using whatever
narrow filters you have and let everyone know about your experience. PSK63
activity can be found daily now around 14073 (true RF frequency) on 20 meters.
If you start with a SSB filter, set the transceiver dial to 14072, USB, and
look for signals twice as wide as PSK31 around the center of the wide
waterfall. Once you know there are signals to tune in, switch to a narrow
filter and give it a try. PSK63, because of the baud rate, "warbles" faster
than PSK31, and has more of a "rasping" sound than a warble.
In reviewing the messages for this month regarding PSK63, I also noticed some
comments that PSK63 is actually too fast for contesting! If this is the case,
then the low error rate of PSK63 can be made even lower by using QPSK63.
Perhaps some of you can try this with WinPSK by selecting QPSK (USB) and having
your QSO partner do the same. Turnaround time was the big problem with PSK31
and that is why we pursued PSK63, which not only cuts turnaround time, but
transmits the exchange faster, so maybe we could be concentrating on QPSK63 as
the preferred mode. However, QPSK63 has some additional turnover delay compared
to BPSK63, but I tested it with a mock exchange this morning and both BPSK63
and QPSK63 seemed to take about 6 seconds to start, trasnsmit the exchange, and
return to receive on my IC-761. The additional delay was not noticeable.
73, Skip KH6TY
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