[RTTY] New contesting PSK faster than RTTY

[Dave Bernstein]

WinWarbler utilizes PSKCORE.DLL as its PSK engine. If there is serious
interest in exploring PSK63, I can quickly release a version that
compensates for the  "freq/2" defect mentioned below. Let me know...

    73,

       Dave, AA6YQ


-----Original Message-----
From: rtty-bounces at contesting.com [mailto:rtty-bounces at contesting.com]
On Behalf Of Richard Ferch
Sent: Sunday, May 04, 2003 9:57 PM
To: rtty at contesting.com
Cc: aa5au at bellsouth.net
Subject: Re: [RTTY] New contesting PSK faster than RTTY


On Sun May 4 20:07:23 EDT 2003, Don Hill AA5AU said:

> I'd be willing to try it, but it's still going to be AFSK.  Where do 
> we get the software?
>
> AFSK - if I wanted to send audio to my radio, I'd go hunt for my 
> microphone...
>
> RTTY Forever,
> Don AA5AU

Hi Don,

It's basically the same as PSK31 except at twice the speed (and
therefore twice the bandwidth). So far, the only code I have seen for it
is in KH6TY's experimental version of the PSKCore.dll file at
http://www.qsl.net/kh6ty/psk63/ - the actual file is at
http://www.qsl.net/kh6ty/psk63/psk63core.zip .

In addition to the dll itself, you need a PSK program that uses the
PSKCore dll. I could be wrong, but I don't think WriteLog is one. Those
that I am aware of includeWinPSK (http://www.qsl.net/ae4jy/winpsk.htm),
WinPSKse
(http://www.winpskse.com/) and Zakanaka
(http://www.qsl.net/kc4elo/oldfiles.htm) plus several others (I can give
more links if anyone is interested). Many of these programs do not have
much in the way of contesting features (one exception being RCKRtty),
but they can be used to test the characteristics of the mode.

KH6TY's recommendation for using the new file is to keep two copies of
your chosen PSK program in separate folders, one with the original PSK31
PSKCore dll and the other with the new PSK63 version of the dll. An
alternative method would be to place two renamed copies of the dll (e.g.
pskcore31.dll and pskcore63.dll) in the same folder with the software,
and create a couple of little batch files to delete the old pskcore.dll
file and make a copy of the required one and name it pskcore.dll, then
start the PSK software.

One small "bug" to watch out for - the original PSKCore dll returns the
audio frequency, but the new experimental one returns the frequency
divided by two (I guess you can figure out from this how the new version
works!). This means that the waterfall in the PSK software is
compressed, and you will have to zoom in one step more than you would in
PSK31.

So far the two QSOs I have had in this mode were somewhere around
14074.3 kHz true frequency - one with KH6TY (in SC) and one with PJ2MI.
My radio dial was set around 14072.9 in USB, and the reported audio
frequency was about 700 Hz (actually 1400). I haven't heard KB2EOQ yet,
but that's not too surprising on 20 meters - we're in each other's skip
zone. Yep, here W5BBR is in a PSK63 QSO with KB2EOQ on 14074.4 - Bill
has a strong signal here, but I can't see any sign of Andy at all.

Yes, it's AFSK, so you have to watch out for overdriving (no ALC
indication, sound card output level not too near the top). OTOH, it's
faster than RTTY (around 100 wpm, more or less - the characters are
variable length, so it's hard to be precise), and it occupies less
bandwidth (nominally 63 Hz). It will be interesting to see whether it
actually works out. I wouldn't expect it to have much impact on existing
PSK31 ragchewing, because most hams cannot type fast enough to justify
the increased bandwidth over PSK31. For contesting and DXing, where you
can rely almost completely on macros, it seems to have more promise.
Certainly the idea of fitting several QSOs into the same bandwidth as a
single RTTY QSO without giving away anything in speed is an interesting
one.

Besides, Don, this way you can actually make use of the USB mode on your
radio without having to find your microphone (gee, I know one of those
things came with my radio, but I'm darned if I know where I put it!). I
suspect this mode will be most interesting to people who can use narrow
filters in USB or LSB mode. If your radio insists on making you use wide
filters in SSB, it might not be quite so attractive.

73,
Rich VE3IAY




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