Stuart Grey wrote:
Mike Coslo wrote in
:


Stuart Grey wrote:



Oh yeah! I gotta have a question. Okay, here’s one; I’m
interested in this PSK31 * thing. Does anyone do PPP via
this modulation technique, like to pass primitive usenet
like messages, old ftp, or text based web pages?


No, it is a text based mode. Phase shifting can
certainly be used to
send data, but PSK31 is the shifting and an encoding scheme
that sends text only. Correctable too!

Of course, you can send ascii art!

- Mike KB3EIA -


The primitive usenet was all text - mail, usenet, and text based
web using Lynx, connected via PPP.

BUT, if I can send text, I can uuencode binary files, and send
them as text. This whole web thing is entirely text based, yet
by uuencode and other schemes binary files can be passed, and
applications can be created that make viewing or using those
binary files seem transparent.

BUT, THEN AGAIN, PSK31 uses vericode, which appears, at first
glance to be optimized for English language text messages, with
the vowels being of the shortest number of bits and less
frequently used letters being many more bits. Optimal for
English, much less so for binary. I’ve not looked at it to see
what its efficiency would be compared to other schemes, so I
really shouldn’t say.

BUT, STILL AGAIN, I wouldn’t dream of sending anything but text
via PSK31. I just think it might be cool to use something like
PPP to relay messages about, sort of like repeaters, but not
real time. After all, the original internet was just a few
computers that connected with phone lines at low bit rates; not
at all unlike radio contacts made with PSK31.

Feel free to hit me over the head for quibbling.

PSK31 or any PSK does not have error correction, so the messages
might not arrive in "one piece" and one could spend many hours trying
to send one "good version". PSK was designed to take over where RTTY
left off as far as a keyboard mode for QSO's. Speed is about the same
60 WPM for BSK31, but less bandwidth and a little better under poor band
conditions. MFSK has some error correction but again the speed is about
60 WPM, would take a long time to send complete pictures. MixW has a
feature for sending pictures via MFSK, works well but not anything
like the Internet or even SSTV, picture quality is very poor. Right now
the MFSK picture mode is not lawful in the USA, but there is a petition
before the FCC to allow bandwidth up to 500 Hz for some of the new
digital modes like MFSK picture mode which is a FAX mode in reality
There is PACTOR with error correction, but again the baud rate is 300
bps on HF. Would be like using a early modem connected to the telephone
line. If you were around for the first BBS systems they were very
slow. Took me four evenings at one hour per session to download
the satellite tracking program STSPLUS, and that was not a very
large file compared todays software. I believe the connection
speed to the BBS was 1200 bps then.

Even message sending via Packet and PACTOR is getting to be less
and less with satellite phones and cell phones and email via the
Internet. But your idea is interesting about PPP messages,
but would be much to slow for todays high tech communications.
Would you be willing to sit at your station for many hours to
download a few messages? And then many hours to relay them?

My two cents worth.

JJJHS