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#1
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![]() 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 |
#2
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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. Well, you could, I suppose. Of course there isn't error correction. The received print could be cut and pasted from the screen into a text editor, then saved as the intended file. If you were lucky, you might ge something. But 31 baud would be tortuously slow! 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. Also Caps use more bits. Fortunately the people that use all caps on psk31 don't seem to be the fastest typers. 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. I must admit, what I outlined above would make an interesting experiment Feel free to hit me over the head for quibbling. Nahh, they are some interesting points. - Mike KB3EIA - |
#3
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Stuart Grey wrote:
Hi! [...] 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? * http://psk31.com/ Don't forget my site, psk31.org I have to say that this thread was quite interesting, and worthy of the newsgroup (in contrast to the name calling and infantile grade-school playground behavior that is so frequently seen here). It reminds me of the old days before the non-operating hams started using the newsgroups. All the best, and 73, Dave KZ1O -- Please put DBB04 somewhere in the subject line (this year) if you reply via email, otherwise I will not get your message. Newsgroups postings don't need it. Thanks! |