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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 - |
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