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HSMS med WSJT. OZ1PIF, Peter Frenning EDR Roskilde Afd. Torsdag den 29. November 2001. Hvad er WSJT?. W eak S ignal by k1 JT
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HSMS med WSJT OZ1PIF, Peter Frenning EDR Roskilde Afd. Torsdag den 29. November 2001
Hvad er WSJT? Weak Signal by k1JT K1JT = Joe Taylor, Professor i Astrofysik ved Princeton Universitetet i USA. Nobelpris i Fysik 1993 for opdagelsen af Pulsarer ved hjælp af Radioteleskopet i Arecaibo.
Hvorfor køre HSMS? På 144MHz: Tropo op til ca 8-900Km ES sjældent under 2000Km AU sjældent over 1200Km MS 600-2000+Km! På 50MHz: Uinteressant, afstande allerede dækket ind af ES På 432Hz: Nye muligheder at udforske!
JUST HOW FAST IS HSCW? IS IT MUCH FASTER THAN SSB? Here are some examples: (lpm = wpm x 5) [lpm, letters per minute; wpm, words per minute]. Typical CW 25 wpm 125 lpm Fast CW 50 wpm 250 lpm (Limit of most "regular speed" MS operation) SSB 250 wpm 1250 lpm Slow HSCW 300 wpm 1500 lpm Kinda slow HSCW 400 wpm 2000 lpm (used for CQ's in North America) Faster HSCW 800 wpm 4000 lpm (common schedule speed in North America) Still faster HSCW 1200 wpm 6000 lpm (used for many skeds now) Very fast HSCW 1600 wpm 8000 lpm Ultra fast HSCW 3200 wpm 16,000 lpm (not recommended, S/N Ratio bad. But has been done!) You can see that even slow HSCW is as fast as most SSB operators can talk, except maybe for those whose occupation is auctioneering! And receiver tuning and signal strength requirements are not as tight.
SO JUST HOW SHORT CAN THESE PINGS BE AND STILL GET USABLE INFORMATION ACROSS? Very short! In fact, for HSCW, pings or bursts longer than two or three seconds are exciting but are almost a nuisance! We'll leave it up to you do the actual math. But a 1/10th second ping can propagate a complete set of calls at the medium or higher speeds! This might produce a full syllable on SSB! YOU CAN'T COPY THAT BY EAR! AND THE CW DECODERS I'VE SEEN COULDN'T HANDLE ANYTHING LIKE THIS. HOW DO YOU DO IT? Right. The idea is simple. Use a device to slow the code down to something readable. Then copy by ear what has come through.
FSK441 • Frequency shift keying @ 441BAUD • 4 Toner: • 882, 1323, 1764 og 2205 Hz • Hvert tegn kræver 3 toneintervaller, dvs. 3/441sek. (Ca 2.3ms) for afsendelse • Max 48 forskellige tegn, 43 i brug, samme som i PUA-43 alfabetet.
Indkodning The present encoding of each character is defined in the table below. The four tones are labeled 0-3 for the tones 882 through 2205 Hz, in increasing order. The four possible "single-tone" encodings, namely 000, 111, 222, and 333, are reserved in WSJT for special use as shorthand messages. (These characters sent repeatedly amount to pure single-frequency carriers, and their pings are easily recognized by the software and by the human ear.) The present definition of the shorthand messages is respectively "R26", "R27", "RRR", and "73". These messages are very widely used in North American HSMS communications.
32 200 P 33 201 Q 34 202 R 35 203 S 36 210 T 37 211 U 38 212 V 39 213 W 40 220 X 41 221 Y 42 222 [reserved] 43 223 0 44 230 E 45 231 Z 46 232 47 233 ... 63 333 [reserved] 14 032 # 15 033 <Space> 16 100 $ 17 101 A 18 102 B 19 103 C 20 110 D 21 111 [reserved] 22 112 F 23 113 G 24 120 H 25 121 I 26 122 J 27 123 K 28 130 L 29 131 M 30 132 N 31 133 O Character Tones Number sent Character -------------------------- 0 000 [reserved] 1 001 1 2 002 2 3 003 3 4 010 4 5 011 5 6 012 6 7 013 7 8 020 8 9 021 9 10 022 . 11 023 , 12 030 ? 13 031 /
En random QSO 222000 26.5 60 10 16 109 IK1MTZ CQ4 5 10 0 3 0 222100 3.4 60 8 16 109 CY IK1MTZ 0 8 5 0 0 222100 13.1 80 12 17 109 TZ CQ IK1MTZ 4 9 0 8 0 222200 6.8 180 8 26 109 K1MTZ R26 R26 OZ1PIF IK1MTZ 4 5 2 1 0 222200 10.7 100 12 17 109 26 OZ1PIF IK1MTS 8 9 4 7 0 222200 12.4 80 8 16 109 26 OZ1PIF?IK 0 0 7 1 0 222200 26.2 80 9 16 109 1PIF IK1MTU R 4 11 4 5 0 222200 26.8 40 5 16 109 OZ1PIG6 8 9 3 6 0 222300 1.2 280 11 27 109 6 R26 OZ1PIF IK1MTZ R263R26 OZ1PIF II1/E 7 3 2 4 0 222300 11.3 60 9 16 109 Z1PIF IK1M 10 13 7 2 0 222300 18.8 180 16 27 109 OZ PIF IK1MTZ R26 R26 OZ1XIF 1 9 5 5 0 222300 23.8 80 15 17 109 F IK1MTZ R26# 4 10 6 3 0 222400 2.5 360 13 27 109 IK1MTZ R26 R26 OZ1PIF IK1MTZ R26 R26 OZ1 7 9 4 4 0 222400 3.1 60 6 16 109 IF IK1MTZ 3 11 8 2 0 222400 6.4 300 14 27 109 Z1PIF IK1MTZ R26 R26 OZ1PIF IK1 TZ R26 6 9 4 4 0 222400 10.6 40 6 16 109 OZ1PIF 7 7 0 8 0 222400 13.5 120 7 26 109 Z R26 R26 OZ1PIF IH 7 0 5 2 0 222400 17.5 160 6 26 109 IF IK1MTZ R26 R26 OZ1XIF 1 7 1 0 0 222500 6.5 140 11 27 109 IK1MTQ RRR JN35UB GZ/ 5 8 2 3 0 222705 11.2 80 12 17 109 IK1MTZ 7 OZ 5 6 0 4 0 222705 13.7 40 5 16 152 GQ 3XOF 0 2 0 2 0 222705 19.0 200 10 26 109 Z1PIF IK1MTZ 73 OZ1PIF HK1MTZ 7 6 9 2 5 0
Krævede signal niveauer The first column gives the necessary signal level in dB, relative to the noise power in a 2500 Hz passband, forcommunication or signal detection by each mode. The entriesare ordered by increasing sensitivity of the mode: the fartherdown this list, the better the mode is, in terms ofsignal-to-noise ratio. (Actual communication throughput ratesvary rather widely, of course.)
Krævede signal niveauer SignalLevel (dB) Mode Other details---------------------------------------------------------------- +8.1 HSCW Single dit at 10k LPM +7.0 HSCW Single dit at 6k LPM +6.0 SSB Voice, very weak but readable +5.2 HSCW Single dah at 10k LPM +4.1 HSCW Single dah at 6k LPM +1.5 FSK441 Multi-tone WSJT message 0.0 FSK441 Multi-tone WSJT folded message, 160 ms ping, 12 characters -1.5 HSMS Underdense ping, 20 ms, detected in full BW -3.1 WSJT Single-tone message, 20 ms ping, v0.92 decoder -5.0 HSMS Underdense ping, 100 ms, detected in full BW -5.9 CW 20 WPM, single dit, Rx bandwidth 500 Hz -6.6 WSJT Single-tone message, 20 ms ping, v1.0 decoder-10.4 CW 20 WPM, single dit, Rx bandwidth 50 Hz-14.3 FSK441 Multi-tone WSJT 12 character message, whole 30 s file averaged (not implemented in present decoder)-14.6 WSJT Single-tone message, 100 ms ping (not implemented)-29.2 PUA-43 One minute transmission, 28-char msg-30.9 EME-2 One minute of alternating TX/RX intervals, detection only-38.1 PUA-43 One hour, alternating TX/RX, 14 character message decoded-39.8 EME-2 One hour of alternating TX/RX intervals, detection only
Internet Ressourcer • http://pulsar.princeton.edu/~joe/K1JT WSJT Home page • http://www.vhfdx.de/wsjt EU spejl • http://www.qsl.net/w8wn/hscw/wsjt/wsjtfaq.html Shelby Ennis FAQ • http://www.qsl.net/w8wn/hscw/hscw.html Shelby’s generelle MS sider