[NLRS] what's wsjt?

[kb0pyo]

Another mode that works well and can handle multipath is hellschreiber.
					Mark


Bryan LaPlante wrote:
> 
> I had a question on wsjt, so I'll respond to the list in case anyone else
> hasn't heard of it.
> 
> WSJT (weak signal communications by k1jt) is a digital mode which uses 4
> tones to represent characters.  Unlike psk31, only one tone is sent at a
> time, so you acually could use a class C amplifier without problems.  Also
> that means that overdriving your radio's mike input is not much of an issue,
> again unlike psk31.  However, you do need to use a SSB tranciever.
> 
> WSJT is being used as an alternative to high speed CW for meteor ping
> communications.  The program has averaging functions to help prevent false
> decoding.
> 
> >From the web site:
> The first mode implemented, and the one that has given WSJT its wide
> popularity, is called FSK441. It is designed for high speed meteor scatter
> (HSMS) communication using "pings" reflected from the underdense ionization
> trails of random meteors at approximately 100 km height. Such pings are
> typically a few dB above the noise and last for anywhere from ten to a few
> hundred milliseconds. WSJT makes QSOs possible in the amateur 2-meter and
> other VHF bands, over typical distances of 500 to 1400 miles (800 to 2200
> km), using these brief pings. Such QSOs can be successful with modest
> equipment and without waiting for "band openings."
> 
> As a digital mode, you key in text and like RTTY WSJT sends it.  Unlike
> hscw, the program decodes signals it hears and displays clear text.
> 
> I've read a claim (don't see the reference right now) that WSJT can conplete
> QSOs where SSB won't work.  Certainly this is true about pings, but I think
> this was expessed as a S/N advantage over SSB.
> 
> -Bryan kb0obt
> 
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