[NLRS] what's wsjt?

[Bryan LaPlante]

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