[amsat-bb] Re: Icom D-Star
Edward R. Cole
kl7uw at acsalaska.net
Sun Apr 24 12:49:15 PDT 2011
At 11:18 AM 4/24/2011, Diane Bruce wrote:
>On Sun, Apr 24, 2011 at 02:36:37PM -0400, Sebastian wrote:
> > Never heard of WSJT?
>Never heard of it.
>- 73 Diane VA3DB
I'm surprised as involved in mw as you are.
Here is a link to the software:
Joe Taylor, K1JT, was a professor (now emeritus) at Princeton and a
Noble Laureate for his work with Pulsars.
He first wrote FSK-441 as a digital mode for meteor scatter which has
essentially replaced high speed CW as the primary mode on ms. Then
he developed a weak-signal program for eme about 2002 (it is nearing
ten years). The group of programs was bundled into a suite called
WSJT (weak-signal JT). The prime mode for 2m eme is now JT-65; CW
has been largely replaced. JT-65 uses noise reduction algorithms
taken from the Reed-Solomon sw that is used for NR on DVD's. JT-65
is a very narrow band digital mode occupying only 4.7 Hz, thus it
demonstrates SNR > 10 dB over CW. It is a synchronous digital mode
so it requires precise timing and frequency. Most users use internet
sw to maintain their computer time <1 sec error.
One offshoot is the propagation beacon sw, WSPR "whisper", which is
very popular on HF for determining band conditions. Many stations
only run 1w or less with the sw.
Maybe you have heard of these programs but not under the name of the
bundled suite (WSJT).
73, Ed - KL7UW, WD2XSH/45
BP40IQ 500 KHz - 10-GHz www.kl7uw.com
EME: 50-1.1kW?, 144-1.4kw, 432-100w, 1296-testing*, 3400-?
DUBUS Magazine USA Rep dubususa at hotmail.com
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