JT65A

JT65A on the waterfall

Begin one for exotic modes, I have become interested in a mode known as JT65A.

From the wiki entry : -

"JT65, developed and released in late 2003 is intended for extremely weak but slowly-varying signals, such as those found on troposcatter or Earth-Moon-Earth (EME, or "moonbounce") paths. It can decode signals many decibels below the noise floor, and can often allow amateurs to successfully exchange contact information without signals being audible to the human ear. Like the other modes, multiple-frequency shift keying is employed; unlike the other modes, messages are transmitted as atomic units after being compressed and then encoded with a process known as forward error correction (or "FEC"). The FEC adds redundancy to the data, such that all of a message may be successfully recovered even if some bits are not received by the receiver. (The particular code used for JT65 is Reed-Solomon.) Because of this FEC process, messages are either decoded correctly or not decoded at all, with very high probability. After messages are encoded, they are transmitted using MFSK with 65 tones.
Operators have also begun using the JT65 mode for contacts on the HF bands, often using QRP (very low transmit power);while the mode was not originally intended for such use, its popularity has resulted in several new features being added to WSJT in order to facilitate HF operation."

Moon Bounce ey? Must be good! So basically the above means JT65A is a weak signal digital QSO mode with a highly structured QSO.

There are not many JT65A operators on 11 meters but I keep transmitting and talking about it on forums and more people are getting interested. I had my first JT65A RX on 11 meters a few weeks ago with my SSTV friend 310LA from Lativa, unfortuantly I was not around to complete the QSO. However, today I had a partial QSO with 161BD520 - Sergiusz over in Poland, thanks Sergiusz! Unfortuantely it appears there is a limit on the callsign length (6 characters) so not really suited for traditional 11 meter calls signs - i'll keep you posted on this one as the experiment continues.

The program I used for JT65A is JT65-HF which can be download here: http://jt65-hf.sourceforge.net/