On Fri, 8 Jun 2007 23:06:31 +0100 "Julian G4ILO" <[EMAIL PROTECTED]> wrote:
> Sorry for an off-topic posting, but I've been hearing a strange data > mode lately, like someone playing a slow tune on about 4 notes. It > sounds like a slow version of Olivia, but none of the settings in my > MixW can decode it, and it's starting to bug me! There's an MP3 of it > at http://www.g4ilo.com/files/datamode.mp3 if anyone would like to try > to identify it. Thanks in advance. > > 73, It's JT65A, as Leigh mentioned. It started to be used more and more on HF about 2 months ago, the explosion in activity follwed similar "what's this mode" postings to the digitalradio Yahoo Group. There's even an internet sked arranging page http://www.chris.org/cgi-bin/jt65talk for terrestrial JT65A. The "normal" use of the mode is for EME. You need WSJT software to use it. Andrew K3UK wrote a "bozo's guide" to using JT65 on HF:- http://www.obriensweb.com/bozoguidejt65a.htm I've actually used it myself, and worked K1JT, Joe Taylor, the author of the WSJT package, on 20m. I've also worked 9V1QQ, Bob, in Singapore. It's an interesting mode to tinker with but I soon slipped back to CW and my K2 when the novelty wore off! Using JT65 involves fixed TX/RX time slots (e.g TX on odd minute/RX on even minute) and very little data is passed. The actual "exchange" takes the form of 2 alternating tones of particular frequency which "hard code" the signal report of "OOO", the acknowledgement of a received report "RO" and the end of the QSO "73". If you listen to a full QSO it will take 5 minutes as each part of the QSO is done sequentially, in 1 minute timeslots. There are other modulation modes in the WSJT package for Meteor Scatter and other esoteric V/UHF propagation modes. HTH! Cheers, John _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
