Return-Path: Received: (qmail 61354 invoked from network); 13 Apr 2005 14:03:15 -0000 Received: from unknown (HELO ptb-spamcore01.plus.net) (192.168.71.1) by ptb-mailstore04.plus.net with SMTP; 13 Apr 2005 14:03:15 -0000 Received: from mailnull by ptb-spamcore01.plus.net with spamcore-l-b (Exim 4.32; FreeBSD) id 1DLiUe-000Pvq-Cj for dave@picks.force9.co.uk; Wed, 13 Apr 2005 15:05:24 +0100 Received: from [192.168.101.78] (helo=pih-mxcore12.plus.net) by ptb-spamcore01.plus.net with esmtp (Exim 4.32; FreeBSD) id 1DLiUd-000PvX-Re for dave@picks.force9.co.uk; Wed, 13 Apr 2005 15:05:23 +0100 Received: from post.thorcom.com ([193.82.116.20]) by pih-mxcore12.plus.net with esmtp (PlusNet MXCore v1.0) id 1DLkEe-0000Y8-VP for dave@picks.force9.co.uk; Wed, 13 Apr 2005 16:57:01 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1DLiRq-0006ka-Ey for rs_out_1@blacksheep.org; Wed, 13 Apr 2005 15:02:30 +0100 Received: from [193.82.116.30] (helo=relay.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1DLiRq-0006kR-1R for rsgb_lf_group@blacksheep.org; Wed, 13 Apr 2005 15:02:30 +0100 Received: from imo-d22.mx.aol.com ([205.188.144.208]) by relay.thorcom.net with esmtp (Exim 4.43) id 1DLiRn-0000xA-GJ for rsgb_lf_group@blacksheep.org; Wed, 13 Apr 2005 15:02:30 +0100 Received: from G0MRF@aol.com by imo-d22.mx.aol.com (mail_out_v38.7.) id l.c0.2661ebd7 (4560) for ; Wed, 13 Apr 2005 10:02:18 -0400 (EDT) From: G0MRF@aol.com Message-ID: Date: Wed, 13 Apr 2005 10:02:18 EDT To: rsgb_lf_group@blacksheep.org MIME-Version: 1.0 X-Mailer: 9.0 SE for Windows sub 5003 X-SPF-Result: relay.thorcom.net: domain of aol.com designates 205.188.144.208 as permitted sender X-Spam-Score: 0.2 (/) X-Spam-Report: autolearn=no,HTML_30_40=0.056,HTML_MESSAGE=0.001,NO_REAL_NAME=0.178 Subject: Re: LF: JT65 Content-Type: text/html; charset=windows-1252 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_20_30,HTML_MESSAGE, NO_REAL_NAME autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Spam-Filtered: by PlusNet SpamCORE (v3.00) Content-transfer-encoding: 8bit

In a message dated 13/04/2005 13:22:40 GMT Standard Time, dibene@usa.net writes:

I am by no means an expert of JT65, but, as far as I know, its coding
takes into account
the structure of the call signs of the hams active in EME mode, using
them as an alphabet of
symbols to search into. Probably the excellent ideas behind JT65 could
be used for a new
program, but I doubt that JT65 can be used as it is.... but of course I
may be proved wrong,
as often happened...

Hello Alberto.

I'm no expert either and I quite agree standard JT65 is too wide and the tone 'bursts' probably too fast for optimal use on LF.

However, I recall from the notes that come with the software that there is a mode which does not anticipate the EME sequence. This was introduced after several DX-Peditions found that odd prefixes and suffixes would not be accepted in normal operation. I understand you still have to send a particular number of characters, but it allows random message formats.

My thought was that if this mode was used and characters selected that occurred close to the JT65 sync tone, then the overall transmission may be narrow enough to try on LF.

Just to see if the idea of building up a message over several transmission periods with TX and RX both time synchronised could allow an evaluation of the technique.

Of course the current controversy on the EME reflector revolves around the present version of JT65 using a table of callsigns of active EME stations. Probably best to not add active LF stations to that database.

Regards

David