Return-Path: Received: (qmail 10369 invoked from network); 26 Jan 2001 11:04:18 -0000 Received: from unknown (HELO murphys-inbound.servers.plus.net) (212.159.14.225) by 10.226.25.101 with SMTP; 26 Jan 2001 11:04:18 -0000 Received: (qmail 22798 invoked from network); 26 Jan 2001 11:07:49 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 26 Jan 2001 11:07:49 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #1) id 14M6VU-0002ti-00 for rsgb_lf_group-outgoing@blacksheep.org; Fri, 26 Jan 2001 10:53:28 +0000 X-Priority: 3 X-MSMail-Priority: Normal Received: from d06lmsgate-2.uk.ibm.com ([195.212.29.2]) by post.thorcom.com with esmtp (Exim 3.16 #1) id 14M6VQ-0002tb-00 for rsgb_lf_group@blacksheep.org; Fri, 26 Jan 2001 10:53:24 +0000 Received: from d06relay02.portsmouth.uk.ibm.com (d06relay02.portsmouth.uk.ibm.com [9.166.84.148]) by d06lmsgate-2.uk.ibm.com (1.0.0) with ESMTP id KAA108998 for ; Fri, 26 Jan 2001 10:38:05 GMT Received: from usa.net (ss7.bld.socks.ibm.com [9.14.4.72]) by d06relay02.portsmouth.uk.ibm.com (8.8.8m3/NCO v4.95) with ESMTP id KAA197088 for ; Fri, 26 Jan 2001 10:52:01 GMT X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Message-ID: <3A715673.2CDC243F@usa.net> Date: Fri, 26 Jan 2001 11:50:27 +0100 From: "Alberto di Bene" Organization: Undisclosed X-Mailer: Mozilla 4.76 [en] (Win95; U) X-Accept-Language: en MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org Subject: LF: RE: VA3LK seen in ON References: <65AECDF1F89AD411900400508BFC869F0D7567@pdw-mail-1.dera.gov.uk> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Talbot Andrew wrote: > [snip] Just as an example of a visual code, 7 frequency levels, using > two sucessive symbols per character gives potential for 49 different > symbols, enough for letters numbers and a few punctuation. There > would be no need to turn off the Tx for any symbol, as a space could be > coded as a character, thus removing ambiguities with dots and noise > spikes. > [snip] Just out of curiosity : I was thinking, a few weeks ago, to a signalling scheme that makes use of 2-out-of-12 tones, with the two tones being sent not sequentially, but simultaneously. I do realize that this would mean that the PA must be linear. Is this a though requirement for the present crop of PAs around ? How much would this requirement be of obstacle to the adoption of such a scheme (which could also be FEC corrected...). TNX 73 Alberto I2PHD