Return-Path: <owner-rsgb_lf_group@blacksheep.org>
Received: from rly-md10.mx.aol.com (rly-md10.mail.aol.com [172.20.29.148]) by air-md04.mail.aol.com (v121_r2.11) with ESMTP id MAILINMD043-92948ab18dd93; Tue, 19 Aug 2008 15:03:06 -0400
Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-md10.mx.aol.com (v121_r2.11) with ESMTP id MAILRELAYINMD101-92948ab18dd93; Tue, 19 Aug 2008 15:02:56 -0400
Received: from majordom by post.thorcom.com with local (Exim 4.14)
	id 1KVWTA-0008NN-0U
	for rs_out_1@blacksheep.org; Tue, 19 Aug 2008 20:02:16 +0100
Received: from [83.244.159.144] (helo=relay3.thorcom.net)
	by post.thorcom.com with esmtp (Exim 4.14)
	id 1KVWT9-0008NE-5Q
	for rsgb_lf_group@blacksheep.org; Tue, 19 Aug 2008 20:02:15 +0100
Received: from smtpout05-04.prod.mesa1.secureserver.net ([64.202.165.221] helo=smtpout05.prod.mesa1.secureserver.net)
	by relay3.thorcom.net with smtp (Exim 4.63)
	(envelope-from <w1tag@w1tag.com>)
	id 1KVWT5-0000lN-B8
	for rsgb_lf_group@blacksheep.org; Tue, 19 Aug 2008 20:02:15 +0100
Received: (qmail 6849 invoked from network); 19 Aug 2008 19:01:29 -0000
Received: from unknown (64.206.3.50)
  by smtpout05-04.prod.mesa1.secureserver.net (64.202.165.221) with ESMTP; 19 Aug 2008 19:01:29 -0000
Message-ID: <48AB191F.2070100@w1tag.com>
Date: Tue, 19 Aug 2008 15:03:59 -0400
From: John Andrews <w1tag@w1tag.com>
User-Agent: Thunderbird 2.0.0.16 (Windows/20080708)
MIME-Version: 1.0
To: rsgb_lf_group@blacksheep.org
References: <281222.921.qm@web26004.mail.ukl.yahoo.com> <001301c901e6$917c2d30$2201a8c0@PC2> <731EB49F88B309428FFDDD2423F810E441C128@HERMES4.ds.leeds.ac.uk> <48AADCE5.7070602@virgin.net> <034D836CD37D497C80547813F78DE240@AGB>
In-Reply-To: <034D836CD37D497C80547813F78DE240@AGB>
X-Spam-Score: 0.0 (/)
X-Spam-Report: autolearn=disabled,none
Subject: Re: LF: Keyboard Modes for 600 Meters
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com
X-Spam-Level: 
X-Spam-Status: No, hits=0.0 required=5.0 tests=none 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-AOL-IP: 193.82.116.20
X-AOL-SCOLL-AUTHENTICATION: listenair ; SPF_helo : n
X-AOL-SCOLL-AUTHENTICATION: listenair ; SPF_822_from : n
X-Mailer: Unknown (No Version)


Dear ++ (Graham), <g>

I think that Olivia uses sequential FSK, not simultaneous tones. I don't 
believe that Jay and I evaluated any simultaneous systems. We did use 
linear PA's during the tests, but that was more for convenience in 
switching back and forth between PSK and FSK systems. The claim is 
generally made that the various FSK modes do not require amplitude 
linearity. It would make an interesting experiment to compare bandwidths 
and perhaps audible keying artifacts between linear and switching amps 
while driving the fairly high Q antennas we use at LF and MF. I'm always 
amazed at how click-free the hard-keyed CW signals are down here.

John A.

Graham wrote:
> Interesting list of modes and tests ,