Return-Path: Received: (qmail 20441 invoked from network); 8 Feb 2001 09:50:50 -0000 Received: from unknown (HELO warrior-inbound.servers.plus.net) (212.159.14.227) by 10.226.25.101 with SMTP; 8 Feb 2001 09:50:50 -0000 Received: (qmail 8515 invoked from network); 8 Feb 2001 09:54:33 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior with SMTP; 8 Feb 2001 09:54:33 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #1) id 14Qnh6-0003QA-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 08 Feb 2001 09:48:52 +0000 X-Priority: 3 Received: from d06lmsgate-2.uk.ibm.com ([195.212.29.2]) by post.thorcom.com with esmtp (Exim 3.16 #1) id 14Qnh5-0003Q5-00 for rsgb_lf_group@blacksheep.org; Thu, 08 Feb 2001 09:48:51 +0000 X-MSMail-Priority: Normal Received: from d06relay01.portsmouth.uk.ibm.com (d06relay01.portsmouth.uk.ibm.com [9.166.84.147]) by d06lmsgate-2.uk.ibm.com (1.0.0) with ESMTP id JAA106352 for ; Thu, 8 Feb 2001 09:33:34 GMT Received: from usa.net (ss7.bld.socks.ibm.com [9.14.4.72]) by d06relay01.portsmouth.uk.ibm.com (8.8.8m3/NCO v4.95) with ESMTP id JAA209910 for ; Thu, 8 Feb 2001 09:46:43 GMT X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Message-ID: <3A826AF0.307EC000@usa.net> Date: Thu, 08 Feb 2001 10:46:24 +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: CW-Keying via Soundcard or PC speaker References: <9c.b79b2c8.27b31b6f@aol.com> 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: > [snip] > So, if possible, stay above 2kHz, then you don't even need a sine wave. > [snip] Well, if you use a perfect square wave, this requirement can be relaxed a bit, as a perfect square wave has only odd harmonic components, so you just need to stay above 1/3 of the audio passband of your TX. The 2 kHz limit can probably be lowered to 1.3 - 1.5 kHz 73 Alberto I2PHD