Return-Path: Received: (qmail 7315 invoked from network); 7 Mar 2001 19:56:11 -0000 Received: from unknown (HELO murphys-inbound.servers.plus.net) (212.159.14.225) by extortion.plus.net with SMTP; 7 Mar 2001 19:56:11 -0000 Received: (qmail 9093 invoked from network); 7 Mar 2001 19:56:15 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 7 Mar 2001 19:56:15 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #2) id 14ajuv-0005Aa-00 for rsgb_lf_group-outgoing@blacksheep.org; Wed, 07 Mar 2001 19:48:13 +0000 Received: from mta2-rme.xtra.co.nz ([203.96.92.3]) by post.thorcom.com with esmtp (Exim 3.16 #2) id 14ajuu-0005AS-00 for rsgb_lf_group@blacksheep.org; Wed, 07 Mar 2001 19:48:12 +0000 Received: from xtr743187 ([202.27.178.135]) by mta2-rme.xtra.co.nz with SMTP id <20010307194722.VBKD15770362.mta2-rme.xtra.co.nz@xtr743187> for ; Thu, 8 Mar 2001 08:47:22 +1300 Message-ID: <00a201c0a740$63a3d240$42b21bca@xtr743187> From: "Vernall" To: rsgb_lf_group@blacksheep.org References: <14313.200103061746@gemini> <01d501c0a69b$569c4f00$5bb51bca@xtr743187> <3AA601E8.5D3A6939@usa.net> Subject: LF: Re: RE: Transcontinental modes - what next? Date: Thu, 8 Mar 2001 08:32:29 +1300 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2919.6600 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Alberto > Hi all, > which would you all prefer as a way to frequency-shift your TX ? > With frequency shift I mean many steps, separated by a fraction of an Hertz. > The first two possibilities that come to my mind are an audio output from the > sound card (requiring then a mixer to bring the tone to the wanted freq.), > or a binary value output from, say, the parallel port, which then would require > a small external board with a DDS or a microcontroller to drive the TX. > > No linearity requirements will be needed. I need your input to not start in a > false direction. TNX for any advices. My preference is to transceive via a PC sound card, and use the likes of an SSB transceiver, i.e. very little different to practices for HF digital modes, except much longer message times. When fine tuning is available on a sound card, it is a very convenient way to arrange for quite accurate LF carriers. 73, Bob ZL2CA