Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dk04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 1141A380000AB; Mon, 25 Feb 2013 08:23:20 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1U9y18-0004p3-QF for rs_out_1@blacksheep.org; Mon, 25 Feb 2013 13:22:54 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1U9y18-0004ou-CW for rsgb_lf_group@blacksheep.org; Mon, 25 Feb 2013 13:22:54 +0000 Received: from mout.gmx.net ([212.227.17.20]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1U9y02-0005LG-I2 for rsgb_lf_group@blacksheep.org; Mon, 25 Feb 2013 13:22:53 +0000 Received: from mailout-de.gmx.net ([10.1.76.35]) by mrigmx.server.lan (mrigmx002) with ESMTP (Nemesis) id 0Ls67d-1Uq4xi1gLv-013x0P for =?utf-8?q?;?= Mon, 25 Feb 2013 14:21:13 +0100 Received: (qmail invoked by alias); 25 Feb 2013 13:21:13 -0000 Received: from p5B2609E9.dip0.t-ipconnect.de (EHLO [127.0.0.1]) [91.38.9.233] by mail.gmx.net (mp035) with SMTP; 25 Feb 2013 14:21:13 +0100 X-Authenticated: #136974488 X-Provags-ID: V01U2FsdGVkX1+5Ic98fGC53aE3LJGzOBqhBs0K4X5p1ktyIAnqRt YG7B63wfDs8ki7 Message-ID: <512B6541.5000607@gmx.net> Date: Mon, 25 Feb 2013 14:21:05 +0100 From: Tobias DG3LV User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130215 Thunderbird/17.0.3 MIME-Version: 1.0 To: Graham , rsgb_lf_group@blacksheep.org References: <550D96E6213544BCB4A78605E3024747@AGB> In-Reply-To: <550D96E6213544BCB4A78605E3024747@AGB> X-Y-GMX-Trusted: 0 X-Spam-Score: -0.7 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi Graham ! An alternative would be to use hardware like two cascaded active rectifiers using OP-amps to get the frequency x 4. As those digital modes do not need linear sine waves on transmit, it is no problem using even square-wave-tones for modulation. Maybe some filtering is necessary to not overload the AF-input of the transmitter. [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [212.227.17.20 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (dg3lv[at]gmx.net) -0.0 SPF_PASS SPF: sender matches SPF record -0.7 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain X-Scan-Signature: f38d515a9cad1e977fcfe251941a8120 Subject: Re: LF: DSP app to multiply tone by 4 ? 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-global-disposition: G x-aol-sid: 3039ac1db408512b65c84e72 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Hi Graham ! An alternative would be to use hardware like two cascaded active rectifiers using OP-amps to get the frequency x 4. As those digital modes do not need linear sine waves on transmit, it is no problem using even square-wave-tones for modulation. Maybe some filtering is necessary to not overload the AF-input of the transmitter. This circuit could be realised as an inline-PCB between soundcard output and TRX input. Certainly such a "solution" is not really "elegant", but should do the trick. 73 de dg3lv Tobias Am 25.02.2013 13:24, schrieb Graham: > DSP app to multiply tone by 4 ? > One thing that one of the PA (Dutch PA) stations spotted , is the 477 > band is a handy divide by 4 from 1.9MHz .. and if you use two > flip-flops , you can divide from 1.9 to 477 > > Setting the rtty shift x 4 in fl digi 340 HZ , then gives 85 Hz at 477 > > A problem with the multi tone modes , unless its possible to write a 'dsp' > app , that multiplies the tones by 4 , single tone fixed amplitude in > real-time or slightly after , > That would open up all the (non linear) modes > to 477 , X2 for 'logic' drive amps, X2 drive, and X4 for conventional on > frequency amps ? > Q Is this a possibility ? > Could something be coded , that either looked like a sound card > , or took audio in , and outputted a multiplied frequency by 2 or 4 > Could have delay as long as the delay was fixed ? > G..