Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dd04.r1000.mx.aol.com (Internet Inbound) with ESMTP id C40FB380000B3; Fri, 25 May 2012 14:58:32 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1SXzhB-0006pl-1v for rs_out_1@blacksheep.org; Fri, 25 May 2012 19:57:05 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1SXzhA-0006pc-H2 for rsgb_lf_group@blacksheep.org; Fri, 25 May 2012 19:57:04 +0100 Received: from filter02.i-online.fr ([195.200.78.9]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1SXzgz-0007OR-TZ for rsgb_lf_group@blacksheep.org; Fri, 25 May 2012 19:57:03 +0100 Received: from smtp.qtxt.dns-iol.com ([195.200.78.13]) by filter02.i-online.fr (IceWarp 10.2.2) with ESMTP (SSL) id JXD64740 for ; Fri, 25 May 2012 20:56:40 +0200 Received: (qmail 10084 invoked by uid 507); 25 May 2012 20:56:45 +0200 Received: from unknown (HELO ?192.168.1.102?) (john.rabson@numeo.fr@217.67.155.178) by smtp.qtxt.dns-iol.com with SMTP; 25 May 2012 20:56:45 +0200 From: John Rabson Date: Fri, 25 May 2012 20:56:50 +0200 Message-Id: <495778BC-4950-48D3-B5E4-4DBCE69D729C@numeo.fr> To: rsgb_lf_group@blacksheep.org Mime-Version: 1.0 (Apple Message framework v1278) X-Mailer: Apple Mail (2.1278) X-Spam-Score: -0.0 (/) 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: LF, This is now working! I used the QRP 2000 synthesiser (completed with assistance from G8DQX) and have added a divide-by-100 unit based on the design by G3KAU with some modifications: - the original design assumed 10 to 50 W sine wave input. I left out the attenuator because the synthesiser delivers 2.6 V peak to peak square wave, which is enough to drive the 4017, [...] Content analysis details: (-0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record X-Scan-Signature: 4e3b1488273adbbe9757d6bdd5adf219 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Subject: LF: 137 kHz exciter 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-SCOLL-SCORE: 0:2:436763360:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d40904fbfd658230d X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none LF, This is now working! I used the QRP 2000 synthesiser (completed with = assistance from G8DQX) and have added a divide-by-100 unit based on the = design by G3KAU with some modifications: - the original design assumed 10 to 50 W sine wave input. I left out the = attenuator because the synthesiser delivers 2.6 V peak to peak square = wave, which is enough to drive the 4017, - I was not intending to use anything other than 137 kHz and the power = amplifier requires square wave drive, so I left out the post-divider = filters, - the output from the second divide-by-10 stage is sufficient to drive = my Class E Power Amplifier so I didn't bother with a buffer, - there are several versions of the 4017 but with different capabilities = and voltage ratings. I used the CD74HC4017, - and provided a 6 V rail rather than 13. The unit is now in a die-cast box and I shall shortly be testing it with = the PA into a dummy load. After that, I need to look at software for driving the synthesiser. For = test purposes I have been using the SI570 programmes referred to in the = documentation but they clearly are not appropriate for transmission. Many thanks for all your help and encouragement. 73 John F5VLF=