Return-Path: Received: (qmail 5401 invoked from network); 21 Oct 1999 21:06:22 +0100 Received: from unknown (HELO magnet.force9.net) (195.166.128.26) by guiness.force9.net with SMTP; 21 Oct 1999 21:06:22 +0100 Received: (qmail 25271 invoked from network); 21 Oct 1999 20:13:56 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by magnet.plus.net.uk with SMTP; 21 Oct 1999 20:13:56 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 11eO2a-0001iG-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 21 Oct 1999 20:38:24 +0100 X-Priority: 3 X-MSMail-Priority: Normal Received: from as-img-6.compuserve.com ([149.174.217.151] helo=spamgaaf.compuserve.com) by post.thorcom.com with esmtp (Exim 3.02 #1) id 11eO2Z-0001iB-00 for rsgb_lf_group@blacksheep.org; Thu, 21 Oct 1999 20:38:23 +0100 Received: (from mailgate@localhost) by spamgaaf.compuserve.com (8.9.3/8.9.3/SUN-1.7) id PAA05920 for rsgb_lf_group@blacksheep.org; Thu, 21 Oct 1999 15:38:10 -0400 (EDT) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Date: Thu, 21 Oct 1999 15:37:03 -0400 From: "Prof R. Jennison" Subject: LF: DAYTONG converters. To: rsgb_lf_group@blacksheep.org Message-ID: <199910211537_MC2-89EF-4462@compuserve.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Disposition: inline Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: About 2 weeks ago I mentioned an intense and troublesome carrier on about 36 kHz which produced a very strong second harmonic on the ham band at 72 kHz. From the strength of the second harmonic I deduced that it was local but I could not locate it. Since then I have done further tests and found that it is associated with the Datong converter. The receiver used with the converter was an ICOM 735. I then tried it with an ICOM 740 but there was no change. I then tried another Datong converter and the signal dissappeared from 72 kHz but appeared, as large as life, on 65kHz with a fundamental on 32.5 kHz. The only way that I can subdue it is to reduce the d.c. supply to the converter to 3 volts but it is still faintly present. The Datong converter is a bit of a "black box" with an integrated circuit at its heart. I have no deails of this integrated circuit and I am very puzzled by the phenomenon. The 4th harmonic is also quite detectable and with some converters it may well appear arround 136 kHz so it may be useful to us all to find the solution. Can anyone help? 73. Roger. G2AJV.