Return-Path: Received: (qmail 4289 invoked from network); 22 Jan 2003 17:03:58 -0000 Received: from murphys.services.quay.plus.net (212.159.14.225) by mailstore with SMTP; 22 Jan 2003 17:03:58 -0000 Received: (qmail 15868 invoked from network); 22 Jan 2003 17:03:54 -0000 Received: from post.thorcom.com (193.82.116.70) by murphys.services.quay.plus.net with SMTP; 22 Jan 2003 17:03:54 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.12) id 18bOHS-0000cC-00 for rsgb_lf_group-outgoing@blacksheep.org; Wed, 22 Jan 2003 17:03:14 +0000 X-Priority: 3 X-MSMail-Priority: Normal Received: from [193.212.240.200] (helo=virus-in.online.no) by post.thorcom.com with esmtp (Exim 4.12) id 18bOHR-0000c3-00 for rsgb_lf_group@blacksheep.org; Wed, 22 Jan 2003 17:03:13 +0000 Received: from [134.47.162.90] by virus-in.online.no with ESMTP for rsgb_lf_group@blacksheep.org; Wed, 22 Jan 2003 18:02:42 +0100 Received: from tns-fbu-22-215.corp.telenor.no ([134.47.162.192]) by tns-fbu-22-208.corp.telenor.no with Microsoft SMTPSVC(5.0.2195.4453); Wed, 22 Jan 2003 18:02:41 +0100 Received: from tns-fbu-22-213.corp.telenor.no ([134.47.162.191]) by tns-fbu-22-215.corp.telenor.no with Microsoft SMTPSVC(5.0.2195.4453); Wed, 22 Jan 2003 18:02:41 +0100 Received: from TNS-FBU-2E-003.corp.telenor.no ([134.47.164.201]) by tns-fbu-22-213.corp.telenor.no with Microsoft SMTPSVC(5.0.2195.4453); Wed, 22 Jan 2003 18:02:41 +0100 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 content-class: urn:content-classes:message Date: Wed, 22 Jan 2003 18:02:41 +0100 Message-ID: <2D280BB697C7EE4C979C5C89925418EFB05A4D@TNS-FBU-2E-003.corp.telenor.no> Thread-Topic: w3eee.com -10dB Thread-Index: AcLAzqvEaMIftDJWSV+nRahNrsZZZQBaBkhw From: jan-martin.noding@telenor.com To: rsgb_lf_group@blacksheep.org X-OriginalArrivalTime: 22 Jan 2003 17:02:41.0740 (UTC) FILETIME=[134A78C0:01C2C238] MIME-Version: 1.0 Subject: LF: VFO for VLF receiver? Digital type pre-mixer, any ideas? Content-Type: text/plain; charset=Windows-1252; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, hits=2.1 required=6.0tests=NO_REAL_NAME,SPAM_PHRASE_00_01version=2.43 X-Spam-Level: ** X-SA-Exim-Scanned: Yes Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rsgb_lf_group-outgoing@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false Hi planning to build a VFO for a boatanchor VLF receiver covering 50-140KHz, first IF is 169kHz and it was originally using xtal control. The VFO must cover 220-310kHz. The variation needs to 85kHz, and it seems easier to make a VFO above 1MHz, possibly Clapp oscillator (my favourite since everybody else disregard it!), might also try the Seiler. I thought of using a 2457.6MHz xtal and mix with VFO (ca 2MHz), and divide the output by two or more. Suppose I could use an FF, preferably CD4013 for the mixer. But I can't find any reference to similar constructions, only have a vague memory that it has been mentioned in TT some time in the last 35 years Wonder if somebody else have some experience in this, and will the mixer divide or just mix? 960kHz resonators are also readily available, but they won't pull much. 73 Jan-Martin --- J M Nøding, Datakvalitet, TTS, Kristiansand Telefon 0047-380-52660, 9077-7126 (QTH: 0047-380-87178)