Return-Path: Received: from mtain-dj05.r1000.mx.aol.com (mtain-dj05.r1000.mail.aol.com [172.19.187.141]) by air-da09.mail.aol.com (v129.4) with ESMTP id MAILINDA091-85eb4c2529b819; Fri, 25 Jun 2010 18:12:08 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-dj05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 05DCE3800020E; Fri, 25 Jun 2010 18:11:59 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OSH78-0000cL-A0 for rs_out_1@blacksheep.org; Fri, 25 Jun 2010 23:11:10 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OSH77-0000cC-Rp for rsgb_lf_group@blacksheep.org; Fri, 25 Jun 2010 23:11:09 +0100 Received: from mail-fx0-f43.google.com ([209.85.161.43]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OSH75-0004qH-63 for rsgb_lf_group@blacksheep.org; Fri, 25 Jun 2010 23:11:09 +0100 Received: by fxm8 with SMTP id 8so3142144fxm.16 for ; Fri, 25 Jun 2010 15:11:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:content-type; bh=FOxRuQ+gzxHPrl2C67q2AgE+VrrsyG2IMgq1QrHNgsg=; b=Jnp4XVLfw4IYJkd06nPpJpR+vLDHIzLWWgeFklofoBc5ecf0hScPNZ0mAVwHcLoMQV JPnCnrXT/TfR5H5i/XIS1MgB5nkBbVXLXP86HbQCNKT/uxkcQvpz7AdWYkL23p9XRXO/ CNQ/V8Z9WjX5ICdsVInwv/cgOxHN09GCcMP+A= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=TL6nd3E1600AKo66AOc44wcL2ptf8GzVFIcVNgT3nEQyJOcrjp+ZZozETmXgDM70Dj pL2JoNWrfRoyE38cFYEvwLJHf7lNWXRL6SJgoGDirfeXyLsMJkFIus3nbivKf/7KrKvE 0Yt/iusjtOpp7sugjNzCB8ReLuBbDCBmnXh3w= MIME-Version: 1.0 Received: by 10.204.74.10 with SMTP id s10mr949687bkj.26.1277503860526; Fri, 25 Jun 2010 15:11:00 -0700 (PDT) Received: by 10.204.67.18 with HTTP; Fri, 25 Jun 2010 15:11:00 -0700 (PDT) In-Reply-To: References: Date: Fri, 25 Jun 2010 23:11:00 +0100 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: 137kHz transmitters Content-Type: multipart/alternative; boundary=0016e6d97635ce4fbd0489e20b06 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.9 required=5.0 tests=HTML_30_40, HTML_FONTCOLOR_UNSAFE,HTML_MESSAGE 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-AUTHENTICATION: mail_rly_antispam_dkim-m218.1 ; domain : googlemail.com DKIM : pass x-aol-sid: 3039cdbc9d0a4c2529af28c5 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --0016e6d97635ce4fbd0489e20b06 Content-Type: text/plain; charset=ISO-8859-1 A circuit diagram of the divider using a pair of 74xx161 devices can be seen in the top left of www.g4jnt.com/UWLOLCK2.GIF But as others have pointed out, you'll probably need a 50% duty cycle square wave, in which case use a single xx161 with feedback in the same way to divide by 13, then a xx74 device (or whatever) for the final /2 Andy www.g4jnt.com On 25 June 2010 18:36, Andy Talbot wrote: > A pair of old fashioned 74xx161 devices (inverter needed, too) > > Hardwire a preset loaded values of (256 - N), it counts up from that and > reloads the preset value when the count rolls over from 255 to 0 > > Andy > www.g4jnt.com > > > On 25 June 2010 18:29, Roger Lapthorn wrote: > >> 3560 and 3579kHz, both cheap crystals, divided by 26, give CW and QRSS >> frequencies on 136/137kHz. What is the simplest and cheapest way of getting >> divide by 26? >> >> 73s >> Roger G3XBM >> >> -- >> http://g3xbm-qrp.blogspot.com/ >> http://www.g3xbm.co.uk >> http://www.youtube.com/user/g3xbm >> G3XBM GQRP 1678 ISWL G11088 >> > > --0016e6d97635ce4fbd0489e20b06 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
A circuit diagram of the divider using a pair of 74xx161 devices can= be seen in the top left of=A0
=A0
=A0
But as others have pointed out, you'll probably need a 50% duty= cycle square wave, in which case use a single xx161 with feedback in the= same way to divide by 13, then a xx74 device (or whatever) for the final= /2
=A0
On 25 June 2010 18:36, Andy Talbot <andy.g4jnt@googlema= il.com> wrote:
A pair of old fashioned=A0=A074xx161 devices (inverter needed, too)
=A0
Hardwire a preset loaded values of (256 - N), it counts up from that= and reloads the preset value when the count rolls over from 255 to 0
On 25 June 2010 18:29, Roger Lapthorn <= rogerlapthorn@gmail.com> wrote:
3560 and 3579kHz, both cheap= crystals, divided by 26, give CW and QRSS frequencies on 136/137kHz. What= is the simplest and cheapest way of getting divide by 26?

73s
Roger G3XBM

-- http://g3xbm= -qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www= .youtube.com/user/g3xbm
G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G110= 88


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