Return-Path: X-Spam-DCC: paranoid 1233; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, RATWARE_GECKO_BUILD autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id u0PMC4HV016544 for ; Mon, 25 Jan 2016 23:12:04 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1aNpJK-0006fO-Ic for rs_out_1@blacksheep.org; Mon, 25 Jan 2016 22:08:34 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1aNpJJ-0006fB-VN for rsgb_lf_group@blacksheep.org; Mon, 25 Jan 2016 22:08:33 +0000 Received: from mout1.freenet.de ([195.4.92.91]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.86) (envelope-from ) id 1aNpII-0007f4-Mr for rsgb_lf_group@blacksheep.org; Mon, 25 Jan 2016 22:08:32 +0000 Received: from [195.4.92.142] (helo=mjail2.freenet.de) by mout1.freenet.de with esmtpa (ID dl4yhf@freenet.de) (port 25) (Exim 4.85 #1) id 1aNpHz-0006BB-Im; Mon, 25 Jan 2016 23:07:11 +0100 Received: from localhost ([::1]:47528 helo=mjail2.freenet.de) by mjail2.freenet.de with esmtpa (ID dl4yhf@freenet.de) (Exim 4.85 #1) id 1aNpHz-0006ZO-Ev; Mon, 25 Jan 2016 23:07:11 +0100 Received: from mx8.freenet.de ([195.4.92.18]:35973) by mjail2.freenet.de with esmtpa (ID dl4yhf@freenet.de) (Exim 4.85 #1) id 1aNpER-0008WB-I5; Mon, 25 Jan 2016 23:03:31 +0100 Received: from x4d08ff92.dyn.telefonica.de ([77.8.255.146]:51326 helo=[192.168.178.27]) by mx8.freenet.de with esmtpsa (ID dl4yhf@freenet.de) (TLSv1.2:DHE-RSA-AES128-SHA:128) (port 587) (Exim 4.85 #1) id 1aNpER-0005lK-DO; Mon, 25 Jan 2016 23:03:31 +0100 To: rsgb_lf_group@blacksheep.org, RSGB From: =?UTF-8?Q?Wolfgang_B=c3=bcscher?= Message-ID: <56A69BB1.7010105@freenet.de> Date: Mon, 25 Jan 2016 23:03:29 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 X-Originated-At: 77.8.255.146!51326 X-Scan-Signature: e09cca6d8e44a91eadbdfb3e1b8aec09 Subject: LF: GPSDO experiments Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: RO X-Status: X-Keywords: X-UID: 6522 Greetings all, My GPSDO prototype (with not just a frequency-locking, but also phase-locking loop) seems to run reliably now. But there is one thing which puzzles me, maybe someone here has more experience with 'commercial' VCOCXOs. Mine was found at a hamfest, labelled "OFC MC598X4 - 010W 10.000000 MHz" The tuning range, compared against GPS, is as follows: Vctrl = 0 V -> output frequency 10 MHz - 57 Hz Vctrl = 5 V -> output frequency 10 MHz Vctrl = 12 V -> output frequency 10 MHz + 80 Hz So the 'electric' tuning range is - 5.7 ppm to + 8 ppm. Isn't this a bit much for an oscillator labelled "10.000000 MHz" ? I had expected a tuning range of a few Hz (since the frequency is specified with 1 Hz resolution on the label). If anyone is interested in the PIC "C" sourcecode (written for a PIC16F1783), I can post it on a website as soon as some cosmetic issues (and curses about the PIC datasheet) have been fixed / removed. All the best, Wolf DL4YHF .