Return-Path: Received: from mtain-mc02.r1000.mx.aol.com (mtain-mc02.r1000.mx.aol.com [172.29.96.74]) by air-mc02.mail.aol.com (v129.4) with ESMTP id MAILINMC023-a8d54d35dbaf1cc; Tue, 18 Jan 2011 13:27:59 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mc02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 53E1E3800008B; Tue, 18 Jan 2011 13:27:58 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1PfGGj-0003Oq-M3 for rs_out_1@blacksheep.org; Tue, 18 Jan 2011 18:27:01 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1PfGGj-0003Oh-9T for rsgb_lf_group@blacksheep.org; Tue, 18 Jan 2011 18:27:01 +0000 Received: from relay2.uni-heidelberg.de ([129.206.210.211]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1PfGGi-000597-0P for rsgb_lf_group@blacksheep.org; Tue, 18 Jan 2011 18:27:01 +0000 Received: from ix.urz.uni-heidelberg.de (cyrus-portal.urz.uni-heidelberg.de [129.206.100.176]) by relay2.uni-heidelberg.de (8.13.8/8.13.8) with ESMTP id p0IIQwmj016938 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Tue, 18 Jan 2011 19:26:59 +0100 Received: from extmail.urz.uni-heidelberg.de (extmail.urz.uni-heidelberg.de [129.206.100.140]) by ix.urz.uni-heidelberg.de (8.13.8/8.13.8) with ESMTP id p0IIQwll001021 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Tue, 18 Jan 2011 19:26:58 +0100 Received: from [129.206.197.52] (vpn052b.rzuser.uni-heidelberg.de [129.206.197.52]) by extmail.urz.uni-heidelberg.de (8.13.4/8.13.1) with ESMTP id p0IIQtt9023215 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Tue, 18 Jan 2011 19:26:57 +0100 Message-ID: <4D35DB73.3070403@iup.uni-heidelberg.de> Date: Tue, 18 Jan 2011 19:26:59 +0100 From: =?ISO-8859-15?Q?Stefan_Sch=E4fer?= User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.11) Gecko/20100711 Thunderbird/3.0.6 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,RATWARE_GECKO_BUILD=1.426 Subject: LF: DK7FC LF grabber(s) now GPS locked Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit 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-sid: 3039ac1d604a4d35dbae3b05 X-AOL-IP: 195.171.43.25 X-Mailer: Unknown (No Version) LF, After some time of maintenance, my LF grabbers (http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_LF_Grabber.html and http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_LF_DX_Grabber.html) are now back on. Due to the cold days the institute was heated and this caused strong temperature changes (when opening the door and so on) and a visible drift of the signals in QRSS/DFCW60/120, so i decided to build a PLL for my 125 kHz IF. The current grabber RX is using a BF981, downconverting by 125 kHz and running 7 SpecLab instances. The 125 kHz signal is generated by a 8 MHz xtal and a 74HC4060, down dividing to 250 kHz (for the PLL) and 125 kHz, for the IF. The 250 kHz signal and 10 kHz signal is fed to a CMOS4070 XOR gatter that generates a regulation voltage as a function of the duty cycle. The waveform is smoothed by a RC circuit and fed to a 1N4007 (reverse) as the regulating part of the VCXO. 10 kHz comes from a GPS module that is the reference for all my grabbers. The system is running since some hours and seems to work fine. I will display the IF drift for some days. BTW i found that remote controlling the PCs is causing some overflows in SpecLab (if many instances are running). This causes a sudden drift / unlocking during the operation, can still be seen on my LF DX grabber. Just a hint for the remote controlling LF/VLF grabber runners :-) 73, Stefan/DK7FC PS: Tnx to Markus/DF6NM for many suggestions and advice!