Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dk04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 4A01D380000AF; Thu, 20 Oct 2011 18:26:31 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1RH13R-0004vB-Nj for rs_out_1@blacksheep.org; Thu, 20 Oct 2011 23:25:37 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1RH13R-0004v2-Av for rsgb_lf_group@blacksheep.org; Thu, 20 Oct 2011 23:25:37 +0100 Received: from mail-bw0-f43.google.com ([209.85.214.43]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1RH13P-0007ub-7Q for rsgb_lf_group@blacksheep.org; Thu, 20 Oct 2011 23:25:37 +0100 Received: by bke17 with SMTP id 17so6936824bke.16 for ; Thu, 20 Oct 2011 15:25:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=4trSzwcKp5nn3awrtCz/3gfln0KPKYr39nnY02cIvYE=; b=AL2MvdLzqW0nai3mpe/O2X1Ip7JF+W96oWdpeR6UlHS5CtYqxyto3Gx3xj7u8we/k6 URhZOgM+hoZWlcpB/0Y9D+XS2P62dT+sQ0rBpqRRg8HCXWZb9Ph1mvfL35DHtMSCq1IN 5hsdP0fDkjwQwAMAWXwoHS0yVsugipUtLnSXw= MIME-Version: 1.0 Received: by 10.204.152.195 with SMTP id h3mr9126341bkw.1.1319149527659; Thu, 20 Oct 2011 15:25:27 -0700 (PDT) Received: by 10.204.173.2 with HTTP; Thu, 20 Oct 2011 15:25:27 -0700 (PDT) In-Reply-To: <4E9FF511.4050203@iup.uni-heidelberg.de> References: <4E9F01CB.2050302@iup.uni-heidelberg.de> <4E9FF511.4050203@iup.uni-heidelberg.de> Date: Fri, 21 Oct 2011 09:25:27 +1100 Message-ID: From: Dimitrios Tsifakis To: rsgb_lf_group@blacksheep.org X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: OK2BVG_8970 Content-Type: text/plain; charset=ISO-8859-1 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-SCOLL-SCORE: 0:2:492594016:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-m006.2 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1db4084ea0a0172643 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Hi Stefan, > This is what i use on my grabber: > http://www.iup.uni-heidelberg.de/schaefer_vlf/8,97kHz%20active%20E%20field%20antenna%20by%20DK7FC.jpg That looks simple enough and from what I see, there are other happy customers (4x1RF, G3XBM and TF3HZ) so I'll make one. :-) Don't have the BF862 FETs but may have something similar, maybe J310 or MPF102? Need to look at the datasheets. > Mostly they are locked internally, i.e. by SpecLab. You have to lock on a > reference frequency to correct the soundcard xtal drift. This can be done by > using a small GPS module (running from the 5V of the USB) that has a 10 khz > output. You can see the 10 kHz line in my wideband spectrogram on the bottom > of the grabber site. > Alternatively you can lock on a MSK transmitter (military) if one is > available. In VK, there is NWC on 19.8 kHz which is in OG78BE (locator). You > should have good reception of that transmitter since we can see it here in 1 > Hz as well. Oh yes, the Exmouth station is very very strong here, very strong, audible signal. That makes things simple. The other option is to use a soundcard that has a 10 MHz clock input and connect it to my Rb reference. There are a couple of friends that experiment with these, but to be honest, I like the simplicity of using SL to lock to a known good signal. 73, Dimitris VK1SV