Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_MED,SPF_PASS,T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: INFN-TO: mailn 1233; Body=2 Fuz1=2 Fuz2=2 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id v6AKb6k0008469 for ; Mon, 10 Jul 2017 22:37:07 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1dUfFa-000189-QL for rs_out_1@blacksheep.org; Mon, 10 Jul 2017 21:25:46 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1dUfFa-000180-1Z for rsgb_lf_group@blacksheep.org; Mon, 10 Jul 2017 21:25:46 +0100 Received: from porthos.netcom.co.uk ([217.72.171.73]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1dUfFW-0005Nu-Dl for rsgb_lf_group@blacksheep.org; Mon, 10 Jul 2017 21:25:44 +0100 X-DKIM-Result: Domain=abelian.org Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=abelian.org ; s=default; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:To:References:Reply-To:Subject:Sender:Cc: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=JZvotRuoJpALqx8dV3/+o8NUx4AJdgt8i/Op6jsT2ks=; b=B7hHaTWcqoeuDZw5bEd74XWOHw FC1j4vhwHeIO8QvePIdvHWsY2fs70yNzvd1o4R5HgcKyUI6XaBRPY3MeJCLU4uOtivgynhNSKgSmW O0yGFdZZqEOMkebP3fUvrl6v9REnYu9SKe0tyOloNJKINrKN+10rUgZtecWPqqMqqFqA=; Received: from i-194-106-52-83.freedom2surf.net ([194.106.52.83]:48029 helo=pn.abelian.org) by porthos.netcom.co.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1dUfFU-0001SX-Ib for rsgb_lf_group@blacksheep.org; Mon, 10 Jul 2017 21:25:40 +0100 Received: from [127.0.0.1] (localhost [127.0.0.1]) by pn.abelian.org (Postfix) with ESMTP id E58224001B4 for ; Mon, 10 Jul 2017 20:25:39 +0000 (UTC) References: <594D2630.3000709@posteo.de> <15cd91cc8cc-d71-1057d@webprd-a66.mail.aol.com> <59512E45.6090701@posteo.de> <4dcecb3a-be19-ff99-866e-10c16762cacf@abelian.org> To: rsgb_lf_group@blacksheep.org From: Paul Nicholson Message-ID: <1b13ce6b-d15a-973f-d6a5-3ef120314fd9@abelian.org> Date: Mon, 10 Jul 2017 20:25:39 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <4dcecb3a-be19-ff99-866e-10c16762cacf@abelian.org> X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - porthos.netcom.co.uk X-AntiAbuse: Original Domain - blacksheep.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - abelian.org X-Get-Message-Sender-Via: porthos.netcom.co.uk: authenticated_id: catchall@abelian.org X-Authenticated-Sender: porthos.netcom.co.uk: catchall@abelian.org X-Scan-Signature: 5c335215f1b3de26d890ee84d49616ce Subject: Re: LF: Neo6M vs Neo7M 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 2.75 Status: RO X-Status: X-Keywords: X-UID: 12210 I bought a cheap NEO-7N based GPS module, https://www.amazon.co.uk/gp/product/B06XXGJPVM/ It just plugs in and works, and it accepts all the regular UBX commands to set timing pulse width, or set a timing frequency. I've got it in frequency mode hooked up to a phase measuring thing, with the reference coming from a Trimble GPSDOCXO. It's only been running 20 minutes and the Trimble is still warming up, but here's a first plot http://abelian.org/vlf/tmp/170710a.gif After it has settled down, we can get an idea how good it would be for a LF LO, by scaling up the phase by the frequency ratio LO/9765.625. The GPS modules is powered through its micro USB socket from an RPi, which also fires the UBX config commands from it using gpsctl > /dev/ttyACM0. I've got the phase measuring thing running on the RPi too - using the Octo audio card. Sample rate jitter on the Octo is cancelled out in this test, as the phase thing just looks at phase difference between two input signals. -- Paul Nicholson --