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 autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: : mailn 1480; Body=3 Fuz1=3 Fuz2=3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u1) with ESMTP id v5QL1huQ009297 for ; Mon, 26 Jun 2017 23:01:44 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1dPb0I-0006TM-V4 for rs_out_1@blacksheep.org; Mon, 26 Jun 2017 21:53:02 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1dPb0I-0006TD-4e for rsgb_lf_group@blacksheep.org; Mon, 26 Jun 2017 21:53:02 +0100 Received: from lethe.lipkowski.org ([178.32.151.135] helo=lipkowski.org) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1dPb0F-0002GX-DT for rsgb_lf_group@blacksheep.org; Mon, 26 Jun 2017 21:53:00 +0100 Received: from mailn.lipkowski.org (localhost [127.0.0.1]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u1) with ESMTP id v5QKrg47009249 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 26 Jun 2017 22:53:42 +0200 Received: from localhost (sq5bpf@localhost) by mailn.lipkowski.org (8.14.4/8.14.4/Submit) with ESMTP id v5QKrf5K009246 for ; Mon, 26 Jun 2017 22:53:42 +0200 X-Authentication-Warning: mailn.lipkowski.org: sq5bpf owned process doing -bs Date: Mon, 26 Jun 2017 22:53:41 +0200 (CEST) From: Jacek Lipkowski To: rsgb_lf_group@blacksheep.org In-Reply-To: <59512E45.6090701@posteo.de> Message-ID: References: <594D2630.3000709@posteo.de> <15cd91cc8cc-d71-1057d@webprd-a66.mail.aol.com> <59512E45.6090701@posteo.de> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.75 X-Scanned-By: MIMEDefang 2.75 on 10.1.3.10 X-Scan-Signature: f38d515a9cad1e977fcfe251941a8120 Subject: Re: LF: Neo6M vs Neo7M Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed 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 Status: O X-Status: X-Keywords: X-UID: 12126 On Mon, 26 Jun 2017, DK7FC wrote: > Is there any improvement of the Neo-7M over the Neo-6M? [...] the neo-6m can generate up to 999Hz on the timepulse output. this is good for a 1pps timing source for vlfrx-tools (just shorten the timepulse to 1ms, it's 100ms by default) the neo-7m can generate up to 24MHz on the timepulse output, but this is a NCO with 48MHz clock, so for clean output pick frequencies which are 48MHz/N where N is integer. this is a good reference for transmit applications (of course it can do 1pps too). the other difference is that while the chiniese boards with both neo-6m and neo-7m often have an eeprom on board, only the the neo-6m will read it upon startup. or at least i haven't been able to make the neo-7m start with my settings after powerup. to solve this i use a simple C program to talk UBX protocol to the gps to set the required parameters. in my case this is 57600 baud, disable SBAS, set 20kHz timepulse on lock, and set 4Hz refresh rate. i use the nmea output to set time via ntpd, and the 20kHz signal as a reference to ebsynth (right now i use it for sending stable carriers, but eventually will do ebnaut too). i can post the program in case anyone is interested. another fun fact: these are really cheap gps-es with not-so-stable clocks. you can break the gps lock by changing the temperature quickly, even by blowing compressed air at it. use a lot of thermal isolation. VY 73 Jacek / SQ5BPF