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: EATSERVER: mailn 1166; 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+deb8u1) with ESMTP id v5HAUe0I026989 for ; Sat, 17 Jun 2017 12:30:42 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1dMAvU-00038p-OX for rs_out_1@blacksheep.org; Sat, 17 Jun 2017 11:25:56 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1dMAvT-00038g-0g for rsgb_lf_group@blacksheep.org; Sat, 17 Jun 2017 11:25:55 +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 1dMAvP-0000FC-Pu for rsgb_lf_group@blacksheep.org; Sat, 17 Jun 2017 11:25:53 +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:References:To:Subject:Sender:Reply-To: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=8KR2vnq/pSBFmdjYHUBezdWuSe2fHsQ1Lo/9PkAwGgg=; b=oibNfb3pL6aCNKn8ayAdQtRd9c cjCt0jssqP35DO/2uADuj1xYsTn11zrsYszYKafVT6m/UItPJZH9sBPKg4dLTawVuNY5szbbL4PMv 6j3js7qPjrWitTc1lgEA4Yw/vLobHsdZJPWwlwBgDbem20uGFFHc43fMnEMjdig1Qmjc=; Received: from i-194-106-52-83.freedom2surf.net ([194.106.52.83]:43717 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 1dMAvO-0002oR-IG for rsgb_lf_group@blacksheep.org; Sat, 17 Jun 2017 11:25:50 +0100 Received: from [127.0.0.1] (localhost [127.0.0.1]) by pn.abelian.org (Postfix) with ESMTP id E6F47400A15 for ; Sat, 17 Jun 2017 10:25:49 +0000 (UTC) To: rsgb_lf_group@blacksheep.org References: <15ca21dc75e-1e15-bcda@webprd-m105.mail.aol.com> <0f9558b4-457d-a395-58c9-7f9be3393cdd@sky.com> <4767d79f-2bf6-d838-bfd4-3e78102d6f5d@abelian.org> <510c15eb-b57a-0ebb-9037-1f83e0652cf2@sky.com> From: Paul Nicholson Message-ID: <933fcc32-d4c9-10cd-14b4-c179d66e27f9@abelian.org> Date: Sat, 17 Jun 2017 10:25:49 +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: <510c15eb-b57a-0ebb-9037-1f83e0652cf2@sky.com> 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: bb61bee384896e075004ae5ec954ddd2 Subject: Re: LF: Octo-soundcard for the Raspi 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: O X-Status: X-Keywords: X-UID: 11993 Terry wrote: > I have to sort out now is the timing pulse. it looks > horrible on vtscope, a sort of double humped thing I'd guess you have some high pass applied to the shaped PPS, perhaps the input stage of the Octo? Does it look anything like http://abelian.org/vlf/tmp/170617a.gif Is it possible to reduce the PPS pulse width? Say to 10mS or 5mS? > Are you using a square pulse from the GPS to feed > the RC conditioner? Yes, it's a 2mS rectangular pulse from the GPS, through a buffer (a hex inverter), then a simple RC low pass filter to shape the pulse suitably for centroid measurement. -- Paul Nicholson --