Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id w19C56N3031340 for ; Fri, 9 Feb 2018 13:05:09 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ek7L2-00082W-9m for rs_out_1@blacksheep.org; Fri, 09 Feb 2018 11:59:32 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ek7L1-00082N-Rk for rsgb_lf_group@blacksheep.org; Fri, 09 Feb 2018 11:59:31 +0000 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 1ek7Kz-0006G8-40 for rsgb_lf_group@blacksheep.org; Fri, 09 Feb 2018 11:59:30 +0000 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=BWnXzom9EEITe3Gj+W6lUQMROmXb+FTxFTzZ07Q3wZk=; b=2JALfR34/NiYh/eVLKUGXDMC0x jZkEABlQjV9rdEjnsOVq2jOLy09EKlFQdt9c50hSYNeMhaVeLlKTSrAzeJrCPTnkEQ1mKSRsPs2ZG lgHxFCsyTCl2gqpLheDsi97aAYipc00iTcbOHr6oi8+YC+GjO7Iuc4c3lhO1et1bi8w8=; Received: from i-194-106-52-83.freedom2surf.net ([194.106.52.83]:41659 helo=pn.abelian.org) by porthos.netcom.co.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89_1) (envelope-from ) id 1ek7Kx-0003WG-Bl for rsgb_lf_group@blacksheep.org; Fri, 09 Feb 2018 11:59:27 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) by pn.abelian.org (Postfix) with ESMTP id AE65F400068 for ; Fri, 9 Feb 2018 11:59:26 +0000 (UTC) To: rsgb_lf_group@blacksheep.org References: <52dea779-7aae-aff8-1072-ad24cdcd007c@freenet.de> From: Paul Nicholson Message-ID: <4024a3ab-eb61-7801-e9ad-5715c5f49546@abelian.org> Date: Fri, 9 Feb 2018 11:59:26 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US 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-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: I'm getting about 2 degrees standard deviation of phase measurements of the 19531.25 Hz reference, taking one measurement per second. The 2 degrees equates to about 285 nS timing jitter. The PPS intervals have a mean absolute deviation between about 190 nS and 300 nS with long term average 256 nS. [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: c1f72e5acb1277e013f90c915ad7ad68 Subject: Re: LF: Testing Audioinjector Octo with RPi3 Content-Type: text/plain; charset=utf-8; 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=0.9 required=5.0 tests=FROM_ENDS_IN_NUMS 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 I'm getting about 2 degrees standard deviation of phase measurements of the 19531.25 Hz reference, taking one measurement per second. The 2 degrees equates to about 285 nS timing jitter. The PPS intervals have a mean absolute deviation between about 190 nS and 300 nS with long term average 256 nS. So the two measurements are commensurate. For a sanity check on the reference I set it to 39062.5 and allowed the VLF rx to sniff the signal with good S/N and measured a standard deviation of phase of about 0.46 degree on one second measurements, corresponding to 33 nS jitter. That really points to the sampling clock of the Octo bouncing around. The sample clock comes from a 49.152 Mhz crystal oscillator divided by 512. By way of confirmation, I replaced the Octo audio interface with a stereo Audioinjector (also from Flatmax Studios). Leaving everything else the same. With this audio interface, the PPS is showing between 20nS and 30nS jitter of the pulse centroid. -- Paul Nicholson --