Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mh01.r1000.mx.aol.com (Internet Inbound) with ESMTP id 2BA1A380000A5; Wed, 25 Apr 2012 09:47:02 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1SN2Xo-0000Ts-Kn for rs_out_1@blacksheep.org; Wed, 25 Apr 2012 14:46:08 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1SN2Xo-0000Tj-6m for rsgb_lf_group@blacksheep.org; Wed, 25 Apr 2012 14:46:08 +0100 Received: from mail-yw0-f43.google.com ([209.85.213.43]) by relay1.thorcom.net with esmtps (TLSv1:RC4-SHA:128) (Exim 4.77) (envelope-from ) id 1SN2Xm-0003i1-9G for rsgb_lf_group@blacksheep.org; Wed, 25 Apr 2012 14:46:07 +0100 Received: by yhkk6 with SMTP id k6so182180yhk.16 for ; Wed, 25 Apr 2012 06:46:04 -0700 (PDT) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=34u7Ps6VooVZq0SnGgAxfReQGMqGousttmUzgKw90AQ=; b=qyFO1XvtqdLmC3Amrhr8GgskitkEnLZt9/5c6j4vMua1fBuzk4U2xrggLDk9R3qxJ3 K6lTVMNBWpoFaQ0aKJWpu50bCAOxtQg5X1h1J/muIiCq7nAsVzx4lknzpsGKmKd01iTT OtnEQVYxNoIhbMUbH4NsJ9uUHYvn38wOwkcEdbAsNXQBuPFNaC5Mah/hyJa/xOioxm+2 keuv3vhipAIX4O+8KrdfSgVarpjWIc7xbAq+RC26kKywrDqWEZGR9L9FuYdxBAEicelp 3TtUjrWAj4BCthXpAUsM8i3PoMmrlbOzTKOgRTksLn1SRXjzbDlCPkkCx6NfWfbHdvFq Cwbw== MIME-Version: 1.0 Received: by 10.50.183.198 with SMTP id eo6mr2505096igc.61.1335361564027; Wed, 25 Apr 2012 06:46:04 -0700 (PDT) Received: by 10.231.219.131 with HTTP; Wed, 25 Apr 2012 06:46:00 -0700 (PDT) In-Reply-To: <4F97E9C2.9030000@iup.uni-heidelberg.de> References: <4F97E9C2.9030000@iup.uni-heidelberg.de> Date: Wed, 25 Apr 2012 14:46:00 +0100 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org X-Spam-Score: -0.7 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Has anyone tried using an external USB soundcard with a separate locked clock? Most work from a 12MHz crystal which can be replaces with a GPS locked source without too much effort. But I can't help wondering if there will be subsequent USB synchronisation glitches upsetting the input sampling. [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.213.43 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (andy.g4jnt[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 4e3b1488273adbbe9757d6bdd5adf219 Subject: Re: LF: Generating 8970 Hz carrier with Spectrum Lab ? 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: 0:2:393802784:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d001.2 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d60d54f980056538a X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Has anyone tried using an external USB soundcard with a separate locked clock? Most work from a 12MHz crystal which can be replaces with a GPS locked source without too much effort. But I can't help wondering if there will be subsequent USB synchronisation glitches upsetting the input sampling. Although I have used many different USB soundcards and chips, somehow never managed to get round to actually trying this myself - so hoping someone else has.... Another thing I was wondering, the soundcard chip wants 12MHz (well, the PCM2900 does anyway) and a USB hub chip can have a 6MHz crystal option. So... is there any value in synchronising this 6MHz by dividing down from the Soundcard clock. Could there still be USB slippage? My old simple 8 bit PIC serial A/D still offers an absolutely phase coherent sampling as it chucked the data up a non-coherent serial port so none of the potential slippage issues USB seems to give. Why does the nice ubiquitous USB port seem to have been a backwards step in this respect. Andy www.g4jnt.com > That can happen when multiple phase glitches occur on the PC, sound output. > Try to use a different sample rate, maybe 44100 instead of 48000. > Try to run SL exclusively, i.e. no other programs and internet usage > (everthing that may take a high CPU load) and see if it makes a difference. > The signal of DJ8WX is clear. That reduces the possible errors... > > 73, Stefan/DK7FC