Return-Path: X-Spam-DCC: paranoid 1480; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_30_40,HTML_MESSAGE,SPF_PASS autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id u9O8UFHD008370 for ; Mon, 24 Oct 2016 10:30:15 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1byaah-00059q-Lp for rs_out_1@blacksheep.org; Mon, 24 Oct 2016 09:26:43 +0100 Received: from [195.171.43.34] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1byaah-00059h-4d for rsgb_lf_group@blacksheep.org; Mon, 24 Oct 2016 09:26:43 +0100 Received: from smtp04.smtpout.orange.fr ([80.12.242.126] helo=smtp.smtpout.orange.fr) by relay2.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.87) (envelope-from ) id 1byaae-00018P-9P for rsgb_lf_group@blacksheep.org; Mon, 24 Oct 2016 09:26:42 +0100 Received: from xps.home ([90.3.240.175]) by mwinf5d60 with ME id zLSe1t0073nlUQy03LSemZ; Mon, 24 Oct 2016 10:26:38 +0200 X-ME-Helo: xps.home X-ME-Date: Mon, 24 Oct 2016 10:26:38 +0200 X-ME-IP: 90.3.240.175 Date: Mon, 24 Oct 2016 10:26:37 +0200 From: Michel Brunel X-Priority: 3 (Normal) Message-ID: <411225225.20161024102637@mterrier.net> To: rsgb_lf_group@blacksheep.org In-Reply-To: References: <157b3bf43d2-111e-bfa3@webprd-a11.mail.aol.com> <0f1b59cf-e10d-1daf-125b-ad4aca471a06@gmail.com> <580205DC.80508@posteo.de> <58020BE2.1020107@posteo.de> <289454467.20161015210855@chriswilson.tv> <5808C23D.6060006@posteo.de> <580CE812.40500@posteo.de> <580CEA96.2010200@posteo.de> <4e343fa907bf9f2652ce9f25fe56d62a@smtp.hushmail.com> MIME-Version: 1.0 X-Scan-Signature: 968492e608ae81f946d7c13a3d073eeb Subject: Re: LF: Idiot's guide to receiving Ebnaut? - Tutorial part2 Content-Type: multipart/alternative; boundary="----------02E06F24F19CF91F2" 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 2.56 on 10.1.3.11 Content-Length: 3661 Status: O X-Status: X-Keywords: X-UID: 9173 ------------02E06F24F19CF91F2 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Andy, Has anyone tried locking an external USB soundcard to GPS? Chips such as t= he PCM290x family use their own 12MHz crystal, and it's relatively straight= forward to provide 12MHz locked to some master reference like GPS to drive = this. Yes, I tried that with a Behringer UCA202 soundcard and its quite straightf= orward. Unfortunately the PCM290x chip has a builtin PLL to generate an int= ernal 96 MHz clock and there is an awful PLL jitter which makes the chip un= susable for Ebnaut.=20 Best to consider your PIC solution to sample and decimate the audio samples= . Just wondering if the PIC16F876 I have in my junk box can be used instead= of the PIC16F819 ... Michel - f5wk So, in theory, the 48000 and lower sampling rates will then be spot-on. Ho= wever, I fear there may be slippages in the USB interface as the 12MHz exte= rnal clock, and the USB's 6MHz clock slip past each other, resulting is los= t packets and corrupted data samples I do use a homebrew PCM2900 soundcard for data comms work, but never tried = locking it. Instead, for LF work I instead use the external digitiser, sen= ding data to the PC on a RS422 interface; as described in the link sent ear= lier. The PIC digitiser, working on a 1kHz tone, can be used with any suita= ble receiver Andy G4JNT -- ------------02E06F24F19CF91F2 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable Re: LF: Idiot's guide to receiving Ebnaut? - Tutorial pa= rt2 Andy,


 Has anyone tri= ed locking an external USB soundcard to GPS?  Chips such as the PCM290= x family use their own 12MHz crystal, and it's relatively straightforward t= o provide 12MHz locked to some master reference like GPS to drive this.


Yes, I tried that = with a Behringer UCA202 soundcard and its quite straightforward. Unfortunat= ely the PCM290x chip has a builtin PLL to generate an internal 96 MHz clock= and there is an awful PLL jitter which makes the chip unsusable for Ebnaut= . 

Best to consider your PIC solution to sample and decimate the audio samples= . Just wondering if the PIC16F876 I have in my junk box can be used instead= of the PIC16F819 ...

Michel - f5wk

So, in theory, the= 48000 and lower sampling rates will then be spot-on.  However, I fear= there may be slippages in the USB interface as the 12MHz external clock, a= nd the USB's 6MHz clock slip past each other, resulting is lost packets and= corrupted data samples

I do use a homebrew PCM2900 soundcard for data comms work, but never tried = locking it.  Instead, for LF work I instead use the external digitiser= , sending data to the PC on a RS422 interface; as described in the link sen= t earlier. The PIC digitiser, working on a 1kHz tone, can be used with any = suitable receiver

Andy  G4JNT







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