Return-Path: X-Spam-DCC: paranoid 1102; Body=3 Fuz1=3 Fuz2=3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_50_60,HTML_MESSAGE,NO_REAL_NAME 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 t95MAOnV011983 for ; Tue, 6 Oct 2015 00:10:24 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ZjDqD-0008Lf-Tb for rs_out_1@blacksheep.org; Mon, 05 Oct 2015 23:02:41 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ZjDqD-0008LW-96 for rsgb_lf_group@blacksheep.org; Mon, 05 Oct 2015 23:02:41 +0100 Received: from resqmta-ch2-09v.sys.comcast.net ([69.252.207.41]) by relay1.thorcom.net with esmtps (TLSv1.2:DHE-RSA-AES256-SHA:256) (Exim 4.86) (envelope-from ) id 1ZjDp3-0007bg-VR for rsgb_lf_group@blacksheep.org; Mon, 05 Oct 2015 23:02:40 +0100 Received: from resomta-ch2-16v.sys.comcast.net ([69.252.207.112]) by resqmta-ch2-09v.sys.comcast.net with comcast id Ra151r0072S2Q5R01a1CX9; Mon, 05 Oct 2015 22:01:12 +0000 Received: from JAYDELL ([71.234.119.9]) by resomta-ch2-16v.sys.comcast.net with comcast id Ra1B1r00K0CFS1j01a1Bkl; Mon, 05 Oct 2015 22:01:12 +0000 X-DKIM-Result: Domain=comcast.net Result=Signature OK Message-ID: <00a601d0ffb9$5927d640$6401a8c0@JAYDELL> From: To: References: <560DF24D.3050309@abelian.org><0LmKOI-1aGjgI2N50-00ZuP1@mail.gmx.com> Date: Mon, 5 Oct 2015 18:01:11 -0400 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20140121; t=1444082472; bh=ZXXKHz3RUfFnYa+nX4DpJSG4+8nigKKOIrjcoiGjUvA=; h=Received:Received:Message-ID:From:To:Subject:Date:MIME-Version: Content-Type; b=f4ZOBdMQ0jZl7T5U1RBPxz7reMUNEE49JL8kjvpnzxRU2Lmb7x73caXMaIOiyrA3T 3EscAhomR9u/keMeXOwsGcLRjPzXZIHlYfHGZ+KCBeXvwvCi0R2s1syb+K/GlvyUCg 77iaztKyNsJM276XWrXgrIXyCDvKPSvpXOZL+OPl8zImtGOW4CBer8u2xamvZ3310c r5dAUg7JH2WAr5C9sOk93+iQUdTjSmnjBQTBFuDS9SBJHjJOtmeLONQ8PlKc2HO6d/ zW4f5qZcSDkaYqEXk1cx6SiuSt69ZCsyPVvLAtvEN++EpmM1hjPn0sHwNopHJtb53/ RxbN9yaSXiYUg== X-Scan-Signature: b2000330e4064ca60a9f57e731b892da Subject: Re: LF: Coherent BPSK on LF using EbNaut Content-Type: multipart/alternative; boundary="----=_NextPart_000_00A2_01D0FF97.D19C9970" 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 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 4272 This is a multi-part message in MIME format. ------=_NextPart_000_00A2_01D0FF97.D19C9970 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Andy This feature is built into Spectrum Lab ... I run 1 kHz (divided down GPS) into the sound card's right channel. Works as expected. Jay W1VD WD2XNS WE2XGR/2 ----- Original Message ----- From: Andy Talbot To: rsgb_lf_group@blacksheep.org Sent: Monday, October 05, 2015 7:27 AM Subject: Re: LF: Coherent BPSK on LF using EbNaut Continuing on this theme... Having abandonned my idea of a direct conversion Rx due to uncontrollable DC offsets, and not yet finished a locked clock for my SDR-IQ, I wondered about the next stage. The idea is to overcome errors and drift in sound cards, and ideally make any coherent receiver non-dependent on the S/Card. So I was contemplating this solution as being worthy of further tests. Once the receiver (SDR-IQ here) is locked, its output can be delivered as an audio tone whose exact frequency is known. This adjusted to end up at exactly 1kHz and is applied to one input channel of a soundcard, Now, I can generate an exact 1kHz tone by dividing down from the same reference signal and send this to the other soundcard channel. So now, we have independant reference and test inputs to the Soundcard and it doesn't matter how unstable its own clock is; the phase of the input signal can always be compared with that of the reference input. In fact, my gut feeling is that the less stable the soundcard clock is, after a bit of averaging a better result will ensue. Thoughts ? The idea of making the soundcard's clock irrelevant appeals. And generating a nice reference 1kHz tone is dead easy. Andy G4JNT ------=_NextPart_000_00A2_01D0FF97.D19C9970 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable =EF=BB=BF
Andy
 
This feature is built into Spectrum Lab = ... I run 1=20 kHz (divided down GPS) into the sound card's right channel. Works as=20 expected.
 
Jay W1VD  WD2XNS  = WE2XGR/2
----- Original Message -----
From:=20 Andy=20 Talbot
Sent: Monday, October 05, 2015 = 7:27=20 AM
Subject: Re: LF: Coherent BPSK = on LF=20 using EbNaut


Continuing on this theme...
Having abandonned my idea of a direct = conversion Rx due=20 to uncontrollable DC offsets, and not yet finished a locked clock for = my=20 SDR-IQ, I wondered about the next stage.

The idea is to overcome errors and drift in = sound=20 cards, and ideally make any coherent receiver non-dependent on the=20 S/Card.  So I was contemplating this solution as being worthy of = further=20 tests.  Once the receiver (SDR-IQ here)  is locked, =  its output=20 can be delivered as an audio tone whose exact frequency is known. =  =20  This adjusted to end up at exactly 1kHz and is applied to one = input=20 channel of a soundcard, 

Now, I can generate an exact 1kHz tone by = dividing down=20 from the same reference signal and send this to the other soundcard = channel.=20   So now, we have independant reference and test inputs to the = Soundcard=20 and it doesn't matter how unstable  its own clock is; the phase = of the=20 input signal can always be compared with that of the  reference=20 input.  In fact, my gut feeling is that the less stable the = soundcard=20 clock is, after a bit of averaging a better result will = ensue. 

Thoughts ?

The idea of making the soundcard's clock = irrelevant=20 appeals.   
And generating a nice reference 1kHz tone is = dead=20 easy.

Andy  G4JNT





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