From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from plane.gmane.org ([80.91.229.3]:40921 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753333Ab2D1UkK (ORCPT ); Sat, 28 Apr 2012 16:40:10 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1SOER7-0008In-1D for linux-media@vger.kernel.org; Sat, 28 Apr 2012 22:40:09 +0200 Received: from d67-193-214-242.home3.cgocable.net ([67.193.214.242]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 28 Apr 2012 22:40:09 +0200 Received: from brian by d67-193-214-242.home3.cgocable.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Sat, 28 Apr 2012 22:40:09 +0200 To: linux-media@vger.kernel.org From: "Brian J. Murrell" Subject: Re: HVR-1600 QAM recordings with slight glitches in them Date: Sat, 28 Apr 2012 16:39:58 -0400 Message-ID: <4F9C559E.6010208@interlinx.bc.ca> References: <1335307344.8218.11.camel@palomino.walls.org> <1335624964.2665.37.camel@palomino.walls.org> <4F9C38BE.3010301@interlinx.bc.ca> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig33E6F1A985250AECA664E24E" Cc: Devin Heitmueller , stoth@kernellabs.com In-Reply-To: <4F9C38BE.3010301@interlinx.bc.ca> Sender: linux-media-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig33E6F1A985250AECA664E24E Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 12-04-28 02:36 PM, Brian J. Murrell wrote: > One more question... And to answer my own question, and provide some more data... > I've never gotten my mind around SNRs and dBs, etc. Generally speaking= , > am I looking for these "snr" values to go up or down (i.e. closer to 0 > or further away) to make my signal better? Clearly, bigger numbers are better. When I hook my HVR-1600 directly up to the cable connection coming into the house with a 25 foot cable and a barrel connector the SNR goes up to "148" (32.8 dB) so that's my ceiling. I can't leave it hooked up like this for anything more than a few minutes so I can't be sure that's a high enough SNR for me to get perfect recordings every time. If I add one two way splitter to the incoming cable with one feed going off to my cable modem and one to the HVR-1600, the SNR drops to "145" (32.5 dB). But again, I can't really leave it like that for too long. so splitting that leg of the 2-way split 3 more times through a 3 way splitter reduces the SNR at the HVR-1600 to between "142" and "145" (32.2 - 32.5 dB). I typically have one more splitter downstream from that 3 way splitter which is a 4 way splitter to feed all of the tuners on my Mythtv box and introducing that splitter reduces the SNR at the HVR-1600 to between "13c" and "13e" (31.6 - 31.8 dB). I have no idea where in these range of values "acceptable" is though. Given that the HVR-1600 seems to be more sensitive to signal quality that just about anything else in here, I suppose I could feed it more directly from a split closer to the source signal. Cheers, b. --------------enig33E6F1A985250AECA664E24E Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk+cVZ4ACgkQl3EQlGLyuXCKZwCgpiBQDblyk/3Fdp/ZkntTF1p7 l0sAoLoDRN6AiD/XYC81cmLF5U/R1XXJ =navW -----END PGP SIGNATURE----- --------------enig33E6F1A985250AECA664E24E--