Return-Path: Received: (qmail 16017 invoked from network); 28 Dec 2003 15:36:29 -0000 Received: from unknown (HELO ptb-mxscan03.plus.net) (212.159.14.237) by ptb-mailstore01.plus.net with SMTP; 28 Dec 2003 15:36:29 -0000 Received: (qmail 27529 invoked from network); 28 Dec 2003 15:36:29 -0000 X-Filtered-by: Plusnet (hmail v1.01) X-Spam-detection-level: 11 X-Priority: 3 X-MSMail-Priority: Normal Received: from ptb-mxcore03.plus.net (212.159.14.217) by ptb-mxscan03.plus.net with SMTP; 28 Dec 2003 15:36:26 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore03.plus.net with esmtp (Exim) id 1Aacxu-000736-E3 for dave@picks.force9.co.uk; Sun, 28 Dec 2003 15:36:26 +0000 X-Fake-Domain: majordom Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1AacwO-0006Fs-2b for rs_out@blacksheep.org; Sun, 28 Dec 2003 15:34:52 +0000 Received: from [165.212.11.110] (helo=cmsrelay01.mx.net) by post.thorcom.com with smtp (Exim 4.14) id 1AacwK-0006FV-9f for rsgb_lf_group@blacksheep.org; Sun, 28 Dec 2003 15:34:48 +0000 Received: from uadvg129.cms.usa.net (165.212.11.129) by cmsoutbound.mx.net with SMTP; 28 Dec 2003 15:34:17 -0000 Received: from usa.net [151.38.68.203] by uadvg129.cms.usa.net (ASMTP/dibene@usa.net) via mtad (C8.MAIN.3.11E) with ESMTP id 115HLbPIN0080M29; Sun, 28 Dec 2003 15:34:13 GMT X-USANET-Auth: 151.38.68.203 AUTH dibene@usa.net usa.net Message-ID: <3FEEF805.3020704@usa.net> Date: Sun, 28 Dec 2003 16:34:29 +0100 From: "Alberto di Bene" User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 (ax) X-Accept-Language: en-us, en MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <31.425fc1cf.2d1f581b@aol.com> In-reply-to: <31.425fc1cf.2d1f581b@aol.com> Subject: LF: Re:: Sat-TV timebase Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 8bit X-Spam-Checker-Version: SpamAssassin 2.60 (1.212-2003-09-23-exp) on post.thorcom.com X-Spam-Level: **** X-Spam-Status: No, hits=4.3 required=5.0 tests=FAKE_HELO_USA_NET,HTML_30_40,HTML_MESSAGE,HTML_TITLE_EMPTY,MIME_HTML_ONLY autolearn=no version=2.60 X-SA-Exim-Scanned: Yes Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-PN-SPAMFiltered: yes X-Spam-Rating: 1 Thanks Markus for the detailed info about your observations.
Giving that both ZDF and 3sat are available here only via a satellite link, I think that
the GPS 1pps way is still the better to follow. I just wanted to avoid to install a fixed
GPS antenna on my roof, but it looks like I will have to.

73 Alberto I2PHD

MarkusVester@aol.com wrote:

Hi Alberto and LF group,

the Astra downlink I observed was analog FM (10964MHz horizontal). The satellite signal was an exact, but delayed replica, with apparently no buffering. The only problem is that the path delay has some daily Doppler variation due to the small excentricity and inclination of the not-quite geostationary orbit. During my comparisons in November 2001, this shift amounted up to about 50µs peak-peak over 24h. Furthermore, the time-shift is not easily predictable, as tidal effects and occasional correction maneuvers cause a day-to-day variation in the orbital parameters. - If you can receive terrestrial ZDF, one very crude but enlightening experiment is to simply combine the two video sources via different resistors and watch the weaker signal's sync-bar wander across the screen in the course of a day.
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