X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 07 Jul 2008 08:39:12 -0400 Message-ID: X-Original-Return-Path: Received: from wind.imbris.com ([216.18.130.7] verified) by logan.com (CommuniGate Pro SMTP 5.2.5) with ESMTPS id 3013718 for lml@lancaironline.net; Sun, 06 Jul 2008 10:56:41 -0400 Received-SPF: none receiver=logan.com; client-ip=216.18.130.7; envelope-from=brent@regandesigns.com Received: from [192.168.1.144] (cbl-238-80.conceptcable.com [207.170.238.80] (may be forged)) (authenticated bits=0) by wind.imbris.com (8.14.2/8.12.11.S) with ESMTP id m66Ettms065596 for ; Sun, 6 Jul 2008 07:56:01 -0700 (PDT) (envelope-from brent@regandesigns.com) X-Original-Message-ID: <4870DCF3.9070906@regandesigns.com> X-Original-Date: Sun, 06 Jul 2008 07:55:47 -0700 From: Brent Regan User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.2) Gecko/20040804 Netscape/7.2 (ax) X-Accept-Language: en-us, en MIME-Version: 1.0 X-Original-To: Lancair Mailing List Subject: Re: Re: WAAS antennas Content-Type: multipart/alternative; boundary="------------090806040900000907080608" This is a multi-part message in MIME format. --------------090806040900000907080608 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit The WAAS signal is not transmitted by "conventional" GPS satellites, rather, it is transmitted from geostationary telecommunication satellites. Consequently the signal does not behave like the signal from the orbiting GPS satellite constellation. Also, there can ne a dozen or more GPS satellites in view with only 4 needed for a fix but there are only two WAAS satellites with one being needed for a WAAS approach. Bottom line is that is WAAS is intermittent then it is likely the antenna location or signal path to your GPS' RF section (line of sight, antenna, connectors or Coax cable). Mounting the antenna inside the aircraft will frequently cause problems due to the fuselage shading the WAAS signal to the antenna. If I hang a GPS antenna out the lab's eastern window I can get a good fix from the satellites to the northeast but no WAAS. Regards Brent Regan --------------090806040900000907080608 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit The WAAS signal is not transmitted by "conventional" GPS satellites, rather, it is transmitted from geostationary telecommunication satellites. Consequently the signal does not behave like the signal from the orbiting GPS satellite constellation. Also, there can ne a dozen or more GPS satellites in view with only 4 needed for a fix but there are only two WAAS satellites with one being needed for a WAAS approach.

Bottom line is that is WAAS is intermittent then it is likely the antenna location or signal path to your GPS' RF section (line of sight, antenna, connectors or Coax cable).

Mounting the antenna inside the aircraft will frequently cause problems due to the fuselage shading the WAAS signal to the antenna.

If I hang a GPS antenna out the lab's eastern window I can get a good fix from the satellites to the northeast but no WAAS.

Regards
Brent Regan
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