X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 02 Apr 2010 14:06:28 -0400 Message-ID: X-Original-Return-Path: Received: from qmta01.emeryville.ca.mail.comcast.net ([76.96.30.16] verified) by logan.com (CommuniGate Pro SMTP 5.3.5) with ESMTP id 4193519 for lml@lancaironline.net; Fri, 02 Apr 2010 12:45:11 -0400 Received-SPF: pass receiver=logan.com; client-ip=76.96.30.16; envelope-from=rbelshe@comcast.net Received: from omta22.emeryville.ca.mail.comcast.net ([76.96.30.89]) by qmta01.emeryville.ca.mail.comcast.net with comcast id 0g5q1e0031vN32cA1gkbeQ; Fri, 02 Apr 2010 16:44:35 +0000 Received: from desk ([76.21.53.220]) by omta22.emeryville.ca.mail.comcast.net with comcast id 0gow1e00F4l40fg8igp0p7; Fri, 02 Apr 2010 16:49:01 +0000 From: "Bob B." X-Original-To: "'Lancair Mailing List'" References: Subject: RE: [LML] GPS reception issue X-Original-Date: Fri, 2 Apr 2010 09:44:29 -0700 X-Original-Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0012_01CAD249.1735FC60" X-Mailer: Microsoft Office Outlook 11 Thread-Index: AcrSYQ3hyEaF1PWPRHiqYt2N+tYvCgAIj37w In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_0012_01CAD249.1735FC60 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Keith, Have you checked for interference from your com radio? This can happen when the receiver is tuned to certain frequencies, even when not transmitting. It will be worse when the GPS antenna is near the radio stack. I had to put my GPS antenna in the back to avoid this. Bob Belshe Moraga, CA Lancair 235/320 http://home.comcast.net/~rbelshe/ _____ From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Keith Smith Sent: Friday, April 02, 2010 5:36 AM To: lml@lancaironline.net Subject: [LML] GPS reception issue The signal reception on my Garmin 420 is really dodgy. We've tested the unit on a bench and it worked great. We've swapped the antenna, no change. We swapped the antenna cable, it actually got quite a bit worse (the old one had intermittent issues, the new one is dodgy, nearly full time.) If I route the cable 'just so', I can make it work fairly well on the ground with the canopy open, but it tends to go to hell when I close the canopy. If I unscrew and lift the glare shield about 1/2" - 1", the reception is great. The GPS antenna is attached to the top of the glare shield on the co-pilot side. I'm going to get some help from a shop in debugging this...but it seems to me that part of the canopy is either causing interference within the antenna cable, or the antenna itself. Has anyone experienced anything like this before? This is in a 360. Keith ------=_NextPart_000_0012_01CAD249.1735FC60 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable
Keith,
Have you checked for interference from your com = radio?  =20 This can happen when the receiver is tuned to certain frequencies, even = when not=20 transmitting.  It will be worse when the GPS antenna is near the = radio=20 stack.
 
I had to put my GPS antenna in the back to avoid=20 this.
 

Bob Belshe
Moraga, = CA
Lancair=20 235/320  
http://home.comcast.net/~rbelshe/ =


From: Lancair Mailing List=20 [mailto:lml@lancaironline.net] On Behalf Of Keith = Smith
Sent:=20 Friday, April 02, 2010 5:36 AM
To:=20 lml@lancaironline.net
Subject: [LML] GPS reception=20 issue

The signal reception on my Garmin 420 is really = dodgy.  We've=20 tested the unit on a bench and it worked great.  We've swapped = the=20 antenna, no change. We swapped the antenna cable, it actually got = quite a bit=20 worse (the old one had intermittent issues, the new one is dodgy, = nearly full=20 time.)

If I route the cable 'just so', I can make it work = fairly well=20 on the ground with the canopy open, but it tends to go to hell when I = close=20 the canopy. 

If I unscrew and lift the glare shield about = 1/2" -=20 1", the reception is great.  The GPS antenna is attached to the = top of=20 the glare shield on the co-pilot side.

I'm going to get some = help from=20 a shop in debugging this...but it seems to me that part of the canopy = is=20 either causing interference within the antenna cable, or the antenna=20 itself.

Has anyone experienced anything like this before? This = is in a=20 360.

Keith
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