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To: lml@lancaironline.net
Date: Fri, 18 May 2007 02:08:33 -0400
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From: "Bob B." <rbelshe@comcast.net>
Subject: RE: [LML] Periodic Chelton GPS Failure...Any Ideas?
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In-Reply-To: <list-2050187@logan.com>

 Jeff,
Here is another possibility.   I have heard that other com radios can also
cause this problem.


I started out with the GPS antenna for my Garmin 195 velcroed to the top of
the radio stack, just under the glare shield.  It took me a while to figure
out why I sometimes lost GPS signal. 

Turned out that when my com radio (KY-97) is tuned to certain frequencies
the receiver local oscillator radiates a signal which blocks the GPS.  I
discovered that the GPS failed whenever I was listening to Travis approach
(119.9), and when I have my KY97A tuned to this frequency (just listening,
not transmitting), the signal strength bars on the GPS drop down near zero.
Flip to a different freq. and the bars jump back up.  I have read that there
are a few other receiver frequencies that also cause this problem.

I moved the GPS antenna to the back of the airplane as far as the antenna
cable would reach and the problem went away.

Bob Belshe
Lancair 235/320  
http://home.comcast.net/~rbelshe/ 


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