Remi,
Thanks for the info. I think I have the solution. Probably a couple of things
and
not just one.
Al Stills
N725AZ
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com]On Behalf Of Rmi Guerner
Sent: Monday, December 18, 2006 3:57 AM
Subject: Europa-List: ground plane
Hi Al,
I have been looking at the antennas on composites airplanes (Lancairs, Glasairs,
etc) for years and the fact is that most builders install all antennas inside
the airframe for obvious drag reduction, except for XPDR and DME antennas.
Of course I am talking about glass, not carbon fiber airframes. XPDR and DME
works
in the 1030- 1090 MHz frequency range and are therefore more sensitive to
shadowing and any less than perfect installation. Best practice is to install
the antenna outside, pointing downwards, on the belly of the aircraft, with
the appropriate ground plane. Minimum size of the ground plane is 4 wave length
in diameter. 10 inch diameter, .025 inch thick aluminum is suggested in the
litterature. Another thing is to make sure your BNC connectors (both center
wire and shielding) are soldered not just crimped, as this warrants a better
contact
in the long term and a better reliability.
Good flights
Remi
From: "AlStills" <astills@cox.net>
Subject: Europa-List: Ground Plane
Hi all,
I've been having a little problem with ATC reading my transponder all the
time. I suspect a bit of shadowing.. I have the 2 1/2"-3" transponder
antenna mounted
upside down on a shelf on the rear corner of the baggage bay. I have a 6"
steel ground plane mounted to the antenna. What size ground plane have
others used
successfully and where is your antenna mounted. ATC reads me better out of
KGEU with a feed from Luke AFB while KDVT (where I'm hangered) gets their
feed
---From Phoenix Sky Harbor airport. By far KDVT is worse than KGEU. I know
there is difference in the feed from the different radars but need to get
rid of most of the
shadowing if possible. Sure would make me more presentable to the guys at
KDVT. (One of the busiest GA ariports in the nation)
Have about 8 hrs on the plane now and the grin is still in place. Gets even
bigger the more I fly!
Al Stills
N625AZ
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