Garmin GIA 63 Installation Manual page 46

2.2.3 Com Antenna Location
The GIA 63(X) COM antenna should be well removed from all projections, engines and propellers. The
ground plane surface directly below the antenna should be a flat plane over as large an area as possible
(18 inches square, minimum). The antenna should be mounted a minimum of six feet from any DME or
other COM antennas, four feet from any ADF sense antennas, and three feet from the GIA 63(X) and its
GPS antenna.
If simultaneous use of two COM transceivers is desired (split- COM or simulcomm), use of the TX
interlock function is mandatory. In addition, the COM antennas should be spaced for maximum isolation.
A configuration of one topside antenna and one bottom side antenna is recommended.
Split COM performance varies significantly across installations and is affected by both the distance
between the antennas and the separation of the tuned frequencies. In small aircraft particularly, receiver
sensitivity is typically reduced and squelch breaks are affected. Each installation should be individually
examined to determine the expected performance of split COM.
2.2.4 VOR/LOC Antenna Location
The GIA 63(X) VOR/LOC antenna should be well removed from all projections, engines and propellers.
It should have a clear line of sight if possible. The antenna must be mounted along the centerline of the
aircraft, minimizing the lateral offset.
2.2.5 Glideslope Antenna Location
The GIA 63(X) Glideslope antenna should be well removed from all projections, engines and propellers.
It should have a clear line of sight if possible.
2.2.6 Electrical Bonding
No special precautions need to be taken to provide a bonding path between the GPS antenna and the
aircraft structure. Follow the manufacturers' instructions for the COM, VOR/LOC and Glideslope
antennas.
Page 2-8 GIA 63 Installation Manual
Revision T 190-00303-05