PS Engineering PDA360EX Installation Manual - Manual (Page 23)

PS Engineering Inc. ®
PAR100EX Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-760-0000 Page 2-16 Rev. 12, Jan. 2014
6. Install qty. 1 short thread screw to the rear of the unit.
2.13 Communications Antenna Installation Notes
2.13.1 Metal Skin Aircraft
For metal skin aircraft a ¼ wave whip is the easiest antenna to fit. Ensure that the antenna base and the
coax shield are firmly grounded to the skin of the airframe, on the inside of the aircraft. Ensure that any
anti-corrosion product, which may be used to seal the exterior surface, does not isolate the antenna base
from the airframe.
For best performance, the whip should be straight and vertical, when mounted
on the airframe.
Refer to the Microair Avionics website
www.microair.com.au for more detail on antennas suitable for
metal skin airframes.
2.13.2 NON-METAL SKIN AIRFRAMES
For non-metal airframes, a ¼ wave whip may still be used, but a ground plane must be installed, on the
inside face of the aircraft skin. The ground plane should ideally be circular, and as a minimum, have a
diameter of half the height of the whip. The ground plane should be fabricated from a lightweight metal,
eg thin aluminum sheet. For best performance, the whip element should be as vertical as possible. An al-
ternative antenna for non-metal airframes is the Ground Plane independent dipole. This antenna is physi-
cally similar to the ¼ wave whip, but has a small flexible stub antenna pointing downwards from the an-
tenna base. The stub section of the antenna takes the place of the ground plane, and simplifies installation.
Avoid mounting locations which position the antenna parallel to nearby metallic airframe structures such
as tube framing, brackets, ribs, or frames. Metal objects which are close and parallel to the antenna will
adversely affect performance. If the installation has two radios, the two antennas should be separated hori-
zontally by at least the length of the antenna. In the case of airband antennas this should be approx 1m
(3ft). The further apart the better.