F.u.n.k.e. F10185, Installation & Operation Manual

Page: 26 / 81

FSG 90 System
3 Installation
20
FAV_D10024 December 2014
3.5.3 Antenna installation
Your radio
FSG 90(X)
is only as good as the antenna!
For operation, a vertical polarized 50-Ohm broadband aircraft COM antenna is required.
The antenna must be able to radiate RF energy evenly and omnidirectional:

First of all, look up the aircraft's manual for antenna installation instructions.

The antenna installation location must be carefully planned. It would be the best to
consult the aircraft certifying inspector. In order to achieve best results into all
directions, installation instructions must be fully complied with.

For aircraft with metal fuselage, we recommend a rod antenna. The antenna is
mounted vertically (as possible) on or under the fuselage. Location should be even
away from horizontally screening metal parts like propeller, undercarriage, vertical
metal fins etc., for maximum radio range into all (horizontal) directions.

Distance to other aircraft antennas, like another COM, NAV antenna, should be at
least 1.5 m/5 ft. When using two radios
FSG 90(X)
, a distance of 1 m/3.3 ft. between
COM antennas is sufficient.

The antenna mounting area should be as flat as possible.

The metallic contact between aircraft surface/structure and the antenna cable outer
conductor (shield) must be robust. The electrical contact shall remain continuously
good safe against vibration.

For wood and fiberglass (GRP) aircraft, 3 or 4 aluminium counter weight strips (ea.
60 cm/2 ft. long - 5 cm/2 in. wide) are recommended, but shall be placed (mostly)
horizontally with a (if possible rectangular) shape as a star or cross.

These as star or cross placed counter weights must be centrally screwed together
with the antenna socket, with continuous, electrically good contact.

Alternatively, for aircraft with non-metallic surface structure inside the fuselage, a
metal foil (min. 60 x 60 cm/2 ft. x 2 ft.) can be stuck in. The antenna socket will then
be placed in the foil centre, together with a metallic ground contact support plate.

For aircraft with fuselage and/or tail-fin made of non-conductive material, a vertical
folded top antenna is suitable. Installation is made preferably during manufacturing
the tail-fin.
IMPORTANT: Carbon fibre is conducting and may shield the antenna!

Careful sealing of all openings of the outer skin is mandatory. Make sure, that
electrical contacts remain continuously good, even under bad environmental
conditions.

Use only high quality 50-
Ω coax cable type RG-58C/U. Avoid any sharp cable bend
(radius > 50 mm), and any excessive coax cable length.

Place all wiring including antenna cable distant to other wiring which carries heavy AC
currents, and distant to any aircraft controls.