4. Installation Overview
air
avionics
4.4 Antenna Considerations
Good antenna placement and installation is important. FLARM signals are transmitted with
very low power. Therefore, a good antenna installation is critical for equipment performance.
Also the 1090 MHz and GPS antennas do have to be installed following certain requirements.
If antennas are not installed in an optimum position, range and coverage are limited.
Cockpit antennas for installation inside the cockpit are included with delivery of AT-1 (dipole
antennas). Cockpit antennas are fairly easy to install and in some aircraft types provide
decent results. Yet, depending on the signal type, external antennas are recommended.
4.4.1 Antenna cable installation
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Route the antenna cable as appropriate, avoid sharp bends.
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Secure all cables in order to minimize vibration.
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The antenna cable should not be located near flight control cables and controls.
•
The antenna cables must never be squeezed or chafed.
4.4.2 FLARM Antennas
In Europe, FLARM signals are transmitted with an output power of roughly between 10 and
25mW. This is about 10,000 times weaker than a typical transponder signal or 200 times
weaker than a VHF radio. Therefore, especially the FLARM antenna installation is crucial.
Please ensure that all of the below-mentioned requirements are met as closely as possible.
FLARM Cockpit Antennas
The FLARM cockpit antenna included with delivery is a dipole antenna that has an adhesive
pad in the center.
1. Always install FLARM antennas vertically.
2. Ensure that the antenna cable is routed away from the antenna in an orthogonal way
in the first 15 cm (6 inches) or use angled antenna connectors.
3. Do not coil the antenna cable. Make sure it is as short as possible. Only experts with
professional tools may shorten the FLARM antenna cable.
4. Ensure that no conductive parts (metal, carbon fiber) are close to the antenna.
5. Install the antenna in a location where it has a clear view and is not obstructed by
structural parts.
6. If using multiple FLARM antennas, please make sure that they are located far away
from each other to increase coverage. The reception range is not increased by
multiple antennas, only the reception coverage is increased. Therefore, it makes little
sense installing two FLARM antennas closely to each other, because then they cover
the same area. Ensure that both antennas cover different areas for good results, e.g.
on the top and on the bottom of the aircraft fuselage.
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AT-1
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Installation Manual
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rev. 4.0
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2020/01/09