ATR500 / P/N 500-(0XX)-(0XX) / 500-(1XX)-(1XX)
Operation and Installation
26
Dokument-Nr.: 01.1251.010.71e / Revision: 2.01
3.8 Antenna
3.8.1 Antenna
Selection
•
A VHF-COM-Antenna with an impedance of 50 Ohm is required.
•
Choose an antenna type compatible with the vehicle and the
mounting location.
•
Specified features depend on proper installation of the antenna.
3.8.2 Installation
Recommendation
•
Take note of the antenna manufacturer’s instructions.
•
For installation in composite aircrafts, ground planes are to be added.
The ground plane should be as large as possible but in any case not
smaller than 10 cm x 10 cm. If in doubt, please contact the aircraft
manufacturer.
•
Keep away three feet from any other antenna
•
Pursue mounting in vertical position under the belly in flight direction
•
For installation in gliders the installed antenna should be used.
3.9 Microphone
Settings
The settings of MIC and VOX values are essential for operation
(MIC=microphone level see 2.8.1.1, VOX= threshold level see 2.4.3)
Using VOX the threshold level is adjusted so that usual flight noise is not
transmitted to the headphones, but only an additional signal caused by
speaking will start intercom operation.
With very strong background noise or uncompensated microphones VOX
can be deactivated by setting VOX01. In this case intercom is activated
using the intercom switch (not PTT), which connects pin 12 (intercom) of
the equipment connector to GND. If required, e. g. in a tandem cockpit,
use two parallel connected PTT keys.
For operating in VOX mode pin 12 has to be connected permanently to
The HF antenna wire must not be included in any other
cable sets, for example power supply or microphone. It must
also not be placed together with other antenna wires, for
example NAV or Transponder.
