Becker Designed AR 3201 - Manual (Page 22)

2.6 Testing after installation
2.6.1 Ground testing with engine OFF
After installing the transceiver, measure antenna matching between antenna base and antenna feeder
by means of a VHF reflection meter (voltage/standing-wave meter).
Over the complete frequency range of the transceiver, the voltage/standing-wave ratio must be within
the value 3 : 1. Exceeding this value is an indication of mismatch, which can be due to a wrong or
inadequate counterweight.
After antenna measurement, carry out a voice test with the ground station.
2.6.2 Ground testing with engine ON
With the engine running make sure that the aircraft voltage is within the permissible tolerances at
approx. 14 V. Make the test at engine cruising speed. Carry out speech test at a long distance away
from the ground station. At engine cruising speed the cabin noise of the aircraft must only be heard
muted thus making for clear, intelligible conversation. Hold microphone close to lips when speaking.
Switch on intercommunications by means of the IC switch (when provided) and carry out speech test
at engine cruising speed.
If necessary, correct volume by means of IC control (see Fig. 2-7).
Apply squelch switch and check squelch function. The squelch threshold can be set from without by
means of the squelch control.
CAUTION
In speaker operation no acoustic feedback should occur via the sidetone. If necessary, turn down
sidetone by means of the SIDETONE control.
Fig. 2-7 Location of IC control
AR 3201 - ( )
Page 2-8 DV 28110.03/.04 Issue 04/92