User's Manual

INSTALLATION
MOBILE STATIONS
362 ENVOY™ TRANSCEIVER REFERENCE MANUAL
Tuning a mobile antenna
A mobile antenna uses an automatic tuner to make the physically small whip appear
larger to the transceiver.
To tune a mobile antenna:
 Scroll to the channel on which you want to transmit, then press PTT to tune.
Troubleshooting the mobile antenna
Common problems caused by incorrect installation are listed in Table 35.
WARNING: Before using the antenna system see the safety information provided.
WARNING: Poor installation can damage the antenna beyond repair.
Table 35: Possible faults in the mobile antenna installation
Symptom Possible cause Action
Antenna tunes when
stationary, but fails
when mobile
Incorrect positioning
of the antenna on the
vehicle
Ensure correct installation and tuning procedures are
followed.
With an SWR meter in place, alter the position of the
antenna to achieve best forward-radiated power.
Carry out all testing in the open, away from trees and
buildings etc. Leaning the antenna away from the
bodywork sometimes assists in tuning. Check that the
problem does not move to other channels.
Antenna fails to tune
certain channels
The antenna and/or
tuner may not be
earthed correctly
Improve the earth connection.
Ensure a good earth connection to the vehicle body is
provided by an earth braid or copper strap, keeping it as
short as possible.
Check the vehicle earth on metal areas close to the
antenna and rectify if necessary, for example, the bonnet
of the vehicle may be isolated from the main vehicle
earth.
If the problem persists, shorten or lengthen the coaxial
cable between the antenna and the transceiver by
approximately 1 m (1 yd).
Check that the problem does not move to other channels.
The antenna may
have been tuned
without the whip in
place
Ensure the whip is in place before tuning.