User's Manual

INSTALLATION
MOBILE STATIONS
ENVOY™ TRANSCEIVER REFERENCE MANUAL 363
Related links:
Earthing the antenna on page 361
Earthing the transceiver in a mobile station on page 359
Poor radiation
efficiency
Poor installation Improve the earth connection.
Incorrect positioning
of the antenna
Check the position of the antenna, ensuring that the
vehicle body is not acting as a shield.
With an SWR meter in place, alter the position of the
antenna to achieve best forward-radiated power.
Check that the problem does not move to other channels.
The antenna and/or
tuner may not be
earthed correctly
Improve the earth connection.
SWR is bad The SWR
measurement may
have been performed
at the RFU rather
than at the antenna
Ensure the SWR meter is connected to the coaxial line at
the base of the antenna to achieve an accurate reading.
The antenna may not
be positioned
correctly
Check the position of the antenna, ensuring that the
vehicle body is not acting as a shield.
With an SWR meter in place, alter the position of the
antenna to achieve best forward-radiated power.
Faulty coaxial cable
or control cable
Replace faulty cables.
The antenna and/or
tuner may not be
earthed correctly
Improve the earth connection.
Voltage drop in the
fuse, the control
leads, or the battery
Voltage less than
12 V DC
Check the voltage; it must be greater than 12 V DC on
transmit.
Table 35: Possible faults in the mobile antenna installation (cont.)
Symptom Possible cause Action