Kenwood TM-255A Instruction Manual page 9

{ INSTALLATION AND CONNECTION
DC POWER CABLE CONNECTION
Route the DC power cable directly to the vehicle's
battery terminals using the shortest path from the
transceiver. It is not recommended to use the
cigarette lighter socket since some cigarette lighter
sockets introduce an unacceptable voltage drop.
To prevent the risk of short circuits, disconnect other
wiring from the negative (—) battery terminal before
connecting the transceiver. Confirm the correct
polarity of the connections before attaching the power
cable; red connects to the positive (+) terminal, black
connects to the negative (—) terminal. Use the full
length of the cable without cutting off the excess even
if the cable is longer than required. In particular,
never remove the fuse holder from the cable. After
completing transceiver connections to the battery,
then reconnect any wiring removed from the negative
terminal.
To Antenna
a —
ie 00 Le { Ground
Fuses (20A) 7
Red
Black
Speaker
12 V battery
If the power cable must be routed through a hole in
the vehicle chassis or body, for example in the firewall
at the front of the passenger compartment, use a
rubber grommet to protect the cable from abrasion.
The entire length of the cable must be dressed so it is
isolated from heat and moisture. After the cable is in
place, wind heat-resistant tape around the fuse holder
to protect it from moisture. Tie down the full run of
cable.
The vehicle battery must have a nominal rating of
12 V. Never connect the transceiver to a 24 V
battery. Be sure to use a 12 V vehicle battery that
has sufficient current capacity. If the current to the
transceiver is insufficient, the Display may darken
during transmission (at audio peaks during SSB
operation), or transmitter output power may drop
excessively.
Note:
@ /f you use the transceiver for a long period when the vehicle
battery has not been fully charged, or when the engine has
been stopped, the battery may become discharged, and will not
have sufficient reserves to start the vehicle. Avoid using the
transceiver under these conditions.
@ Replace blown fuses only after investigating and correcting the
cause of the failed fuse. Always replace a blown fuse by anew
fuse with the specified ratings.
m Replacing Fuses
If the fuse blows, determine the cause then correct
the problem. After the problem is resolved, only
then replace the fuse. If newly installed fuses
continue to blow, disconnect the power plug and
contact your dealer or nearest Service Center for
assistance.
| Function | Fuse Current |
Transceiver Power Cable 15A
DC Power Cable 20A
CAUTION: Only use fuses of the specified type and rating.
ANTENNA CONNECTION
Before operating mobile, you must first install an
efficient, well-tuned antenna. The success of your
mobile installation will depend largely on the type of
antenna and its correct installation. The transceiver
can give excellent results if the antenna system and
its installation is given careful attention.
Your choice of 144 MHz or 430 MHz antenna should
have a 50 ohm impedance to match the transceiver
input impedance. Use low-loss coaxial feed line that
also has a characteristic impedance of 50 ohms.
Coupling the antenna to the transceiver via feed line
having an impedance other than 50 ohms reduces the
efficiency of the antenna system, and can cause
interference to nearby broadcast television and radio
receivers.
CAUTION: Transmitting without an antenna or other matched
load connected may damage the transceiver. Always connect the
antenna to the transceiver first before transmitting.
GROUND CONNECTION
The ground, which is the other half of the antenna
system, is very important when using most mobile
antennas. Connect the feed line ground for the
antenna securely to the vehicle's chassis, and be
certain to bond (electrically connect) the vehicle body
to the chassis. The sheet metal will provide the
primary ground plane, so be sure to establish a good
RF connection from the feed line to both the chassis
and the body. For comprehensive information on
mobile antennas and their successful installation and
optimization, refer to any of the publications on the
subject available at dealers handling Amateur
supplies.
If your car has plastic bumpers, make sure to ground
the antenna mount to the body and the chassis of the
car.