Kenwood TM-221A Instruction Manual page 27

8-2. MOBILE INSTALLATION HINTS
8-2-1.Noise Reduction
In motor vehicles, noise is generated by the ignition
system. Other sources of noise include the wiper
and heater motors.
It is imperative that some preventive measures be
taken to reduce the noise to the lowest possible
level.
(a) Antenna location selection
Since ignition noise is generated by the vehicles
engine, the antenna must be installed as far from
the engine as possible.
(b) Bonding
The component parts of motor vehicles, such as
the engine, transmission, muffler system, ac-
celerator, etc., are coupled to one another at DC
and low frequencies, but are isolated at high fre-
quencies. By connecting these parts using
heavy, braided ground straps, ignition noise can
be reduced. This connection is called bonding''.
(c) Use ignition suppressor cable or suppressor
spark plugs
Noise can be reduced by using spark plugs with
internal resistors, or resistive suppressor ignition
cable.
8-2-2. Battery Capacity
The power system of a motor vehicle is comprised of
a battery and an alternator (which generates power
while the engine is running) to supply current to
loads or to charge the battery.
Since the transceiver draws high current during
transmit, care should be exercised so the power
system is not overloaded. When using the
transciever, the following points should be observed
from the viewpoint of battery maintenance:
(a) Turn the transceiver OFF when the lights,
heater, wipers and other high-draw accessories
are used.
(b) Avoid transceiver operation when the engine is
not running.
(c) If necessary, use an ammeter and/or a voltmeter
to check battery condition.