Insignia IN-CD101, Owner'S Manual, Page: 15 / 15

15
Ignition
The most common source of noise in
reception is the ignition system. This is
normally due to the fact that radio is
placed relatively close to the ignition
system (engine). This type of noise can be
easily detected because it will vary in
intensity of pitch with the speed of the
engine.
Usually, the ignition noise can be
suppressed considerably by using a radio
suppression type high voltage ignition wire
and suppressor resistor in the ignition
system. (Most vehicles employ this wire
and resistor but it may be necessary to
check them for correct operation.) Another
method of suppression is the use of
additional noise suppressors. These can
be obtained from most CB/A mateur radio
or electronic supply shops.
Interference
Radio reception in a moving environment
(automobile) is very different from
reception in a stationary (home). It is very
important to understand the difference.
AM reception will deteriorate when
passing through a tunnel or when passing
under high voltage lines. Also, noise can
be picked up from passing automobiles.
Although AM is subject to environmental
noise, it has the ability to received at great
distance. This due the fact that
broadcasting signals follow the curvature
of the earth and are reflected back by the
upper atmosphere.
FM reception is just the opposite of AM. It
is not subject to environmental noise and
it does have the ability to be received at
great distances (usually 30 miles). Also,
tall buildings, mountains, or hills can block
the FM signal.
To reduce the possibility of these
problems, ALWAYS FINE TUNE a station,
and if possible, set the antenna height to
30 inches.
CAUTION
1. This unit is designed to operate on
12-volts DC, negative ground electrical
system only. Do not attempt to install
this unit in a vehicle having a positive
ground system.
2. You should not touch the high-polished
playback head with any metallic or
magnetic tools.
3. Your unit has built-in filtering to
eliminate most of the noise that might
come through the power source.
However, with some vehicles,
particularly older models, some clicking
or other unwanted noise might be
present.
IGNITION AND INTERFERENCE NOISE