Clock Setting Procedure; Radio General Information; Radio Broadcast Signals; Two Types Of Signals - Jeep 2004 Wrangler Owner's Manual

Clock Setting Procedure

1. Turn the ignition switch to the ON or ACC position
and press the time button. Using the tip of a ballpoint pen
or similar object, press either the hour (H) or minute (M)
buttons on the radio.
2. Press the H button to set hours or the M button to set
minutes. The time setting will increase each time you
press a button.

RADIO GENERAL INFORMATION

Radio Broadcast Signals

Your new radio will provide excellent reception under
most operating conditions. Like any system, however, car
radios have performance limitations, due to mobile op-
eration and natural phenomena, which might lead you to
believe your sound system is malfunctioning. To help
you understand and save you concern about these "ap-
parent" malfunctions, you must understand a point or
two about the transmission and reception of radio sig-
nals.
UNDERSTANDING YOUR INSTRUMENT PANEL 121

Two Types of Signals

There are two basic types of radio signals... AM or
Amplitude Modulation, in which the transmitted sound
causes the amplitude, or height, of the radio waves to
vary... and FM or Frequency Modulation, in which the
frequency of the wave is varied to carry the sound.

Electrical Disturbances

Radio waves may pick up electrical disturbances during
transmission. They mainly affect the wave amplitude,
and thus remain a part of the AM reception. They
interfere very little with the frequency variations that
carry the FM signal.

AM Reception

AM sound is based on wave amplitude, so AM reception
can be disrupted by such things as lightning, power lines
and neon signs.

FM Reception

Because FM transmission is based on frequency varia-
tions, interference that consists of amplitude variations
can be filtered out, leaving the reception relatively clear,
which is the major feature of FM radio.
4