Fm Reception Characteristics - Eclipse CD5423 Owner's Manual

How to operate the tuner

FM reception characteristics

In general, FM has much better tonal quality than AM. However, FM
and FM stereo reception encounter several characteristic problems
not encountered with AM. FM is more difficult to receive than AM in a
moving vehicle. The following are explanatory notes on what to
expect from FM reception and on how to get satisfactory
performance.
FM RECEPTION DIFFERS FROM AM
A characteristic of transmitted signals is that lower frequencies
travel further. FM frequencies are much higher than AM's
(similar to a ray of light): they won't bend but they will reflect.
Often, they will be interrupted by tall buildings, mountains, etc.,
taking direct and indirect paths to your vehicle's antenna. The
distance at which FM stations can be received satisfactorily is
usually not nearly as far as that which AM stations can be
received.
AM Radio Waves
Ionosphere
FADING OUT
In weak signal or "fringe" reception areas, FM stations may
fade out completely, or fade in and out. When driving in weak
signal areas, such as near hills, through valleys or tunnels,
among tall buildings, etc., you may encounter unusual noise
interference. THIS IS NOT A TUNER PROBLEM. In this case,
you can only wait until you are in a better reception area, tune
to a stronger station, or reduce the treble level.
FM Radio Waves
Ionosphere
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