Page 2298 - Foton Workshop Manual - Aumark (BJ1099)

62-246 DIAGNOSIS-AUDIO SYSTEM

Radio wave check Yes Go to the symptom

• Due to different wavelength, there is a table
big difference between radio coverage
area of AM and FM, sometimes AM
broadcast can be clearly received,
but FM dimensional sound can't. The
coverage area of FM dimensional
sound is the smallest and easy to be

influenced by electromagnetic wave.
• During the night, when the vehicle
receives two radio signal from the
same launching tower, it may lead to
phase adjustment interference, one is
to directly receive the signal from the
launching tower, the other is to receive
the signal reflected by the ionospheric
layer.
5 • Check if there is any high building or Move the vehicle to
high mountain around the vehicle, when No the place with better
there is high building or high mountain signal
there, it may absorb and reduce a part
of electromagnetic strength of signal
from the launching tower to the vehicle.

• Check if there is any large substation
and power transmission station around
the vehicle, the strong electromagnetic
interference signal sent from them will
cause the vehicles can't receive radio
signal.

• Due to the reason of their building
materials, some buildings may reflect
the radio signals, so that causes the
vehicle to receive two signals, leading
to the interference of two signals with
each other.

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