Mitsubishi MOTORS L200 1996, Руководство по ремонту, Страница: 1574 / 1723

CHASSIS ELECTRICAL –
Radio and Tape Player
FM Broadcast Good Reception Areas
10 kW
output FM
broadcast
For stereo:
20 – 25 km
For monaural:
30 – 40 km
For home stereos:
80 – 90 km
FM Signal Characteristics and Signal Interference
Multipath interference
First fading
interference
54-63
A-2 Noise appears at certain places when travelling (FM).
Do the following measures eliminate the noise?
D
Change to a different station with a strong signal to boost
resistance to interference.
D
Suppress high tones to reduce noise.
D
Extend antenna completely.
Yes
OK
No
If there is more noise than other radios, find out the noise conditions
and the name and frequency of the receiving stations from the
user, and consult with the service centre.
NOTE
About FM waves:
FM waves have the same properties as light, and
can be deflected and blocked. Wave reception is
not possible in the shadow of obstructions such
as buildings or mountains.
1.
The signal becomes weak as the distance from
the station’s transmission antenna increases.
Although this may vary according to the signal
strength of the transmitting station and
intervening geographical formation or buildings,
the area of good reception is approx. 20 – 25
km for stereo reception, and 30 – 40 km for
monaural reception.
2. The signal becomes weak when an area of
shadow from the transmitting antenna (places
where there are obstructions such as mountains
or buildings between the antenna and the car),
and noise will appear. <This is called first fading,
and gives a steady buzzing noise.>
3. If a direct signal hits the antenna at the same
time as a signal reflected by obstructions such
as mountains or buildings, interference of the
two signals will generate noise. During
travelling, noise will appear each time the
vehicle’s antenna passes through this kind of
obstructed area. The strength and interval of
the noise varies according to the signal strength
and the conditions of deflection. <This is called
multipath noise, and is a repetitious buzzing.>
4. Since FM stereo transmission and reception
has a weaker field than monaural, it is often
accompanied by a hissing noise.