radio antenna MITSUBISHI 3000GT 1996 2.G Owner's Manual

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iCHASSIS ELECTRICAL
- Radio and Tape Player54-155
COMPONENT LOCATIONMotor antenna control unit ___
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A-2Noise appears at certain places when traveling (FM).Do the following measures eliminate the noise?
YeslChange to a different station with a strong signal to boost resistance to interference.l Suppress high tones to reduce noise.+3cll Extend antenna completely. (Whip antenna)
No
tIf 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 center.
NOTE
About FM waves:
FM waves have the same properties as light, and
can be deflected and blocked. Wave reception isnot 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 interven-ing geographical formations or buildings, the
area of good reception is approx.
20-25 km
(12-l 6 miles) for stereo reception, and 30-40km (19-25 miles) 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
3.
4.
or buildings between the antenna and.the car),
and noise will appear. and gives a steady buzzing noise.>
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 traveling,
noise will appear each time the vehicle’s anten-
na passes through this kind of obstructed area.The strength and interval of the noise varies
according to the signal strength and the condi-tions of deflection.
noise, and is a repetitious buzzing.>Since FM stereo transmission and reception
has a weaker field than monaural, it is often
accompanied by a hissing noise.FM Broadcast Good Reception Areas
FM Signal Characteristics and Signal Interference
For home stereos:80-90 km (SO-56 miles):.:,.::..:,.::.‘; .: ‘, “.‘l’.. ”216AO664Z16A066300002401
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iA-3Mixed with noise, only at night (AM).
L
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The following factors can be considered as possible
causes of noise appearing at night.1. Factors due to signal conditions: Due to the
fact that long-distance signals are more easily
received at night, even stations that are received
without problem during the day may experience
interference in a general worsening of reception
conditions. The weaker a station is the more
susceptible it is to interference, and a changeto a different station or the appearance of a
beating sound* may occur.
Beat sound*: Two signals close in frequency
interfere with each other, creating a repetitious
high-pitched sound. This sound is generated
not only by sound signals but by electrical waves
as well.
2.Factors due to vehicle noise: Generator noisemay be a cause.
the
lamps OFF?
Yes
t1 Do the following measures eliminate the noise? 1 yes cl/l Tune to a station with a strong signal.
l
Tune to a station with a strong signal without com-cletelv extending the antenna.
No
IDoes the noise fade away when the vehicle har-ness is moved away from the radio chassis?
(if the harness is not in the proper position).
NoIf there is more noise than other radios, consult a service
center.
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A-4
Broadcasts can be heard but both AM and FM have a lot of noise.
(1)Noise occurs when the engine is stopped.
YesJ
(2)Noise occurs when the engine in running.
Do the following measures eliminate the noise?
@ Tune to a station with a strong signal.
l Extend the antenna completely. (Whip antenna)
l Adjust the sound quality to suppress high tones.
NoIs the radio body ground mounted securely?
Yes
Securely tighten the nuts for the bodyground.
Yes
YesClean the antenna plug and ground
wire mounting area. Mount the anten-
na securely. On a vehicle with a motor
antenna, check the antenna itself. (Re-fer to E-1, 2.)
If there is more noise than other radios, consult a servicecenter
NOTE
About noise encountered during FM reception only.
Due to differences in FM and AM systems, FM is
noise interference (first fading and multipath). (Refer
to A-2.)
not as susceptible as AM to interference from en-
gines, power lines, lightning, etc. On the other hand,
problem with the radio.>waves of noise or distortion generated by typical
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IA-7Some noise appears when there is vibration or shocks during traveling.
‘d ~
Are connectors properly connected?
YesNo
---+ Ensure proper connection
t
Does noise appear when the radio switch is turned on while theNovehicle is stopped and the radio is struck while tuned away fromLa station?
YesStatic electricity noise:
Body static electric from the shock absorber rubber bushings used
to prevent vibration, tires, etc. occurs because of separation fromthe ground, causing a buzzing noise.
Since no measures can be taken on the radio side, steps shouldbe taken to discharge the static electricitv of the vehicle bodv.
tIs the radio correctly grounded?
(Is the mounting screw tightened securely?)
1 Yes
tIs the antenna correctly grounded? (If noise appears when the Nocantenna is moved, this means the ground is not securely con-
nected.)
If rust is present on the antenna ground screw, clean and tightenthe ground securely.
Yes
1 Reoair or reolace radio.1
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A-8Noise sometimes appears on FM during traveling.
NoIs the antenna completely extended?
Yes
t Check the antenna itself.
(Refer to E-l, 2.)
+Does the problem clear up whenre
1 No
Yes
iDoes the problem appear only in certain locations and only with yes
certain stations?
No
~ Due to electrical field conditions. (Multipath
noise*, fading noise*).
Are connectors property connected?
Yes
Check connector connections.1
tDoes noise appear when the radio switch is turned on while the
vehicle is stopped
and the radio is struck while tuned away froma station?
Yes
No*Static electricity noise:Sody static electric from the shock absorberrubber bushings used to prevent vibration, tires,etc. occurs because of separation from the
ground, causing a buzzing noise.
Since no measures can be taken on the radioside, steps should be taken to discharge the
static
electricitv of the vehicle bodv.
Is the radio body correctly grounded?
No(Is the mounting screw tightened securely?
)
Yes
-) Tighten the screw securely.I
Is the antenna correctly grounded? (If noise appears when the antennais moved, this means the ground is not securely connected.)
Yes
If rust is present on the antenna ground screw,clean and tighten the ground securely.
*
1 Repair or replace radio.1
About multipath noise and fading noise
Because the frequency of FM waves is extreme-
ly high, it is highly susceptible to effects from
geological formations and buildings. These ef-
fects disrupt the broadcast signal and obstruct
‘reception in several ways.l Multipath noise
This describes the echo that occurs when the
broadcast signal is reflected by a large obstruc-
tion and enters the receiver with a slight time
delay relative to the direct signal (repetitious
buzzing).l Fading noise
This is a buzzing noise that occurs when the
broadcast beam is disrupted by obstructing ob-
jects and the signal strength fluctuates intricately
within a narrow range.
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There is noise but no reception for both AM and FM or no sound from AM, or no sound from FM.
Example: in an underground garage or
Is proper performance
hicle is moved?
tt
Is the antenna completely extended?
YesNo
Check the antenna itself.-W (Refer to E-l, 2.)
Does tuning solve the problem?
Yes
NO
tNoAre the antenna plug and radio unit properly connected?
Yes
- Reconnect1Does the problem disappear if connected to another radio?
No
Repair or replace radio.1t
Repair or replace the antenna.
(Refer to E-l, 2.)
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Is proper performance’obtained when the ve-pziT---wm
4tIs the antenna completely extended?
YesNoCheck the antenna itself.
(Refer to E-l, 2.)
t
NoYes
Is the problem limited to the reception of a specific radio station yes)Electrical field condition related*.from a specific position?(multipath noise or fading noise)
No
iIs the antenna plug properly connected to the unit?
Yes
Ensure proper connection.Does the problem disappear when a different radio is connected?Repair or replace radio.
Repair or replace the antenna.
(Refer to E-l, 2.)
*For multipath noise and fading noise prob-
lems, refer to P.64-167.
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B-7Too few automatic select stations.
tIs the antenna completely extended?
YesNo1Check theantennaitself.Is the antenna plug properly connected to the equipment?
Yes
Ensure proper connection.Does the equipment work properly if the radio is changed?
Repair or replace radio.
B-8lnsuff icient memory (preset stations are erased).Is multi-purpose fuse No. 19 blown or is the circuit open?
NoReplace fuse or repair harness.
Disconnect and check the connector at the rear of the radio. Is the memory
backup (battery) power beina supplied?Repair harness..-IYes
tRepair or replace radio.
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E. MOTOR ANTENNA
LE-lMotor antenna won’t extend or retract.
Clean and polish the surface of the antenna rod.Is the radio power switch ON?
Yes
Switch it ON.Is voltage (approx. 12 V) emitted to the radio’s motor antenna terminal’?
YesRepair or replace the radio.i
tIs the antenna bent?
No
tIs the antenna relay OK?
Yes
Replace the antenna relay.
iIs the motor OK?
YesNo
c
Repair the harness.I-
TSB Revision. Replace the motor.