1998 Volvo S90
Sending signals
The FM waves do not follow
the earth's surface nor do they
bounce off the atmosphere. For
this reason their range is
limited. The AM waves follow
the earth's surface and reflect
against the atmosphere, giving
them a wide range.
Weak reception (fading)
Because of the limited range of
the FM senders and the fact that
these waves are very reflective,
this problem usually occurs
with FM reception. If the sender
is blocked by buildings or
mountains, static can result.
Static
The reason why FM but not AM
is audible is covered parking
areas, under bridges, etc, is that
FM signals reflect against solid
objects such as buildings.
Because these waves are very
reflective, static can result. This
static is the result of the reflected
signal and the direct signal
reaching your antenna at slightly
different times causing a
cancellation of all signals. This
problem occurs largely in built-
up areas. Your car is equipped
with a dual antenna system
which helps alleviate this
problem.
Audio systems, general information (cont.) pg. 163
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1998 Volvo S90
Cross modulation
If you listen to a weak station in
the vicinity of a stronger one,
both stations may be received
simultaneously. If the car is
moved a short distance, the
weaker signal may be heard
more clearly.
FM - reasons for distortion
FM is affected by the electrical
systems of nearby vehicles,
especially those without
suppression. The distortion
increases if the station is weak
or poorly set.
The FM reception is not as
sensitive to electrical
disturbances as AM.
AM - reasons for distortion
AM reception is sensitive to
electrical disturbances such as
power lines, lighting, etc.
Audio systems, general information (cont.) pg. 164
FM stereo reception
Stereo reception places very
high demands on the signal
quality which means the type of
distortions previously
mentioned become even more
obvious. The signal strength
needs to be stronger for good
stereo reception and this limits
the effective range of the
slender.
We hope that this information
proves to be useful and
Radio antenna (sedans)
NOTE: Always lower the
antenna when using an
automatic car wash or entering
a garage.
The antenna should be cleaned
at least every 10,000 miles
(16,000 km) or more frequently
if needed. Use WD40 for
cleaning.
Spray the antenna with WD40
and wipe it clean and dry with a Radio antenna (wagons)
The radio antennas (2) are built
into both side windows of the
cargo area. These antennas also
have factory installed antenna
boosters.
NOTE: The antennas will not
function without these boosters.
Place objects in the cargo area so
that the antenna wires on the
inside of the window will not be
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