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.

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.

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. To help minimize this situation, turn down the treble.

Cross modulation

If you listen to a weak station in the vicinity of a stronger one, both stations may be received simultaneously.

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 reception is sensitive to electrical disturbances such as power lines, lighting, etc.

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 sender.

We hope that this information proves to be useful and provides you with a better understanding of the problems related to car radio reception.

Reception conditions are not always optimum and this is, of course, beyond our control. However, we have endeavored to make the Volvo Audio System of a quality that will enable you to enjoy the best possible reception no matter what the reception conditions may be.

Radio antenna (sedans)

Spray the antenna with WD40 and wipe it clean and dry with a rag. Spray it again. Lower and raise the antenna. Wipe it clean and dry again. Lower and raise the antenna 4-6 times. Make sure it is dry and free from dirt or lubricating oil.

Radio antenna (wagons)

The radio antenna is built into the driver side window of the cargo area. This antenna also has a factory installed antenna booster.

Place objects in the cargo area so that the antenna wires on the inside of the window will not be damaged. When cleaning the window be careful that the wires are not scratched by rings, etc. If they are damaged, radio reception will be impaired.

Cassettes

Take up slack using a pen or a pencil before inserting a cassette in the cassette slot.

Cassette cleaning

We recommend the use of the Volvo Cleaning Cassette available as a genuine Volvo accessory. Regular use improves sound quality, cleans vital parts and prevents tape tangle.

pg. 1:33 Technical specifications

Technical specifications

Output: 4 x 20 W (10% dist.)
Output impedance: 4 Ohms
System voltage: 12 Volts, negative ground

Radio

System: superheterodyne system with HF-step. Electronic suppression device

Frequency range:
SC - 810 87.9 - 107.9 MHz
530 - 1710 kHz
Sensitivity: FM 1.1 V
AM 20 V
Stereo separation: 35 dB

Cassette deck 4 - track, 2 channel stereo

Tape speed: 4.76 cm/sec.
Channel separation 48 dB
Frequency range 30 - 15000 Hz
S/N (120 V) 55 dB
S/N (70 V) 55 dB
Wow and Flutter 0.13%

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