Noise Problems

Audio System / NOISE PROBLEMS

A. Questionnaire for noise:





It is very important for noise troubleshooting to have good understanding of the claims from the customers, so that make the best use of following questionnaire and diagnose the problem accurately.

HINT: In the case that the noise occurrence condition does not meet any of the above questionnaire, check based on the "Trouble Phenomenon".

Refer to descriptions for multipath and fading.

B. Matters that require attention when checking:
* Noise coming into the radio usually has no harm for practical use as the noise protection is taken and it is hardly thinkable for an extremely loud noise to come in. When extremely loud noise comes into the radio, check if the grounding is normal where the antenna is installed.
* Check if all the regular noise prevention parts are properly installed and if there is any installation of non-authorized parts and non-authorized wiring.
* If you leave the radio under out of tune (not tuning), it is easy to diagnose the phenomenon as noise occurs frequently.





C. Antenna and noise:
Electronic signal received by the antenna will reach to the radio transmitting through the core wire of the coaxial cable. Any noise wave other than radio wave is mixed into this core wire, that naturally causes noise in the radio and poor sound quality. In order to prevent these noises from mixing into the radio, the core wire inside the coaxial cable is covered with a mesh wire called shield wire. This shield wire shelters the noise and transmits it to the ground, thus preventing noise from mixing in.
If this shield wire has grounding failure, that causes noise.





D. Choke coil and noise:
The choke coil is connected in the rear window defogger circuit. This is connected so to prevent noise from mixing into the radio by making the noise current included in the power source of the rear window defogger flow to the ground.








E. Antenna code continuity check and grounding point:

HINT: During troubleshooting, in case that the antenna code continuity check, grounding check and grounding check of the choke coil are needed, please check referring to the illustration.