Inspection Procedure 20
INSPECTION PROCEDURE 20: Distortion on FM OnlyDIAGNOSIS
STEP 1 Check that the distortion is present when the radio is tuned to another station
Q: Does the distortion persist when the radio is tuned to another station?
YES: Go to Step 2
NO: The signal from that station is too weak
STEP 2 Relocate the reception area and check the radio
Q: When relocating the reception area does the distortion increase or decrease?
YES: The cause may be multipath or fading noise Multipath noise is the echo that occurs when the broadcast signal is reflected by a large obstruction and enters the receiver with a slight time delay relative to the direct signal (repetitious buzzing) A fading or buzzing noise may occur when the broadcast beam is disrupted by obstructing objects and the signal strength fluctuates within a narrow range
NO: Replace the radio and CD player or radio, CD player and CD changer Check that a distortion is resolved