Detection of Noise Sources 2-5
3.0 Detection of Noise Sources
3.1 Noise Detection Procedure
Detection of offending noise sources is the heart of noise suppression because, after the noise
source is identified, the solution becomes obvious. A logical methodical procedure is basic to the
effective noise suppression.
Use your available equipment to best advantage. A pick-up loop, about one inch in diameter, can be
connected to a portable CB radio or a mobile radio being operated at a frequency similar to the
installed radio frequency but from an isolated supply voltage. The pick-up loop can be moved
throughout the vehicle with the radio used as a radiated noise detector. Be sure the pick-up loop has
sufficient insulation to prevent the input of the radio from coming into direct contact with high voltage
points in the vehicle ignition system.
A non-polarized bypass capacitor, which has alligator clips firmly attached, can be used on a trial-
and-error basis to locate wiring which needs additional filtering. Keep capacitor lead lengths short
for best suppression. Ceramic disc capacitors are not as suitable or effective as automotive coaxial
capacitors. (See Figure 2-3 TLN8845_ Noise Reduction Kit for Alternator-Equipped Vehicles and
Figure 2-4 TLN6252_ Noise Reduction Kit for Generator-Equipped Vehicles for part numbers.)
Figure 2-3 TLN8845_ Noise Reduction Kit for Alternator-Equipped Vehicles
Ignition
Switch
Battery
Ignition
Coil
Distributor
Breaker
Points
Resistive Wire
(Note 2)
Resistor
Spark Plugs
(Note 2)
Notes:
1. Noise reduction can only be achieved if components are grounded properly.
2. Items not supplied in kit. See auto parts dealer.
1
2
3
FL0830262-O
Reference Quantity Motorola Description
Number Part Number
1 1 0100839913 Lead & Lug Assembly
2 1 0882571B02 Capacitor, Coaxial (0.1µF, 100V)
3 1 3000502396 Ignition Coil Suppressor Cable
- 1 0180782A52 Hood Wipers (2) and Mounting
Hardware Kit (not illustrated).
FL0830262-O
To Next Page
Loading...
Need help?
General
