Use a noise sniffer along with the vehicle radio in order to locate hot spots. Hot spots generate radio noise interference. Hot spots can be found in the following locations:
| • | In the harness |
| • | In the upper part of the dash |
| • | Between the hood and the windshield |
You can make the sniffer from an old piece of antenna lead-in. You can get an old piece of antenna lead-in from a mast or a power antenna. Use as long a piece of lead-in as is available.
When the sniffer is plugged into the radio's antenna socket, the 2 sections of the wire in which the black coating and braided shield are stripped back become the antenna. The sniffer can then be used to probe and search out hot spots.
Place the sniffer parallel to the wire in order to achieve the best results when you test for noise on a wire.
Perform the following steps in order to use the sniffer:
- Tune into the complaint noise.
- Disconnect the antenna.
- Plug the sniffer into the antenna socket.
- Turn the radio volume UP.
- Search for the noise source.
Keep your fingers off of the 2 probes.
Customer's Tips
FM Stereo
Select stations within range in order to achieve the best FM fidelity.
The best FM fidelity comes from stations within a 16-64 km (10-40 mile) range. Beyond the 16-64 km (10-40 mile) range, noise or flutter may appear. The noise may be due to the line of sight range limitations of FM signals.
Use one of the following methods in order to reduce the treble response in areas near the edge of the range:
| • | Reduce the treble. |
| • | In EQ radios, slowly slide down the 10K control. |
Tall buildings or hills may cause shadows or cancellations of FM signals. Shadows or cancellations of FM signals will sounds like a pop or a momentary hiss. Reduce the treble or the 10K setting in order to correct the condition.
Due to the advanced circuits in DELCO receivers, interference from other stations are rare. Interference occurs when stations are very close in frequency or certain geographical conditions are present. Correct interference by selecting another station or changing to a tape or CD.
AM Stereo
AM stereo does not have the flutter characteristics of FM stereo. However, any of the following items may cause interference:
| • | Powerlines |
| • | Neon signs |
| • | Atmospheric conditions |
| • | Unwanted stations |
Reduce the treble or tune into a stronger station in order to reduce noise.
