Mast Antennas
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Unplug antenna lead-in connector from radio receiver and plug a test antenna into radio. Make sure antenna base is grounded to the vehicle chassis and keep hands off the mast.
Check radio reception in an area away from electrical interferences. Tune to several weak and strong AM and FM stations. If the radio reception improved, the problem exists with the antenna and/or lead-in cable. If the reception is still poor, refer to Audio System Troubleshooting Hints .
Important: Always zero out the DMM before taking a resistance measurement in order to ensure an accurate reading.
Measuring Resistance (Mast Antenna System)
| Ohmmeter Probes At Points | Resistance Measured In Ohms |
|---|---|
| 1 and 3 | Less than 0.2 |
| 1 and 4 | Less than 0.2 |
| 1 and 6 | Less than 0.2 |
| 1 and 2 | Infinite |
| 1 and 5 | Infinite |
| 1 and 7 | Infinite |
| 2 and 3 | Infinite |
| 2 and 4 | Infinite |
| 2 and 6 | Infinite |
| 3 and 4 | Less than 0.2 |
| 3 and 6 | Less than 0.2 |
| 3 and 5 | Infinite |
| 3 and 7 | Infinite |
Refer to the table when testing the antenna and/or lead-in cable.
- Measure the resistance from the coax center conductor to antenna mast. Ohmmeter probes at points 2 and 7.
- Total resistance from end to end of center conductor (Ohmmeter probes at points 2 and 5):
- RG-58/RG-59 type cable - less than 0.20 Ω
- RG-62/RG-62M type cable - less than 3.5 Ω
- When checking the resistance, cautiously wiggle the lead-in tip and cable. Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS .
- Replace the antenna and/or lead-in cable when the above readings are not obtained. Refer to Fixed Antenna Mast Replacement for service procedure.