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How to Use an Ohms Meter When Checking Receivers

An ohmmeter is used to check the circuits in a receiver. The function of the receiver on a radio is to mix the incoming radio signal with the oscillator output so that the incoming signal is changed to an intermediate frequency that can be amplified and then easily heard. Signals come on different wavelengths. The ability of the receiver to pick up the desired signal versus other signals relates to the receiver selectability and sensitivity. The ohmmeter checks electrical continuity. If there is a large resistance, then there is a problem with that specific component, which makes the receiver faulty.

Things You'll Need

Ohmmeter

Instructions

- 1
  Disconnect the receiver from the main power line. This might be as simple as unplugging the receiver or turning off the circuit breaker that controls power to the receiver. Do not troubleshoot the receiver with the power on because this can damage the operator as well as the receiver.
- 2
  Test the receiver switch with an ohmmeter. If you cannot easily access the switch, disassemble the receiver so that you have access. Removing one panel often is enough to gain access.
- 3
  Set the ohmmeter to a low resistance. Place one of the ohmmeter leads on one side of the switch and place the second lead onto the other side of the switch. If the ohmmeter reads zero, there is no problem with the switch because the electricity is easily flowing through the switch. Increase the resistance on the ohmmeter to one that is normally used with the receiver. If the ohmmeter still reads zero, the switch is not the problem. If the machine does not read zero, there is a problem with the switch, and it needs to be replaced.
- 4
  Use the ohmmeter the same way as in Step 4 to check the receiver fuse, filter coil, thermistor and power-supply diode. If a resistance is read on any of the circuit parts, replace that part and recheck with an ohmmeter.

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