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How to Measure an Antenna's Signal With a Multimeter

by James T WoodUpdated August 23, 2017
Polka Dot Images/Polka Dot/Getty Images

An antenna receives radio signals by generating a small electrical impulse that is transmitted down a conductive wire to the device. You can use an electrical multimeter to test whether a signal is traveling successfully down an antenna and to the receiving device. Any short in this electrical circuit will cause the signal to be disrupted. In addition, if the antenna isn't properly grounded, the signal will receive interference from the electrical potential of the antenna itself. The resistance of the antenna circuit is measured using the “Ohms” setting on a multimeter.

Set the multimeter to measure ohms, which is represented by the "Ω" symbol.

Remove the antenna cable from the receiving device. For example, if you are testing the signal on your car's antenna, unplug the antenna cable from the back of the radio.

Touch one lead of the multimeter to the metal part of the antenna and touch the other lead to the metal core of the cable. The ohms reading should be zero. If the resistance is greater than that, the antenna or cable is damaged, which is preventing a signal from reaching the reception device.

Touch one lead of the multimeter to the metal jacket around the antenna cable connector. Touch the other end to a grounded object. If you are testing a car, for example, touch a metal part of the car's frame. The reading should, again be zero; otherwise, the antenna is not grounded.

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