A coaxial cable, commonly known as coax,  is utilized to transfer a signal from a radio or tv transmitter to an antenna. Such cable is made up of cords inside and an outer metal braid mesh separated by a foam-like insulation material known as the dielectric. Sometimes, a coax can become damaged where the dielectric gets broken or separated, permitting the internal wire to come into contact with the external braid. This will cause a short that can harm the transmitter. Cables should be tested for connectivity problems by executing conductivity tests with a multimeter.

If you notice that the transmitter is not working properly or if you are experiencing recurrent signal losses without any reason, then it is advised to test the Coax cable.

How to test a coaxial cable?

Here are some reliable steps and methods to test coax cable for loss of the signal:

Step 1

The first step to test a coax cable starts by disconnecting both ends of the coaxial cable from any device to which you have connected the cable.

Step 2

Coil the coax cable so both ends connectors can be reached with the metal probes of the tester, it will make it more comfortable to take reliable measurements through the multimeter.

Step 3

Place the test probe wire plugs into the tester, put the black negative wire plug into the multimeter’s “COM” jack and the red positive wire plug into the jack marked (+) on the tester.

Step 4

Activate the tester and rotate the measurement-type dial to calculate resistance or ohms. Set the dial option to ‘Continuity’ for taking the measurements. To check whether the continuity testing will work or not,  touch the metal probe tips together to create an electrical short. If the tone emits that indicates the instrument is working appropriately.

Step 5

Connect the black negative end of the multimeter to the center pin (if available) or center wire (if there´s no connector available) on one end of the coax cable, without allowing it to make contact with the outer layer of the connector or the braided wire on that end. The tip needs to be touching only the center wire of the cable or the center pin of the connector.

Step 6

Connect the red positive end of the multimeter probe to the center pin or wire on the other end of the coaxial cable, it is important that the metal tip is only making contact with the center and not touching any other metal. If a tone is emitted from the inner speaker of the testing instrument, this indicates that the center wire is not damaged along the length of the wire and that the center wire is in great condition.

Step 7

If you are using a coaxial connector, move the black negative metal probe from the center pin, or wire, and touch the outer jacket of the connector. If you are not using the connector to test the coaxial cable, then touch the with the negative probe with the braided outer wire of the coax. Maintain the tip of the positive end of the probe on the center wire of the other end. Check whether a tone is emitted from the tester.

The multimeter should not emit any sound, If a tone is heard, this means the insulation is damaged in the length of coaxial cable and that the coax should be replaced.

If you would like to receive a quote for any of Network Custom Cables, Audio or Video Vustom Assemblies, please do not hesitate to contact us by sending an email to [email protected] or calling in the USA this phone number (682-325-1944)

Jessica Cardona