How to Measure an Insertion Loss of a Coax Cable
- 1). Measure the signal strength available at the point at which you plan to connect your coaxial cable. You must make the signal strength measurement at a specific frequency such as 54 megahertz (MHz), 450 MHz or 1 GHz. This point may be a cable television splitter in your home or a signal distribution port on an amplifier in a commercial building.
- 2). Write down your measurement, which will look like "X" decibels at "XX" MHz.
- 3). Connect the piece of coaxial cable you plan to measure to the signal source you just measured. This connection is known as the input end of the selected piece of coaxial cable. The other end of this piece of coaxial cable will be called the output end.
- 4). Measure the output signal strength from the output end of the piece of coaxial cable using the same test equipment and calibration; take the measurement at the same frequency you used on the initial measurement.
- 5). Write down your measurement from Step 4, which will again look like "X" decibels at "XX" MHz.
- 6). Subtract your second measurement (output end) from your initial measurement (signal source) to determine the insertion loss of this particular piece of coaxial cable.
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