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How to Measure the RF Output of an Antenna

While your CB (Citizen Band) or scanner radio may be generating enough power to pickup nearby frequencies, a leaky coaxial cable or a poorly aligned antenna could still decrease the quality of your radio's broadcast and reception power. But with the help of an SWR/Power meter (SWR stands for standing wave ratio), you can find out how much power is being dispersed and how much of that power is being relayed by your antenna.

Instructions

- 1
  Disconnect your antenna's coax cable from the back of your scanner or CB radio. Plug the disconnected coax end into the "ANT" port on your SWR meter.
- 2
  Connect the SWR/Power meter to your radio using a coax cable.
- 3
  Reference your radio's output power specifications and then set the SWR/Power meter's wattage to in range. For example, if the radio is 4 watts, you would set the meter to the 10 watt range. But if the radio is 50 watts, you'd set it to the 100 watt range.
- 4
  Set the SWR/Power meter to the "FWD Pow" or "Forward Power" setting to find out how much power is sent to the antenna from the radio.
- 5
  Set the SWR/Power meter to the "REF POW" or "Reflected Power" position to see how much power is lost through the antenna.
- 6
  Subtract the amount of reflected, or lost, power from the amount of forward power to find out how much power your antenna is transmitting.

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