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How to Connect an Antenna to a Spectrum Analyzer

A spectrum analyzer is a useful electronic device that displays a graph of signal strength versus frequency. The analyzer̵7;s display reveals the presence of local radio signals, electrical noise and other phenomena, and is useful for testing all types of radio equipment. To pick up radio signals, most spectrum analyzers require a separate external antenna suited for the radio frequencies in which you are interested. In addition, the antenna may need a pre-amplifier to strengthen the signal. Proper cabling is also required between the antenna, pre-amplifier and spectrum analyzer.

Things You'll Need

Pre-amplifier
2 radio frequency cables

Instructions

- 1
  Position the antenna so it picks up the maximum amount of radio signal. Certain types of antennas are more directional than others, so they work best when they are aimed in the direction of the broadcast signal.
- 2
  Connect the antenna to one RF cable. For example, a BNC cable will have a female part that fits over the male part on the antenna by lining up the bayonet parts on each connector, pushing in with moderate force and twisting 90 degrees clockwise. For an RG-59 type connector, slip the inner wire of the cable into the female connector on the antenna, then screw the outer part on clockwise until it fits snugly.
- 3
  Connect the remaining end of the RF cable to the pre-amplifier input.
- 4
  Select the second RF cable and connect one end to the pre-amplifier̵7;s output. Connect the remaining end to the spectrum analyzer̵7;s input.
- 5
  Turn the power on to the pre-amplifier and spectrum analyzer. Allow sufficient time for the spectrum analyzer to perform its automatic start-up calibration.
- 6
  Adjust the pre-amplifier̵7;s gain so the spectrum analyzer is receiving a sufficiently, but not excessively, strong signal. If the signal appears weak on the analyzer, increase the gain. You can also adjust the signal on the analyzer itself, if necessary.

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