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How to Troubleshoot a VHF Antenna

VHF antennas can consist of a mast and a boom. Some scanner-oriented antennas use a mast and three vertical radiators and three horizontal radials. Design is based on the reception and transmitting requirements, but they all need to be made from metals like steel and brass. Problems with a VHF antenna can be related to the installation, wiring and reception. These kinds of problems can be identified and corrected.

Things You'll Need

Guy wires
Anchor bolts
Guy wire rings
Upgraded cable
Crimper tool

Instructions

- 1
  Make sure that the mount used for the mast is suitable for the type of installation if the antenna moves in the wind. Use specific mounts for specific applications. Base and roof mounts lock into a U-bolt. Small antennas can mount to a vent pipe with a vent pipe mount. Specific wall mounts are used on the side of a structure.
- 2
  Check the mount by grasping the mast and trying to move it. Some limited sway is normal, but it shouldn't be more than an inch or so from vertical, and the mast should bounce back when you let go.
- 3
  Install guy wires if the movement is more than acceptable from your test in the previous step. Install guy wire anchor bolts, estimate the length of guy wires and cut them. Then attach the wire to the mast using guy wire ring. Use at least three guy wires.
- 4
  Check the wiring between the VHF antenna and equipment. The longer the cable length, the greater the signal loss. Consequently, longer runs need thicker cable with more metal in it to make up the loss. Try to reduce the length of cable if you experience loss, or upgrade the cable. Check that all of the connections are sound, and re-crimp the connectors if they appear loose.

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