Vertical Half-Rhombic

The vertical half-rhombic antenna is used as a field expedient antenna. It is effective at lower frequencies, however it's peak performance comes at higher frequencies.
To construct a vertical half-rhombic you will need the following:

  • 200 feet of WD-1/TT or WD-1A/TT
  • Electrical Tape
  • 400-600 ohms terminating resistor
  • Insulators or material to construct field expedient insulators
  • Radio set
  • Knife
  • Suspension line
  • Measuring device
  • Compass
  • Signal Operating Instructions (SOI) with frequency and call signs
  • Large open area

To erect the antenna follow these steps:

  • Determine azimuth from the transmitting radio to the receiving radio.
  • Measure 100 feet of wire.
  • Bend the wire in half to find the apex point for the connection of the insulator.
  • Connect insulator at the apex point and at both ends of the wire.
  • Tie a halyard to the insulator at the apex point. the suspend the apex between 20 and 30 feet above the ground.

  • (This can be achieved using a tree, camouflage poles, or whatever is handy)
  • Separate the two ends of the wire, ensuring that you keep them on line with the desired transmission azimuth.
  • Connect a wire to the ground side of the insulators at both ends of the wire, and stake them down to the ground.
  • Install a counterpoise.
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    • Run a wire from the ground side of the insulators at the ends of the antenna wire.

    • (Ensure that the counterpoise wire is directly under the antenna and one foot off the ground.)
    • Attach another piece of wire from the near end ground stake to a screw on the radio set case.

    • (For a uni-directional antenna attach a 600 ohm, 1 or 2 watt resistor across the far end insulator. for a bi-directional antenna leave the resistor off.)
  • Split the WD-1 at the near end, attach one piece to the bottom end of a whip antenna and screw it into the antenna connector on the RT. Connect the piece to a screw on the RT case for a ground.