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How to Make a Homebrew Mobile VHF Antenna

If you are an amateur radio enthusiast with a hand-held VHF radio, a homemade mobile antenna can improve your signal range. Many areas of the country have access to VHF repeater stations that allow long-distance broadcasting. This accessibility is appealing to both veteran and novice hams alike, which has promoted widespread use of this radio band. A portable VHF antenna will attach to your hand-held radio's antenna jack, and boost your signal range in the field.

Things You'll Need

Wood dowel, 1/2-inch diameter, 2 inches long
Electrical wire, 20-gauge, 10 feet long
Twin-lead cable, 300-ohm, 20 inches long
Coaxial cable, 50-ohm with connectors, 10 feet long
Ring terminal lug, 20-gauge
Power drill and 1/8-inch bit
Soldering iron and solder
Electrical tape
Wire-stripping tool
Utility knife
Tape measure

Instructions

- 1
  Drill a 1/8-inch hole through the dowel, 1/2 inch from the end. Thread 38 5/8 inches of electrical wire through the hole. Wrap the remaining wire tightly around the dowel 13 times. Drill a 1/8-inch hole through the dowel after the 13th turn, and thread the remaining wire through the dowel. Cut the wire to 38 5/8 inches at this end as well. Wrap the dowel with electrical tape to secure the wire in place.
- 2
  Remove 1/2 inch of insulation from one end of the twin-lead cable. Twist the wire pair together, and secure the connection with solder. This will be the bottom of the antenna.
- 3
  Measure 1 1/2 inches from the solder point. Carefully remove 1/4 inch of insulation from both twin-lead wires. This will be the connection point for the feed line.
- 4
  Measure 16 11/16 inches from the solder point, and cut the twin-lead cable to this length. Remove 1/2 inch of insulation from the left wire at the end of the cable. Cut the right wire out, leaving the left wire extending 1/2 inch from the end of the cable.
- 5
  Strip 1/2 inch of insulation from one end of the electrical wire. Solder this end to the left wire at the end of the twin-lead cable. Wrap electrical tape around the connection to protect the solder joint.
- 6
  Cut the connector from one end of the coaxial cable. Remove 1 inch of insulation from the cable. Slice down the side of the braided sheath, and twist the braid into a wire. Remove 1/4 inch of plastic insulation from the inner copper wire.
- 7
  Solder the coaxial copper wire to the left wire of the exposed twin-lead. Solder the twisted braid to the right wire. Protect these joints with electrical tape.
- 8
  Crimp the ring terminal to the free end of the dowel wire. Hang the antenna from the ring terminal.
- 9
  Connect the free end of the coaxial cable to the external antenna jack of your VHF radio.

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