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.

Tips & Warnings

    Weatherproof the antenna by fitting it inside a length of PVC tube and capping the tube at both ends. Drill holes for the cable, and seal the holes and caps with silicone sealant. Hang the tube using an eye bolt fitted to the upper cap.

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