Amature Radio Trader MARCH 1998

Emergency antennas are extremely valuable when you need them. You don’t need to suffer an earthquake or storm damage to make use of an “emergency” antenna. You may simply be in a hotel room on vacation or inside a building helping to test your cities disaster preparedness system. Whatever the reason, a handy antenna can really save the day.

Once again we will work with the 2 meter band (144-148 MHz). This is the most popular band around the country. This J-POLE antenna can be modified to operate with any band by changing the length of the elements. It is called a J-Pole because the wiring looks like a “J’.

This emergency antenna is constructed out of 300 ohm TV antenna twin lead. You old timers will remember this type of antenna wire. Every home in America used this type of wire to connect its TV set to the antenna on the roof. Remember the rabbit ear antenna that would sit on top of the TV? It also used 300 Ohm twin lead.

Use an old piece of twin lead that you may have around the house or run over to your  local     

hardware store and pick up 6 feet. Use a pair of wire cutters or scissors and remove the insulation as shown. You only need to cut wire in one place. BE CAREFUL and only remove the insulation from the points where the coax connects to the twin lead.

After you have the insulation removed, twist the two sides of the twin leads together as shown (at the bottom of the antenna). Place some solder at the connection to insure full

contact. Connect the coax to the twin lead as shown. It should be connected 1 & 1/4’ from the bottom. Use solder at these points also. You may tape the coax to the twin lead to prevent stress on the solder points. Tape will also help prevent the wires from rusting.

Cut the twin lead to exactly 54 from top to bottom. Make sure you have cut the ground side notch 15 & 1/4’ from the ground connection point. Place a loop of plastic or other non-conducting rope at the top of the antenna to hang from the ceiling. This antenna will have a gain of at least 3 db.