How to Feed to a Multiband Quad Antenna

How to Feed to a Multiband Quad Antenna

• 1

  Determine the total length of transmission line you will require to reach from your antenna to your radio operating position. Include sufficient additional length for attachment points and building entry. Cut two equal lengths of 12-gauge, stranded insulated copper wire in the length you have determined. Stretch these two wires out in a large open area for ease of assembly.

• 2

  Drill 1/8-in. holes 1/2 in. from each end of each of the five-in. cut pieces of 1/2-in. PVC pipe. Drill straight through the diameter of each end of each piece of pipe. These will serve as insulating spacers, which will keep the conducting wires 4 in. apart upon completion.

• 3

  Assemble the ladder line by sliding drilled PVC pipe sections onto the pair of wires through the drilled 1/8-in. holes. Work from both ends of the wires so that sliding spacers is no more than half of the wire length. Continue adding spacers every 5 or 6 in. along the entire length of transmission line.

• 4

  Once you have installed and evenly spaced all of the spacers along the fully stretched wires, add a dab of hot glue to each inside and outside contact point between the PVC spacers and the conductor wires. This amounts to 8 dabs of glue for each spacer and will keep the spacers from sliding or slipping out of place upon installation.

• 5

  Strip off 1.5 in. of insulation from each end of the two conductor wires. Connect one pair of wire ends to the antenna terminals and the pair at the lower end of the ladder line to the balanced line terminals of your trans-match antenna tuner.

• 6

  Tune your radio to your various operating frequencies and look for any nearby resonant sweet spots inherent in your antenna system. Tune to your other frequencies and tune for minimum SWR (standing wave ratio) as indicated by the crossed needle meter or twin meters on your tuner. Record your tuner settings for future reference and for rapid band switching.