Thursday, February 17, 2011

Portable 3 element 2M beam antenna



In April 1993 QST, Nathan Loucks, WB0CMT, described the 2-m beam shown in Fig. The boom and mast are made from 3/4-inch PVC plumber’s pipe. The three pieces of PVC pipe are held together with a PVC T joint and secured by screws. Elements can be made from brass brazing or hobby rods. (If you can’t find a 40-inch rod for the reflector, you can solder wire extensions to obtain the full length.)

Drill holes that provide a snug fit to the elements approximately 1/4 inch or so from the boom ends. Epoxy the director and reflector in place after entering them in these holes. A pair of holes spaced 1/4 inch and centered 16 inches from the reflector hold the two-piece driven element. The short ends of

the element halves should extend about 1/4 inch through the boom. Solder the 50-Ù feed line to the driven element as shown in Fig

Loucks used a pair of 4-inch pieces held in place by #12 or #14 jam screws (electrical connectors) toextend and adjust the driven element to allow for operation in various parts of the 2-m band. You can trim the driven element to length for operation in the desired portion of the band if you prefer. The figures show the beam assembled for vertical polarization. You may want to turn the boom pieces 90° for horizontal polarization for SSB or CW operation.

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