Shorty Forty Antenna

City dwellers and other flat dwellers know the practical difficulties they encounter when they try to put up an antenna for 40 meters. Finding space enough to accommodate 67 feet of wire is a real problem for them and most of them have to be satisfied by the inverted V. Whatever the book say, in practice the inverted V does not come up to the standard of a dipole antenna.

The Shorty Forty Antenna can be put up in the space required for a 20 meter dipole. If is a compact 40 meter dipole for limited space application by Jact Sobel W5VM. It is a center loaded antenna with a loading coil at the center. The two arms are 18 feet 6 inches long connected to the two ends of an inductor at the middle. The inductor consists of 30 turns of 12 SWG enamelled copper wire wound on 2.5 inch diameter PVC tube 5 inches long. There is six turns per inch so 30 turns will require 5 inches long. The shield of 50 ohms coaxial cable is connected to the center of the coil. The center conductor is connected to 2 or 3 turns away from the center, to a point which gives the lowest SWR. Compare this to a 67 feet dipole the saving in space is substantial.