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CENTER-FED MONOBAND INVERTED LONG WIRE VEE 90 180 Degrees ______________________ 0 Degrees 270  A practical 20 meter basic design, assuming a 25 to 45 foot mast is used can be determined by the formulas below: (As always, it is wise to cut lengths long and trim as needed for best resonance) Leg length = 738 divided by frequency in mhz Leg length each half = 738/14.2 = 52 feet Line length = 650 divided by frequency in mhz Line length = 650/14.2 = 45 feet 9 inches. The "magic" numbers (738 and 650) in the formulas above appear to be arrived at by trial and error by Ed Noll and were presented in a chart in the book. To arrive at the "magic" numbers (constants) for each formula for different leg lengths and feeder lengths as determined by your particular lot size, just do the following: For longer leg lengths add 492 to each odd multiple of a 1/4 wave length: Example: 3/4 length = 738/freq 5/4 length = 1230/freq 7/4 length = 1722/freq and so on For longer feed line lengths, (REMEMBER THAT FEED LINE LENGTH MUST BE AN INTEGRAL MULTIPLE OF A HALF WAVE LENGTH TAKING THE VELOCITY FACTOR OF THE LINE INTO CONSIDERATION!) Example: 1/2 2/2 3/2 4/2 etc VF .66 LINE VF .81 LINE 1/2 325/F 400/F 2/2 650/F 800/F 3/2 975/F 1200/F Notice that that for .66vf line, 325 is added each time and for .81 line, 400 is added each time for the constants. (There were no other constants for other velocity factors in the articles in the book, however, you can still use the formula....Line length in feet (1/2 wave) = 492 X VF / freqmhz for determining the electrical half wavelength of a line) *********** Higher gain figures can be accomplished by bending the legs forward toward the receiving station. See the 3 Halfwave Vee Beam based on these same principles by Ed Nolls, W3FQJ. Editor's note: If you can find a copy of Ed's "73 Dipole and Long-Wire Antennas", by all means, get it. Ed also wrote many other books related to radio. Many are out of print but still can be found. You will have many hours of fun building and experimenting with Ed's designs which are a culmination of his many years of very talented dedication to Amateur Radio......N4UJW
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