Modification of the KLM 7LP antenna to a six element yagi by Mike - K6MYC: Boom spacing from reflector end of boom: 0.000 44.375 108.625 197.000 289.000 360.000 1/2-inch diameter elements (Half Length): REF = 55.875 DE =51.25 (start long and trim to tune) DR1 = 50/813 DR2 = 49.750 DR3 = 49.625 DR4 = 50.062 Hairpin and balun attach to the DE. Hairpin phasing line is 20-inch long by 1/2 inch wide aluminum strap with holes drilled every 1/2 inch for about 4-inches from each end of strap. At 4-1/2 inch from end of strap twist strap 90 degree so strap can be bent into U-shape. Use holes to adjust length of strap for tuning (roughly 3-inch wide by 5.5 inch long). Antenna dimentions are for 50.175 MHz with SWR 1.05:1. SWR at 50-MHz is about 1.35:1 and 1.69:1 at 50.400 MHz. Mike estimates gain at 13.09 dB and F/B = 21 dB.
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