This e-mail contains the YO file for the 5 element 20M Yagi on a 48 foot
boom at W3LPL. Five of these antennas have been in use for the last
several years at 50, 100 and 200 feet; operated individually and in
stacked pairs.
This design provides an excellent compromise between gain, front/back
ratio and VSWR across the entire band while avoiding a low feedpoint
impedance often found in other designs.
73
Frank
W3LPL
donovanf@sgate.com
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W3LPL 5 Element 20M Yagi 48 Ft Boom (as built)
Height 2340.000
14.000 14.200 14.350 MHz
5 elements, inches
1.2500 1.1250 1.0000 0.8750 0.7500
0.0000 33.7500 50.2500 33.0000 33.0000 67.0000
86.0000 33.7500 50.2500 33.0000 33.0000 52.0000
171.0000 22.0000 47.8750 33.0000 33.0000 64.0000
349.0000 22.0000 31.2500 33.0000 33.0000 77.0000
570.0000 22.0000 43.7500 33.0000 33.0000 52.0000
Use the M and Tab keys to enter the following
T-match parameters:
Rod diameter: 0.5"
Rod Spacing: 6"
Rod Length: 48"
Lead Length: 3"
Series Cap: 99999 pf
Feed Z 200 ohms
Experience indicates that the driven element
tip must be lengthened to 62 inches, the
length that produces a modelled impedance of
+j20 ohms at 14.200 MHz
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