![]() Inductance of lower loading coil (in wire 11) = 6 uH Because of the asymmetric ground load at the lower leg of the antenna, I fed the dipole silightly off center and reduced the inductance of the lower loading coil empirically.ĭistance lower capacity hat to source S = 2 mĭistance source S to top capacity hat = 2.3 m The distance between the capacity hats of 4.3 m was given by the 20m resonance. So I opened my EZNEC 5+ and started to model. Performance of 20m vertical dipole, note 1.5:1 SWR bandwidth of 460 kHz!Īs I mentioned before, my interest was mainly a vertical dipole for 40 m. (yellow arrow) prevents the bracket from slipping down. Lower capacity hat, tied to the fibreglass pole. The coax feeder has to be routed as far away from the lower part of the antenna as possible. Vertical dipole for 20m (no coils) and 40m (w. I chose the distance between the two capacity hats for a resonance at 20m without loading coils: Unfortunately at the time of writing the telescopic whips are no longer avalable at Radio Shack, but any whip could be used.Ĥ telescopic whips per capacity hat, total span 1.9m, mounted crosswise bottom to bottom onĪngle brackets of different sizes to fit the pole Many thanks to Steffen, DL6SFR, for sending me two more links to portable vertical dipoles (see bottom of page).Ī load of telescopic whips I bought at a Radio Shack Sale on a recent trip to the US, as well as a 6m / 0.6m fibreglass pole from Lambdahalbe awaited to be used in a project. My primary interest was a lightweight portable vertical antenna for 40m, as for 20m - 10m I use my C-Poles. VERTICAL DIPOLE FOR 40M (AND HIGHER) VERTICAL DIPOLE FOR 40M (AND HIGHER) LIGHTWEIGHT PORTABLE VERTICAL DIPOLE ON A FIBREGLASS FISHING POLEĪn advertisement for the i-Pole by Proantennas on the WIMO Homepage made me curious and I decided to give that antenna system a try too.
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