End/Base-Fed Inverted-L, 45 ft version, Elevation and Azimuth Radiation Plots

Below are presented the results of EZNec modeling of a 45 ft long End/Base-Fed Inverted-L, 23 ft high and 22 ft across.  Elevation patterns and Azimuth patterns at the peak of low angle radiation are plotted for all ham bands 80 Meters through 6 Meters.

For modeling purposes, a multi-connection distributed grounded counterpoise is used. This empirical structure provides a reasonable broadband counterpoise over the frequency range of interest.

inv_l-model-pic

Continue reading End/Base-Fed Inverted-L, 45 ft version, Elevation and Azimuth Radiation Plots

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End/Base-Fed Inverted-L, 90 ft version, Elevation and Azimuth Radiation Plots

Below are presented the results of EZNec modeling of a 90 ft long End/Base-Fed Inverted-L, 45 ft high and 45 ft across. Elevation patterns and Azimuth patterns at the peak of low angle radiation are plotted for all ham bands 160 Meters through 6 Meters.

For modeling purposes, a multi-connection distributed grounded counterpoise is used. This empirical structure provides a reasonable broadband counterpoise over the frequency range of interest.

inv_l-model-pic Continue reading End/Base-Fed Inverted-L, 90 ft version, Elevation and Azimuth Radiation Plots

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Classic G3TXQ Balun / Choke Article

Excellent technical reference article by Steve G3TXQ:

choke_impedances_g3txq

Amateur Radio (G3TXQ) – Common-mode chokes

The above chart presents the results of impedance measurements made on a variety of common-mode choke implementations across the frequency range 1MHz to 30MHz. Amateur frequency allocations are indicated approximately by the vertical grey bands. Continue reading Classic G3TXQ Balun / Choke Article

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Non-Resonant 25 ft Vertical with Metal Fence Counterpoise – 7 Bands

With the interest in 43 foot untuned verticals, and some of the less than accurate claims being made, I thought I’d share the results of a 25 foot untuned vertical antenna I developed a few years ago. Hopefully, I can shed some more light on its practical use, as well as show how to gain a bit more performance.

Continue reading Non-Resonant 25 ft Vertical with Metal Fence Counterpoise – 7 Bands

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