Topband: More on loop antennas

[Earl W Cunningham]

In my haste to model N6TR's proposed half loop, I made two errors. 
First, I modeled using zero conductor resistance.  Second, I used the
incorrect gain reference.

After changing the conductor resistance in the model to use copper, and
correcting the gain reference (1.25 dBi for a 1/4-wave vertical made of
#14 AWG copper wire over "average" soil), here are the figures for the
half loop with 50-foot vertical sections and a 179-foot horizontal
section, fed at the base of one of the vertical sections (at 1830 kHz):

Feedpoint impedance = 32.3 + j0 ohms
Gain = 2.06 dB above a single 1/4-wave vertical

If the vertical sections of the antenna can be made 62' (the horizontal
portion becomes 156' for resonance at 1830 kHz), then we have the
following:

Feedpoint impedance = 50 + j0 ohms (bingo)
Gain = 1.66 dB above the 1/4-wave vertical

#14 AWG wire was used for the entire antenna in the models.

73, de Earl, K6SE



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