[Antennas] End-fed half-wave religion

[Dan Richardson]

At 03:06 PM 7/14/2002 -0500, Jim wrote:
>Danny--
>
>[snip]
>
>As far as I've been able to gather, there exist quite a few antenna
>designs which are based on some sort of end-fed half-wave element,
>and a feeding/matching mechanism which involves the "other" side
>of the feed mechanism being connected to "nothing."  I gather
>these antennas (J-Pole, just to cite one common example) work not
>merely adequately, but downright impressively, at least in the
>clear.  I also gather there are some losses (though not the huge,
>dramatic losses other antenna systems would suffer) operating
>these end-fed half-waves with one end on or near the ground,
>without providing radials to improve the ground's ability to
>reflect the signal.  But the evidence seems to suggest that there
>are schemes for feeding/matching end-fed half-wave antennas which
>involve connecting the "other" side of the feedline to "nothing",
>and, notwithstanding arguments that such is impossible, do a fine
>job anyway.

Jim,

Lets get one straight. A j-pole does work. In fact, properly made its=20
performance is very close (a little better one way and a little less in=20
another) to a =BD-wave dipole. There is a complete path for loop current.

With that said can you now take a look at the "whole system" and see why it=
=20
works?

(Hint: consider George's comment regarding displacement current)

73
Danny