Looks like Dan is building a copy, his site has some interesting babble going on about it.
. . . approximates a half wavelength at the operating frequency or frequencies in question and only when any conducting support structure is insulated or isolated from the "mast" section.
Interesting take on this. Perhaps someone will compare it to other 3/4ƛ antennas.the matching section aside, two thirds of the antenna wasn't in the box when you bought it. element 14 is the 1/2 wl. end of the dipole (below level A) and above level A is the other 1/4 wl. element forming the extended 3/4 wl. dipole, top loaded or not.
Interesting take on this. Perhaps someone will compare it to other 3/4ƛ antennas.