After publishing Lecture No. 10 (Appendix) in these Web pages and duly informing Dave Gieskieng, Dave, not being on-line on the Web, made arrangements with a neighbour to send me the occasional communication by E-Mail. It was then on June 3 1998 that Dave sent me a message requesting that I add some additional information to my Lecture concerning the antenna canyon experiments, which Dave kindly supplied.
In his first paragraph, Dave expressed his concern that the antenna configuration that he had tested on so many occasions and in different sizes had been termed the 'Gieskieng Antenna' in Lecture No. 10 (Appendix). He suggested that the antenna should be termed the 'Maxwell Antenna' his reason being that, though it was a thoughtful and appreciated gesture on my part to designate the antenna by a name that is "that of the inventor", he felt "it should be named "Maxwell Antenna", since it only radiates a wave of l ohm impedance by containing the extraneous excessive electric fields generated by conventional dipole antennas, meeting Maxwell's prediction of radio waves having equal electric and magnetic components."
Now here I have a problem, because my use of the term was really intended to identify the kind of antenna that Dave Gieskieng had spent so much time and effort in testing. I did, in a sense, attribute the notion of 'invention' to the antenna, with Dave as the 'inventor' deserving recognition for the merit of his discoveries, but, my career background being in the patent profession, I would not seek to declare the antenna in question as an 'invention' in its own right.
Although this may seem to wander off the subject, I will indulge in a little clarification. As to the antenna itself, it has the simple diagrammatic form illustrated below.
A conventional dipole antenna actually radiates a compound wave consisting of a Maxwellian electromagnetic 1 ohm wave from the center portion and extra electric field from the outer portions. The latter goes away in lockstep with the former, but being in excess is frittered away with distance, being dissipated in a distance of 15 miles. This loss amounts to 3 db, or 50% of the antenna power input. It also has led to some misunderstanding of the "propagation medium" through which radio waves travel, since conventional field strength measurements are subject to these temporary high electric results and misjudgments of the impedance of free space, which has been given as 377 ohms, presumably an average, but a very long way from 1 ohm.
Electric field excited fluorescent bulbs held near the Maxwell antenna show containment of these excessive electric fields, and a very narrow null between the legs through to the shorting bar. The field about each leg is cylindrical to within a distance from the bar of about half the length of the bar, where it begins to taper off to the precipitous center null. It is as if being not able to radiate it is backed up all the way to the middle of the shorting bar and the electric field null there. A conventional dipole antenna in comparison has little electric field in the middle, since it is disposed of by radiation. The beginning of the electric field tapering mentioned may indicate where the Maxwellian radiating portion abuts the electric field containment portion. A curve from a previous paper indicates that the 1 ohm feed point is only 0.2 cm from the face of the shorting bar, or for all practical purposes at the joint between the bar and the line.
The data for the various values of impedance test power, as need to construct the curve, were obtained from a 50 ohm feed line and small toroidal transformers, and is straight line when plotted semilog, impedance vs. distance to the shorting bar.
The curve data is from a two meter, 4", spaced, ½" dia. copper pipe Maxwell with the cable sheath connected to the center of the shorting bar, and the inner conductor/transformer connection moved to achieve 1:1 swr. It is interesting that the curve yields approximate feed points to two, 20 meter Maxwell antennas constructed of ¾" copper pipe, with spacing of 3 ft. and 4 ft. 3 in.. A variety of 2 meter Maxwell antennas with different conductor diameters and spacing have been made with the same tested efficiency, so it would seem that the fields about the antenna have adaptive compatibility. It appears that both halves of the Maxwell antenna are operating in mutual imaging, and that the feed can be made directly from a cable to one side, or through a balun to both sides. It is important in either case that the cable leaves the shorting bar area as perpendicularly as possible to help preserve functional symmetry, by minimizing induction from the intense shorting bar field.
Fig. 4 as amended to link the asterisk Yagi points.
Attention is called to original Internet Fig. 4, (now amended in LECTURE NO. 10: APPENDIX) where a curve should have been sketched through the six asterisk Yagi points, to compare with the two Maxwell curves in vertical and horizontal modes. Otherwise, much of the Yagi representation is lost, and the bare points tend to mask the Maxwell trends. It will be noted that at height the favored direction Yagis are about 1 db less than either of the omnidirectional Maxwell curves with the no indication that lobe improvement with height would make a difference. At lower heights the Maxwell advantage is much larger. At an average distance of 20 miles to Squaw Mountain, the Yagi waves have been stripped of their extra electric field and are down to Maxwellian impedance. By containing that otherwise wasted field in the transmitting Maxwell antenna is most of what puts it ahead, even though it is omnidirectional.
The Maxwell antenna is also a better receiving antenna, since pulse noise travels down both the transmission line legs and cancels itself in the shorting bar area, whereas the outstretched arms of a conventional dipole gather in both noise and signal with equal dexterity of microvolts per meter of length. The shorting bar length is a fraction of the transmission line length. Also, having a spherical pattern it is less subject to fading due to changing of polarity of the signal, or its incoming angle. In the 26 world wide contacts comparing Yagi and Quad to Maxwell, the Maxwell never had to ask for repeats, whereas the others did.
The foregoing may be upsetting to those steeped in conventional antenna technology, but it offers an area for further exploration. A brief test using two Maxwells in Beam configuration rendered surprising gain and sharpness.
D. H. Gieskieng, WOFK
9653 Rensselaer Dr.
Arvada, Colorado 80004
June 3, 1998