The HEBA appears to be the same animal as the CFA (Crossed Field Antenna)
patented by Dr. Kabbary and M.C. Hately in the late 1980s. As the HEBA
Model 103 Performance Analysis says, *" WWAS accomplished this feat of
engineering through the development of a two-element antenna that generates
the electric field and the magnetic field separately."* This is the idea of
the CFA where separately generated E and H fields combine in space to
overcome one or more limitations of conventional antennas.
I thought the CFA was debunked by the time the last one was sold by Dr.
Kabbary's Egyptian antenna company in 2003. Up to that time there were
several articles in AntenneX magazine about the antenna along with attempts
to build and test it. Dr. Kirk McDonald, a regular author for AntenneX,
goes into the math in his paper *“Crossed-Field” and “EH” Antennas
Including Radiation from the Feed Lines and Reflection from the Earth’s
Surface.*
My NEC models at the time for a CFA driven as a standard monopole against
the Kabbary-recommended 2-story, copper strapped building showed it
operating well enough as a standard monopole. The CFA on top of the
two-story building formed a center-loaded monopole. I can build that model
again and report back here if anyone is interested. I will compare them to
the HEBA performance analysis.
Sometime around 2002 an Australian ham/BC engineer worked with Dr. Kabbary
to tune up a CFA at an AM broadcast station in Australia. After Kabbary
give up and returned to Egypt the amateur retuned the antenna as a standard
monopole that exceeded the measured field strength of the CFA tuning. To me
and others the promise of the CFA for topband was a heady time which helped
propel me more deeply into antenna design and analysis. The CFA turned out
to be both a disappointment and a good lesson.
*Wikipedia CFA article*
https://en.wikipedia.org/wiki/Crossed_field_antenna
* “Crossed-Field” and “EH” Antennas Including Radiation from the Feed Lines
and Reflection from the Earth’s Surface*, Kirk McDonald, Princeton
University
http://kirkmcd.princeton.edu/examples/crossedfield.pdf
*HEBA Model 103 Performance Analysis*
https://www.thebdr.net/wp-content/uploads/2020/06/high-efficiency-broadband-plain-english.pdf
Dave KH6AQ
On Fri, Apr 19, 2024 at 6:01 AM Radio KH6O <radio.kh6o@gmail.com> wrote:
> I'd like to see a version of this for 160M:
>
>
> https://www.radioworld.com/news-and-business/headlines/wqvram-is-granted-cp-to-use-heba-antenna-at-night
>
> --
> 73,
> Jeff KH6O / 6
> _________________
> Searchable Archives: http://www.contesting.com/_topband - Topband
> Reflector
>
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
|