HFU HF Underground
Technical Topics => Equipment => Topic started by: kris on October 27, 2022, 2107 UTC
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Easy to hide antenna for FB!
Maybe someone will check how it works?
https://6p3s.ru/en-low-band.php (https://6p3s.ru/en-low-band.php)
- thanks Ray for the explanation! This "mini-whip EH" looks too modest to be a hit with broadcasters.
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That miniature antenna is an English idea from the end of the 1980's.
No one wanting to test it in the West, the inventor went to Egypt, and built a new form.
He was claiming not bad efficiency, but hid that the station power had been raised to a strong 100 kW or more !
So far, can't remember the names. Going to my book shelf.
Got it : it's the EH Antenna, formerly called Cross Field Antenna, designed by Maurice Hately,
claiming that it creates the E and H fields separately.
The point is that the efficiency is low, unless the coax line becomes the real radiating part.
All the details in "Stealth Antennas" by Steve Nichols (G0KYA) published by RSGB in 2010-2013. The author built his own one, got sometimes good results, then bad results, and finished using the components for other projects. Saying it's controversial, but in 6 pages, there's enough practical details to build one. Maybe not worse than the other antennas of the same size, but well below a standard dipole in the SW bands.
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From what I've read, and understand from my education, it is based on flawed physics. Although the antenna might radiate, it is not because of the theory claimed for it.
Basically, you cannot make EM radiation by creating separate magnetic and electric fields. Radiation is created in the form of linked E and H fields by the fundamental physics of accelerating charge. You can't force that link to happen from separate sources.
A good run down on some of the details here, along with why it appears to work https://www.w8ji.com/e-h_antenna.htm (https://www.w8ji.com/e-h_antenna.htm)