Jim Kelly wrote,

All can probably also agree that you seem more interested in your
correspondent than in antennas.

jk


That's a cheap shot, but it's a cheap shot worth thinking about. Sometimes
the users's expectations and expertise - or lack thereof - are the deciding
factors
in whether something "works" or not. The EH antenna may work for some people
in the way that homeopathy, brightly colored sugar pills, and other quack
remedies work in medicine, but Richard is right, the technical qualities of
antennas
can't be revealed by testimonials or protestations of faith.
73,
Tom Donaly, KA6RUH

Tdonaly wrote:

Jim Kelly wrote,

All can probably also agree that you seem more interested in your
correspondent than in antennas.

jk



That's a cheap shot, but it's a cheap shot worth thinking about. Sometimes
the users's expectations and expertise - or lack thereof - are the deciding
factors
in whether something "works" or not. The EH antenna may work for some people
in the way that homeopathy, brightly colored sugar pills, and other quack
remedies work in medicine, but Richard is right, the technical qualities of
antennas
can't be revealed by testimonials or protestations of faith.


I read a couple pdf's on the things where a couple hams tested 20 meter
backpacker against a dipole.

When the test signals were coupled with a very short length of coax to
the antenna, the EH didn't perform well at all. When coupled with a 1
wave length of coax, the feedline radiated, but not very efficiently,
around 1% as efficiently as the dipole, IIRC. Forgive the numerical
blunders, it was late, and I might have slipped a number or two! 8^)

A long coax version fared better against a vertical in a second test,
but in all fairness, the vertical had a pretty lousy ground.

But okay, the thing worked. The authors concluded that what they had
was a tuned circuit on the end of some coax, and the coax radiated more
so than the antenna. This sounds almost like aa halfwave antenna with
it's tuned circuit. Any relation there?

All in all, it sure seems like a lot of trouble for a so-so antenna,
and since I don't particularly like RF burns and radiating coax, I think
I'll pass! 8^)

- Mike KB3EIA -

But okay, the thing worked. The authors concluded that what they had
was a tuned circuit on the end of some coax, and the coax radiated more
so than the antenna. This sounds almost like aa halfwave antenna with
it's tuned circuit.

The problem with the EH and CFA as has been pointed out many times is the
claim to provide Electromagnetic radiation through Poynting Vector Synthesis.
They produce the E and H field seperately and combine the two in the antenna to
produce EM radiation. The claim is with this Synthesis, high radiation
efficiency is produced from a very small antenna, the Holy Grail, a small
efficient antenna.
If someone gets results from one of these antennas, it is due to feedline
radiation, so they will proclaim "it works". But it does not work because of
Poynting Vector Synthesis as claimed. There are a number of ways to get your
feedline to radiate, the EH antenna could be one of the better ones, along with
the commercial Bilal Isotron.



73 Gary N4AST

JGBOYLES wrote:

But okay, the thing worked. The authors concluded that what they had
was a tuned circuit on the end of some coax, and the coax radiated more
so than the antenna. This sounds almost like aa halfwave antenna with
it's tuned circuit.


The problem with the EH and CFA as has been pointed out many times is the
claim to provide Electromagnetic radiation through Poynting Vector Synthesis.
They produce the E and H field seperately and combine the two in the antenna to
produce EM radiation. The claim is with this Synthesis, high radiation
efficiency is produced from a very small antenna, the Holy Grail, a small
efficient antenna.

Hmm, maybe Occam's razor should be invoked?

If someone gets results from one of these antennas, it is due to feedline
radiation, so they will proclaim "it works". But it does not work because of
Poynting Vector Synthesis as claimed. There are a number of ways to get your
feedline to radiate, the EH antenna could be one of the better ones, along with
the commercial Bilal Isotron.

At least the Isotrons are kinda cool looking... 8^)


- Mike KB3EIA -