Mark Keith wrote:
He is not testing an E/H antenna. He is
testing a 90 ft tower and feedline, being the problem of common mode
currents on the feedline are severe.

I might add, he is testing a 90 ft tower fed in a less than optimum
manner also...I could shunt feed a 90 ft tower like a normal person
would, and beat his setup any day I bet. If I top loaded the tower with
loading wires or a hat, Look out Mr. E/H ...It ain't gonna be pretty. I
wouldn't have the lossy coil in the "E/H" apparatus to contend with for
one thing. So I bet his test results of feeding the E/H ant-90 ft
tower/feedline combo, most likely are inferior to feeding a 90 ft tower
in a conventional manner, assuming equal ground losses. Note how the
comparison B/C antenna compares overall... So lets see...The price of
a 90 ft tower plus wire for 120 radials, or a $40k+ E/H antenna plus the
90 ft tower as support. He says you don't really need
radials...*snicker*...The E/H antenna setup will most likely be the
poorer performer of the two setups. Dunno, I know which line I'll be
in.. And I can tell you I won't have to drive to GA to pick it
up...:/ MK
--
http://web.wt.net/~nm5k

Walter Maxwell wrote:
"To anyone who believes the W5QJR EH conceptis valid."

OK. I read the first page: "Welcome to the Wonderful World of EH
Antennas". It said nothing of why I should be interested. Why convert an
existing broadcast antenna to EH?

FCC has a publication, "Rules of Good Engineering Practice for Standard
Broadcast Stations" which includes Mv/m at 1 mile on a radial over
perfect earth from a vertical antenna of various heights. It shows about
195 mV/m for a 1/4-wave grounded vertical.

This can be adjusted for any power or diistance from the sender:

E = Eo sq rt P/d

Eo = 195 mV/m for the 1/4-wave antenna at 1 mile

P = the actual radiated power

d = distance from antenna in miles

The mV/m at a mile assumes a perfect ground and a perfect antenna ground
system. FCC says 120 radials equally spaced and 1/2-wavelength long are
its standard. Efficiency typically exceeds 95%.

If the vertical radiator is higher (longer) than !/8-wavelength, the 150
mV/m at 1 mile, required minimum efficiency, can still be met with 120
radials on the earth that are only 1/4-wavelength long. The reduction in
efficiency is small.

Nobody has perfect ground unless he is at sea. For imperfect ground, the
FCC publishes "Ground Wave Propagation Curves" for various soil
conductivities.

In the FCC millivolt per meter numbers for vertical antennas of various
heights, the field strength only increases 5% in going from very short
to a full 1/4-wave height. This requires the near perfect ground. A
3/8-wave radiator only has a 15% advantage over a very short radiator.

If the radiator is a thin wire, bandwidth may be only + or - 1% of the
wire`s resonant frequency. Broadcast stations use towers of substantial
cross section as antennas. These provide several percent of bandwidth
and allow full audio range in the medium wave band.

A short antenna has low radiation resistance and high capacitive
reactance. This requires tuning out the large capacitive reactance
(small capacitance) with an equally large inductive reactance (large
reactor), and matching the very low drivepoint resistance of an
end-driven vertical to the higher impedance sending circuit. Resistance
involved in neutralizing reactance and matching the antenna to the
source is likely to be lossy for the too-short antenna. Walter has
already pointed this out.

Why would the EH antenna have interest?

Best regards, Richard Harrison, KB5WZI

On Wed, 14 Jan 2004 11:17:24 -0600 (CST), (Richard
Harrison) wrote:

Walter Maxwell wrote:
"To anyone who believes the W5QJR EH conceptis valid."


Why would the EH antenna have interest?

Best regards, Richard Harrison, KB5WZI

Richard, my point is that the EH antenna, as Ted Hart claims it, cannot exist.
He claims that by feeding the antenna with current lagging voltage by 90 degrees
it puts the E and H fields in time phase. This is impossible, totally violating
the principles of electromagnetic theory. Ted's claim shows misundstanding of
the theory of wave propagation.

Walt

Walter Maxwell wrote:
Richard, my point is that the EH antenna, as Ted Hart claims it, cannot exist.
He claims that by feeding the antenna with current lagging voltage by 90 degrees
it puts the E and H fields in time phase. This is impossible, totally violating
the principles of electromagnetic theory. Ted's claim shows misundstanding of
the theory of wave propagation.

Well Walt, look at it this way. By claiming he puts the E and H fields in
phase, he forces the ExH power flow vector to be equal to zero. :-)
--
73, Cecil http://www.qsl.net/w5dxp



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And I almost had my Fractal, EH, CFA completed. Are you saying my dream of a
24 inch 5dBd gain 75 meter antenna has been shattered?

"Cecil Moore" wrote in message
...
Well Walt, look at it this way. By claiming he puts the E and H fields in
phase, he forces the ExH power flow vector to be equal to zero. :-)
--
73, Cecil http://www.qsl.net/w5dxp



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w4jle wrote:
And I almost had my Fractal, EH, CFA completed. Are you saying my dream of a
24 inch 5dBd gain 75 meter antenna has been shattered?

Not entirely, I can show you how to get a 22 dBi omnidirectional
radiation pattern with a folded antenna (according to EZNEC. :-)
--
73, Cecil http://www.qsl.net/w5dxp



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"Cecil Moore" wrote in message
...
Well Walt, look at it this way. By claiming he puts the E and H fields in
phase, he forces the ExH power flow vector to be equal to zero. :-)
--
73, Cecil http://www.qsl.net/w5dxp

Yeah, Cecil, that's what I thought, too, but not according to Ted. He puts his
antenna up at 1/4 wl above ground and gets 2.25 dB gain over a standard 1/4 wl
vertical. What am I missing here? Perhaps we just haven't yet found Ted's secret
for squeezing the E and H fields to rest on top of each other instead of in
sequence.

Walt

Walter, W2DU wrote:
"This is impossible, totally violating the principles of electromagnetic
theory."

I agree. It violates first principles of electricity. Radiation is a
resistive load. Voltage across the load coincides exactly with current
through the load. Volts and amps are in-phase. Nothing can be done to
change that. There is no electrical energy storage in a resistance.

Once you tune for unity power factor and match for power transfer,
you`re done and no monkey business will change the radiator from its
natural function. You put a voltage across its drivepoint and it does
its thing independent of how the voltage got there if the source can
supply the antenna`s demand.

Best regards, Richard Harrison, KB5WZI

On Wed, 14 Jan 2004 11:17:24 -0600 (CST),
(Richard Harrison) wrote:


OK. I read the first page: "Welcome to the Wonderful World of EH
Antennas". It said nothing of why I should be interested. Why convert an
existing broadcast antenna to EH?

FCC has a publication, "Rules of Good Engineering Practice for Standard
Broadcast Stations" which includes Mv/m at 1 mile on a radial over
perfect earth from a vertical antenna of various heights. It shows about
195 mV/m for a 1/4-wave grounded vertical.


Let's look at the Data 1 mile out, and compare to the standard antenna
at the same distance:

-3.5dB
-1.24dB
-2.84dB
-1.5dB
+0.66dB (in the direction of the nearby resonating tower)
-0.85dB

How about at the limit of the test @30KM:

-26.9dB
-27dB
-22.7dB
-34.8dB
-29dB @ 16KM (off the chart @30KM)
-32.4dB

This sucker's signal dives right into the ground like a plow.
Obviously the eh antenna suffers a misspelling, it should be POS.

[Art, are you taking notice of the performance of small vertical
dipoles for 160M?]

snip

Why would the EH antenna have interest?

Hi Richard,

Why indeed. This design is a tower mounted, air cooled resistor that
has the advantages of top loading guy wires and nearby resonating
structures (if such could be called advantageous).

If you want to crow about your eh/POS DX contacts 1 mile out, they
better be in the direction of that nearby standard quarterwave
antenna. More's the pity that those living beyond 10 miles may never
hear your fabulous DX report.

73's
Richard Clark, KB7QHC

Richard Clark wrote:
"If you want to crow about your EH/POS DX contacts 1 mile out, they
better be in the direction of that nearby standard quarterwave antenna."

All that needs to be done to take the standard quarterwave antenna out
of the picture is to open-circuit the vertical to ground. That makes it
resonant at about 2X the frequency where it is a 1/2-wave at resonance
and capable of absorbing energy which it reradiates as a parasitic
element. This may not be so good for the 2nd harmonic in some direction.

Best regards, Richard Harrison, KB5WZI