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Old September 18th 05, 10:11 AM
Lee
 
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Default E H Antenna

Just heard mention of the EH Antenna and that it is rather small but equal
radiation to a full size dipole !!!.

If this is true, i am very interested as i only have a small garden (35x18
feet) and the EH sounds ideal so anyone with info , it would be greatly
appreciated.

I am using a homebrew helical for 80m and a sloping half size G5RV and i am
really stuck for space :-/

Lee.....G6ZSG..


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Old September 18th 05, 10:20 AM
F8BOE
 
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Was interested too, but gave up. With so many different descriptions for one
concept, there must bee something foolish. And I don't want to use my rig
as an antenna!

73 de F8BOE Olivier ...-.-


Lee wrote:

Just heard mention of the EH Antenna and that it is rather small but
equal radiation to a full size dipole !!!.

If this is true, i am very interested as i only have a small garden (35x18
feet) and the EH sounds ideal so anyone with info , it would be greatly
appreciated.

I am using a homebrew helical for 80m and a sloping half size G5RV and i
am
really stuck for space :-/

Lee.....G6ZSG..


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Old September 18th 05, 12:46 PM
Reg Edwards
 
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Just heard mention of the EH Antenna and that it is rather small
but equal
radiation to a full size dipole !!!.

===========================

Sucker! If you believe that then you'll believe anything.


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Old September 18th 05, 01:17 PM
Lee
 
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"Reg Edwards" wrote in message
...
Just heard mention of the EH Antenna and that it is rather small

but equal
radiation to a full size dipole !!!.

===========================

Sucker! If you believe that then you'll believe anything.



Hi Reg......how so?, i regard you as among the knowlegeable and look forward
to your thoughts on the EH that prompts your comment, `tho it does seem like
something for nothing, i don`t wish to appear too dumb!!....i`m currently
playing with a helical on 40 and am thinking of making a dipole with a
matching helical, i can get that in my postage stamp garden......hi

So you think the EH is a waste of time then??? ;-)

Lee.....G6ZSG...



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Old September 18th 05, 02:24 PM
Reg Edwards
 
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"Lee" wrote

Just heard mention of the EH Antenna and that it is rather small

but equal
radiation to a full size dipole !!!.

Sucker! If you believe that then you'll believe anything.


Hi Reg......how so?,

============================
Hello Lee,

The EH antenna is a hoax perpetrated by somebody who hopes to make
money by selling them. His sales description of how the thing works
pretends to make use of the mathematical works of James Clerk Maxwell.
It may sound good to novices but is just a load of nonsense.

Actually, its performance is somewhat worse than other antennas of the
same physical size.

If it's claims are as marvellous as all that, ask yourself why every
amateur doesn't have one, regardless of how big is his backyard. To a
smaller extent, the G5RV falls into the same category.

You did right to ask your question.
----
Reg.




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Old September 18th 05, 02:37 PM
Cecil Moore
 
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Reg Edwards wrote:

Just heard mention of the EH Antenna and that it is rather small
but equal radiation to a full size dipole !!!.


Sucker! If you believe that then you'll believe anything.


Now, now, Reg. He didn't say equal RF radiation.
Heat is also radiation. :-)
--
73, Cecil http://www.qsl.net/w5dxp

----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
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Old September 18th 05, 02:48 PM
Lee
 
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"Reg Edwards" wrote in message
...

"Lee" wrote

snip

Hi Reg......how so?,

============================
Hello Lee,

The EH antenna is a hoax perpetrated by somebody who hopes to make
money by selling them. His sales description of how the thing works
pretends to make use of the mathematical works of James Clerk Maxwell.
It may sound good to novices but is just a load of nonsense.

Actually, its performance is somewhat worse than other antennas of the
same physical size.

If it's claims are as marvellous as all that, ask yourself why every
amateur doesn't have one, regardless of how big is his backyard.


Yes, it did cross my mind but i`ve only just heard of it and as i say, i`m
dumb but not too dumb !!! ;-)

To a
smaller extent, the G5RV falls into the same category.


Oh!, i`ve got one of those as a sloper........seems to work somewhat, not
brilliant but i can hear stations..... LOL....(wish my garden was bigger
:-/).


You did right to ask your question.


I have an enquiring mind ... ta!.

Lee..



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Old September 18th 05, 04:07 PM
Reg Edwards
 
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"Lee" wrote -

i`m currently
playing with a helical on 40 and am thinking of making a dipole with

a
matching helical, i can get that in my postage stamp garden ......

==================================

A back-to-back horizontal helical dipole is a good proposition.
Radiating efficiency is what matters with physically small antennas.
The radiating pattern is whatever you happen to get.

A 1/2-wave helical resonant dipole is considerably more efficient than
a 1/4-wave vertical simply because of the absence of ground connection
losses.

A low dipole does have a small ground loss due to its proximity to
ground. Ideally its height should be at least equal to its overall
length but half that is a satisfactory compromise.

A horizontal helical dipole is the same as a centre-loaded wire with a
very long loading coil. It is easier to match to a feedline than a
vertical and there is a choice of type of line and line impedance.

Either coax or balanced line can be used. Make the loading coil
continuous through the antenna centre and enclose the centre with a
link coupling to the feedline. The number of turns on the coupling
link is dependent on line impedance.

The antenna itself is electrically isolated from the line and remains
nicely balanced about ground.

The greater the diameter of the loading coil former, a rigid plastic
pipe, and the thicker the wire, the higher the efficiency. For 100
watts transmitters, close wound turns of thick enamelled wire are
usually OK.

Resonant frequency is adjusted by pruning the length of the wire or
rods which extend beyond the ends of the coil. If essential due to
space limitations, the end wires can be allowed to fall down towards
the ground but not allowed to swing about in the wind.

Short loaded antennas are essentially single frequency, very narrow
bandwidth devices.

Download program MIDLOAD from website below. It may be of assistance
or at least provide you with something to think about.

In postage-stamp backyards, size-for-size, Magloops are the most
efficient of all very small antennas and can cover several adjacent
bands, but are deceptively difficult/easy/expensive to construct
depending on your ingenuity. Download program MAGLOOP4.
----
.................................................. ..........
Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
.................................................. ..........


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Old September 18th 05, 04:17 PM
Ian Jackson
 
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Default

In message , Reg
Edwards writes

"Lee" wrote

Just heard mention of the EH Antenna and that it is rather small
but equal
radiation to a full size dipole !!!.

Sucker! If you believe that then you'll believe anything.


Hi Reg......how so?,

============================
Hello Lee,

The EH antenna is a hoax perpetrated by somebody who hopes to make
money by selling them. His sales description of how the thing works
pretends to make use of the mathematical works of James Clerk Maxwell.
It may sound good to novices but is just a load of nonsense.

Actually, its performance is somewhat worse than other antennas of the
same physical size.

If it's claims are as marvellous as all that, ask yourself why every
amateur doesn't have one, regardless of how big is his backyard. To a
smaller extent, the G5RV falls into the same category.

You did right to ask your question.
----
Reg.



Didn't Radio 252 (252kHz) near Dublin start out using an E-H antenna?
And wasn't there a new high-power SW station in Egypt which was supposed
to use one too? I've feeling that with the latter, they pulled it down
and used a conventional antenna.
Ian.
--

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Old September 18th 05, 04:33 PM
Lee
 
Posts: n/a
Default


"Reg Edwards" wrote in message
...

"Lee" wrote -

i`m currently
playing with a helical on 40 and am thinking of making a dipole with

a
matching helical, i can get that in my postage stamp garden ......

==================================

A back-to-back horizontal helical dipole is a good proposition.
Radiating efficiency is what matters with physically small antennas.
The radiating pattern is whatever you happen to get.

A 1/2-wave helical resonant dipole is considerably more efficient than
a 1/4-wave vertical simply because of the absence of ground connection
losses.

A low dipole does have a small ground loss due to its proximity to
ground. Ideally its height should be at least equal to its overall
length but half that is a satisfactory compromise.

A horizontal helical dipole is the same as a centre-loaded wire with a
very long loading coil. It is easier to match to a feedline than a
vertical and there is a choice of type of line and line impedance.

Either coax or balanced line can be used. Make the loading coil
continuous through the antenna centre and enclose the centre with a
link coupling to the feedline. The number of turns on the coupling
link is dependent on line impedance.

The antenna itself is electrically isolated from the line and remains
nicely balanced about ground.

The greater the diameter of the loading coil former, a rigid plastic
pipe, and the thicker the wire, the higher the efficiency. For 100
watts transmitters, close wound turns of thick enamelled wire are
usually OK.

Resonant frequency is adjusted by pruning the length of the wire or
rods which extend beyond the ends of the coil. If essential due to
space limitations, the end wires can be allowed to fall down towards
the ground but not allowed to swing about in the wind.

Short loaded antennas are essentially single frequency, very narrow
bandwidth devices.

Download program MIDLOAD from website below. It may be of assistance
or at least provide you with something to think about.

In postage-stamp backyards, size-for-size, Magloops are the most
efficient of all very small antennas and can cover several adjacent
bands, but are deceptively difficult/easy/expensive to construct
depending on your ingenuity. Download program MAGLOOP4.


Yes had a look at that one, gave me a few ideas as i like constructional
projects.....You`ve given me a lot to think about Reg, it`s either a helical
dipole or a magloop ..... there is a helical 40mtr beam in the ARRL handbook
i`ve been looking at too....

Thanks .

Lee.




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