Discussion:
Ground and Antenna
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Giovanni Di Maria
2020-05-14 07:40:23 UTC
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Hi..
I usually project Dipoles and Vertical Antennas (I use 4NEC2)
What is the best ground to use: "Real Ground" o "Perfect Ground" ?
Thank you very much.
Giovanni Di Maria
Jeff
2020-05-14 08:24:08 UTC
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Post by Giovanni Di Maria
Hi..
I usually project Dipoles and Vertical Antennas (I use 4NEC2)
What is the best ground to use: "Real Ground" o "Perfect Ground" ?
Thank you very much.
Giovanni Di Maria
Unless you are modelling vhf and above over a large metal ground plane
use Real Ground.

Jeff
j***@gmail.com
2020-05-16 08:23:08 UTC
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Hi Giovanni

I've not used it much myself, but from what I read more people use real ground. I've seen assertions that if the antenna "works" on real ground then it will "work" on perfect ground. I believe the tutorial uses real ground?

But, I think the poitn of the perfect ground is that you can assess how perfect the antenna is before trying over real ground. This document is really interesting: http://www.reeve.com/Documents/Long%20Wavelength%20Array/Reeve_LWA-Model.pdf

73
Jimi
Jeff
2020-05-16 09:35:22 UTC
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Post by j***@gmail.com
Hi Giovanni
I've not used it much myself, but from what I read more people use real ground. I've seen assertions that if the antenna "works" on real ground then it will "work" on perfect ground. I believe the tutorial uses real ground?
But, I think the point of the perfect ground is that you can assess how perfect the antenna is before trying over real ground. This document is really interesting: http://www.reeve.com/Documents/Long%20Wavelength%20Array/Reeve_LWA-Model.pdf
73
Jimi
Perfect ground uses an infinite perfectly conducting ground, and just
reflects the antenna structure. It is a totally unrealistic situation,
and only come close to being useful for VHF and higher antennas that are
mounted on a very large continuous metallic ground plane. ie small
antenna, very very large metal ground plane.

It is not a case of is works on real ground then it will work on perfect
ground, as in almost all cases a perfect ground can never exist in reality.

If you wish to see the difference between how an antenna that needs a
ground plane would work in ideal conditions then a perfect ground will
show you that, but it is rather meaningless because in reality you have
to provide some sort of ground plane yourself, radials etc, which will
severely change the situation from that of a perfect ground.

If you are comparing an antenna that does not require a ground plane,
such as a dipole, model it in free space first, and then add a real
ground so you can see how the height above ground and varying ground
parameters affects the antenna.

Jeff
Giovanni Di Maria
2020-05-16 19:56:20 UTC
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Post by j***@gmail.com
Hi Giovanni
I've not used it much myself, but from what I read more people use real ground. I've seen assertions that if the antenna "works" on real ground then it will "work" on perfect ground. I believe the tutorial uses real ground?
But, I think the poitn of the perfect ground is that you can assess how perfect the antenna is before trying over real ground. This document is really interesting: http://www.reeve.com/Documents/Long%20Wavelength%20Array/Reeve_LWA-Model.pdf
73
Jimi
Thank you very much Jimi.
73 !!!!!
Giovanni

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