For simulating a solid conducting plate in NEC with wires, Roy Lewallen
(EZNEC author) advises 0.1 wavelength on a side squares of wires. That
would be 16m for topband. Since adding the mesh is a search for tenths
more db's, be conservative and use half his recommendation, 8m or 25'.
If a reasonable radial field of 36 wires x 125' were installed, then
pi*D/36 = 21' tip separation (or do the trig for 10 deg angles).
However, buried radials don't need to be 125' long due to the effects of
ground, thus the tips will be closer together.
So IMO, based on that guidance, matting at topband wavelengths is not
worth it, especially considering how close together wires are near the
base of a vertical.
If a research answer is required, with NEC4.2 (EZNEC Pro/4) you can bury
a mesh in the ground, connect it to the radials, and analyze it. NEC2
will give close answers with radials and the mesh an fraction of an inch
above ground at a fraction of NEC4 cost. It would be a real PITA to
build the wire model for radials and a square mesh since wires have to
connect at segment junctions.
Grant KZ1W
On 6/4/2018 0:04 AM, Raymond Benny wrote:
Peter:
Is this a question or what you are saying is a know fact?
I am very interested in this outcome since I will a installing a TX 4SQ
system where some existing ground radials. Over time, I have heard both
pros and cons on this subject. I would like to read some research or
documentation on this subject.
Tnx,
Ray,
N6VR
Near Prescott, AZ
On Sun, Jun 3, 2018 at 1:14 PM, Peter Bertini <radioconnection@gmail.com>
wrote:
Why would bonding the added matting be required if it is laid over or
beneath an existing radial field? It reduces ground losses regardless.
Peter
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