Topband: Adding chicken wire or mesh on top of radial field

[Grant Saviers]

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 at 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
>> _________________
>> Topband Reflector Archives - http://www.contesting.com/_topband
>>
>
>