[TowerTalk] [Bulk] Re: [Bulk] Re: Radials how deep is too deep?

[Grant Saviers]

from the original post

"I guess that my saving grace is that all of the radials are individual 
runs
and could be added or subtracted from the field for testing. The goal for
the radials would be to use them with lowband inverted "L"s  or even a 
shunt
fed tower some day."

As you well know, buried bare radials are the standard for BC stations, 
and as are any ground screens therefore "connected" to earth, but that 
's not the point.  The CW is bare or insulated makes no difference for 
buried wire radials.

If elevated, I agree, don't connect to earth.  Any opportunity to 
provide more shielding  (conductive area) within the buried radial field 
should probably connect to a proximate radial.  Although as I noted, 
there may be pattern distortion.  So it's not my confusion.

Here is a simple thought experiment:  If a vertical was in the center of 
a large concrete slab that was reinforced with the standard 4x4" wire 
mesh, would you connect or not connect to the wire mesh in order to use 
it as a ground screen?

Grant KZ1W

On 12/9/2015 21:46 PM, Jim Brown wrote:
> On Tue,12/8/2015 7:59 AM, Grant Saviers wrote:
>> IMO, connecting radials to the rebar in concrete slabs and 
>> foundations is a good thing. 
>
> There's confusion here. The purpose of radials is to SHIELD the field 
> produced by the antenna from lossy earth, NOT to CONNECT to earth. The 
> intent is that the field couples to the radials and NOT to the lossy 
> earth. So -- unless the radials are for a grounded tower, it is NOT a 
> good thing to connect radials to the tower base. N6LF has also 
> observed that connecting radials to ground tends to make radial 
> currents more unbalanced, which increases ground losses.
>
> 73, Jim K9YC
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