Topband: Multiple Ground Systems

[Tom Rauch]

>I have always disbelieved the "bond the crossing radials" 
>old wives tail, for good electrical reasons... These 
>crossing radials have differing RF phase and voltage on 
>them... Bonding them together is a short circuit causing a 
>lump in the radial field pattern...
>  Case in point:
>  About 10 years ago I had a 4 element, 160 array with 8 
> elevated radials under each vertical - the array was 
> parasitic not an all driven... Of course the elevated 
>  >radials crossed each other but they were
< Snip>

What that proves  more than anything  is the radials in a 
small elevated radial system are significant nearfield 
radiators and not "grounds". It simply proves the fields are 
very concentrated near the wires and are not "spread out" 
and are not low level near each radial like they are in a 
conventional or large ground system.

It doesn't relate or apply at all to use of a common buss 
along the area bisecting adjacent radial fields.

In truth, other than work or money, there is very little 
difference between isolating and laying radials in a 
straight line radially in a multi-element array and using a 
large buss at a point bisecting the pattern of the elements 
when the ground system is doing its job and isn't part of 
the . All those BC stations all those years weren't all that 
dumb, they knew what they were doing. The system they used 
worked very well and caused no problems as applied to a 
non-resonant ground system.

The other way would work also, just keep the wires bonded or 
isolated.

I wouldn't expect bonding to work in a system that has very 
intense voltages and currents on each radial.

73 Tom