Topband: Fence "ground screen" instead of wire radials?

[Herb Schoenbohm]

On 9/2/2011 6:06 PM, Brian Machesney wrote:
>> Thanks to NI0C for reminding me that this info was presented by NC0B
>
Chicken wire or rabbit wire make an inexpensive alternative to an 
expanded copper mesh ground screen.  Just roll it out in multiple 
directions from the tower base and tack it to the ground on top of the 
grass.  The grass will grow through it in a short period and it will be 
invisible.  that is easier than rolling up the sod for sure.  The only 
problem is the connection but since the actual tower is most likely 
galvanized steel there isn't an issue of dissimilar metal just figuring 
out how to making a convenient connection via a galvanize steel bus with 
similar jumpers to the actual tower.  Soldering is not possible and cad 
weld is expensive.  Tinned copper braid jumpers with the proper 
preparation can work and galvanized steel angle brackets as well.  What 
you don't want are a bunch of diodes at the base of the tower which is 
certain to occur with corrosion.  Small jumpers made from 3/8 inch 
strand guy wire are fine using small U-clamps to the screen but should 
be above ground for frequent inspection.

Many know how well a HF or VHF vertical will perform on a steel roof as 
compared to a poor ground.  In fact the screen does not have to be out 
1/4 wave as the major losses in any ground occur closest to the base of 
the tower.  Running a few 1/4 or less radials in the empty spaces 
between screens should not hurt.  With today's copper prices a chicken 
wire screen may do well for you.

Herb Schoenbohm, KV4FZ