From: DAVID CUTHBERT
Mike,
each metal fence post capacitively couples to the Beverage wire and this is
the 7 mA we see in the EZNEC simulation. However, the resulting current area of
2 amp-ft is quite small compared to the Beverage current-area of 500 A-ft. A
bit of pattern fill and very slightly reduced F/B ratio is the end result. The
added capacitance to GND reduces the Beverage characteristic impedance but not
by much.
The fact that the metal fence runs continuiously under the Beverage above
would IMHO need to be added to the modeling assuming that there is some sort of
electrical connection to all the posts and pipes as galvanized steel fencing
normally provides.
There however some options you may consider:
Replace some of the steel strands in the fence every 30 to 50 feet with a non
conductive weave and where the top rails couple change to a PVC coupler.
You could also put a gate in the fence at another break point...everyone
break up of the long fence would allow the wire above to be more like a
Beverage. if it were me I would take down the fence and replace with a wooden
Jack Fence which are perfect for the Beverage users as a support.
Cheers,
Herb Schoenbohm, KV4FZ.
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