Beware of some types of porcelain insulators that have a hole that is not
glazed, and so is very abrasive. Over time, movement of the wire inside
that rough hole (from the wind, etc.) has been known to wear off the
plating on the wire where it passes through, exposing the steel core to
rust. W8JI mentions this on
www.w8ji.com/beverages.htm :
"Ceramic post insulators may look great, but they do not allow floating the
wire across the insulator. Even if you do manage to find a ceramic
insulator that allows floating the wire, the ceramic will quickly wear away
at the constantly moving wire. Avoid ceramic insulators, unless you are
prepared to "buffer" the wire through a UV resistant soft plastic bushing!"
I sometimes use round plastic insulators with a lag screw molded into them
at right angles to the hole. They have a slot at angle to the hole to
insert the wire, so that after the wire is tensioned it cannot jump out.
There were some photos on Picasaweb linked to from my Beverage antenna
page*, but I see that Google has taken that site down.
*www.w0btu.com/Beverage_antennas.html
73, Mike
www.w0btu.com
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