Malcolm Clark wrote:
>
> Wait a minute, aren't you're advocating two opposites to accomplish the
> same thing--round smooth balls and sharp pointed tips. I'll go with the
> sharp and pointed. Eyeball protection is the only valid reason I know
> of for round balls on any antenna. If a smooth round surface was the
> ideal way to bleed of a charge, wouldn't we see round lightning balls
> instead of sharp pointed lightning rods--or am I missing something?
>
they are two different things. the sharp points will enourage corona at
lower field strengths and create the 'charge cloud' that reduces the
field
below it. the questions with these are: is any corona created by the
points
enough to cause noise in a receiver connected to a nearby antenna? is
the
area they protect big enough to reduce corona from other sources?
the smooth round balls increase the field strength needed to start
corona
at the ends of the elements where it would of course be coupled directly
into the receiver. unfortunately the more i think about the old telrex
designs with the balls the less i think they really do. this is due to
all
the other sharp edges... the rivets for the balls, the hose clamps on
the
outer element joints, the bolts through the inner joints of the
elements,
the square corners on the t-match, the boom to element bolts, etc.
--
David Robbins K1TTT (ex KY1H)
k1ttt@berkshire.net or robbins@berkshire.net
http://www.berkshire.net/~robbins/k1ttt.html
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