[Antennas] 1/4 wave vert - elevated radials
Eric Jones
ejones at hiwaay.net
Fri Aug 22 12:18:08 EDT 2008
de N4TGC Eric
Hi, guys: I'm new to this list, so I don't know what subjects have already
been "dead horsed", but here goes my scenario:
I have a 53' Rohn 25-grade (i.e., light-duty, triangular, tubular-leg) tower
that will eventually (hopefully, before I get too old to climb it) be
extended to ~85'. Currently it has only lightning rods, one off each leg
about a foot out - i.e., no radials, as it was a TV and 6-meter-beam tower
originally. Two basic questions: ARRL pub'ls recommend shunt feed up the
side, similar to the slant-wire feed mentioned - has anyone tried this, and
how well did it work? Secondly, I read recently that breaking the guys up
into non-resonant sections with insulators is not really necessary; that one
"egg" each at the tower end to decouple it is all that's needed. I've been
using a combo of steel guy wire, grounded to the tower, on the lowest trio
and para-cord higher up, but I'm concerned that a taller tower will sway too
much (esp. with me on it!) using stretchy dacron/nylon/whatever-it-is line.
At 60' total it seemed okay, and has been up over eight years that way, but
is now due for guy replacement.
As for ground radials, I'd only have a problem installing them when the
red-clay ground is summer-dry (can't effectively be dug by hand), and 30' to
the north where there's a tree line. While I'm currently using one of the
trees for a guy tether, I could bulldoze the whole line back about another
20'. The other tether points are the facia on my workshop, and a
purpose-built stanchion/clothesline pole. Yeah, I had to wet the ground to
dig that one in!
TIA e
More information about the Antennas
mailing list