[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 



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