Robert,
I would leave it as it is.
I have experimented a lot with sloping top-loading wires and found that 12 -
14 meters (~40') is about right with a 55' vertical section. The only thing
I would do different is use two #14 wires, one on each side of the
spider-pole for a bit wider bandwidth lower losses. And, of course, add more
radials :-)
73,
George,
AA7JV/C6AGU
On Sun, 17 Mar 2019 22:01:54 +0000
"Chortek, Robert L." <Robert.Chortek@berliner.com> wrote:
Fellow Topbanders,
I just finished replacing my damaged base loaded vertical and have a question
about the optimum amount of top loading.
A bit of background - my new vertical is a 55' #12 wire supported by a 60'
Spiderbeam fiberglass pole. At the top there are 2 -41' top loading wires running
roughly at 180 degrees from each other, angling down at about 45 degrees. The ends
are at about 25' . Since the resonant point is about 2 MHZ, I am still using an air
core base loading coil 6" in diameter made of No. 8 solid copper wire to bring
it to resonance at 1825 MHZ.
I could lengthen the top loading wires somewhere between
4 - 10' each (and reduce the amount of base loading needed), but it will bring the ends to within about 15' and 20' of the ground.
My question is this: At what point will lengthening the top loading wires and
bringing the ends closer to ground offset the improvement gained by reducing
the amount of base loading?
As it is, the antenna is a HUGE improvement over my base loaded vertical (on
the order of 6-9 db from stations in the RBN within the ground wave).
Should I leave it alone and be satisfied with the improvement or lengthen the
top loading wires. If so, by how much?
Thanks in advance from any advice.
73,
Bob/AA6VB
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
|