[TowerTalk] Ground radials- the long and short of it -
Anotherquestion
Tom Rauch
w8ji at contesting.com
Fri Oct 22 16:18:01 EDT 2004
> With respect to the "radial field", how essential is it
> to have the radials evenly spaced in a full circle?
Say you have one radial. The largest improvement occurs when
you add one more radial 180 degrees from it. Add two more,
and the largest improvement is when they fill in the hole.
When any two wires eventually get where the open end spacing
or largest gap is .025 to .05 wl, they pretty much appear
electrically as a single solid sheet.
If you keep all of that in mind, you will know the answer to
your question. If you have wires within .025 to .05wl
maximum spacing, it does no good to add more. If you want to
add some, narrowing the widest gap will generally improve
things the most.
> Or asked another way, if you can get 40-50 1/4 wave
> radials down, but you have to eliminate 40 or 50% of
> the "circle", how dramatically would that affect
performance?
Depends on the antenna you are using. With a short vertical
having low internal loss, it would seriously hurt
efficiency. As a matter of fact if you had 40-50 quarter
wave radials in 180 degrees, you would be wasting wire. You
could reduce that number to 20-30 and have almost no change.
It's not how big you make it, it's how you make it big. Use
as many as long as you can but spread em out as much as
possible.
More information about the TowerTalk
mailing list