To determine the horizontal wire current, download the free EZNEC demo
from http://eznec.com. That's exactly the kind of thing it's good for.

If you put a single horizontal wire out to make an L shape, the wire
radiates a considerable amount. Being as low as it is, a lot of the
power will be dissipated in the ground, and only a small fraction will
be radiated at a low elevation angle. But if you connect to the center
of a horizontal wire to make a T shape, the fields from the two halves
of the horizontal wire will nearly cancel, so it'll radiate very little.
Its main effect, like a capacitive top hat, will be to even out the
current in your vertical wire, which will raise the radiation resistance
and therefore the efficiency.

EZNEC or a similar program will quickly show you the differences in
field strength in various directions for the antenna as it is, and with
either of the top loading configurations.

Roy Lewallen, W7EL

dansawyeror wrote:
Roy,

Thanks. This might be feasible. The site would support 50 foot wire from
the tip. At 500 watts what would the current in the horizontal leg be?
In other words what is the minimum effective gage?

What is the purpose of this leg? Is it capacitive or does it begin to
look like something else. What are it directional characteristics?
Dipoles nodes are perpendicular while long wire nodes are parallel.

Dan

Roy Lewallen wrote:

Frank wrote:

. . .
I agree with comments about adding a horizontal wire to the top of
the vertical; it will probably be easier than a capacity hat. I am
overloaded with work at the moment, but would like to attempt a model
in a week or so when I have less work.



Take a look also at a tee type arrangement. That is, a horizontal wire
with the tip of the vertical connected at or near its center. It might
have some advantages over connecting the wire's end to the vertical.
But of course it might be more involved to construct.

Roy Lewallen, W7EL