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[email protected] · October 12th 14, 09:07 PM posted to rec.radio.amateur.antenna

Ian Jackson wrote:
In message ,
writes
Ralph Mowery wrote:

wrote in message
...
I've done a lot of modeling with V's and inverted V's. Except for a slight
diffenence due to ground effects at low heights, there is no difference
between them.

As the angle goes from 180 degrees, i.e. a dipole, the impedance goes
down and and the pattern spreads out.

I have not played with the programs , but often wondered what the effect is
on antennas that are suported on the ends and the middle is dropped in a U
or V shape and not the inverted V shape. Many antenna books and articals
seem to show the flat top and inverted V paterns, but I have not seen any
with the actual V type.

Like I said, there is no difference in free space between a V and an
inverted V.

There are slight differences when close to ground.

Assuming it's a halfwave dipole, I would have thought it was better to
concentrate on getting the centre (where the current is) as high as
possible, rather than the ends. [Obviously this depends on whether you
have a suitable sky-hook available for and at the centre.] However, I
believe that there is at least one commercial loaded dipole (essentially
for portable use, I think) that has a short mast, and the ends of the V
are up in the air.

Model it let me know what you find.

Also, regarding the radiation pattern, as the ends are dropped, doesn't
the signal that starts coming off the ends have an increasingly
vertically-polarised component?

As I recall, yes, the vertical component increases with decreasing angle.

--
Jim Pennino