[TowerTalk] 160M Wire Antenna

[n4kg@juno.com]

N4KG comments follow:

On Sat, 22 Apr 2000  "Bill Turner, W7TI" <w7ti@jps.net> writes:
> 
> >On Fri, 21 Apr 2000 07:03:43 -0700, "Al Williams"
> ><alwilliams@olywa.net> wrote:

> >My observations using EZNEC are that all horizontal single wire 
> antennas (except several wavelengths)
> > >under ~100' high radiate about equally i.e. straight up!
> > >
> > >The only difference is how easily they tune.
> > >Any disagreements?
> > >
> > >k7puc
> >__________________________________________________________________
> I'd agree that the MAXIMUM radiation is straight up, but a 160 meter
> inverted vee with the apex at 100 feet and the legs 90 degrees apart
> is only 5 db down at a 30 degree takeoff angle.  Not as good as a
> vertical over perfect ground, but not too bad either.  Lots of DX can
> be worked with that.
> 
> Another interesting characteristic of inverted vees is that when the
> apex is roughly 1/4 wavelength high or less, they are almost 
> perfectly
> omnidirectional in the azimuth plane.  There is no "donut" pattern
> typical of horizontal dipoles.  This is not always desirable, but it
> does mean that you can orient it any way you like without having to
> worry about either favored or null directions.
> 
> W7TI

# # # # # #   N4KG reply:

The price paid by inverted vees for "omni-directional" coverage 
is signal LOSS.  When the ends of the antenna are below 1/4 WL,
ground losses go UP.  Yes, it is possible to work DX this way,
but a BETTER solution is TWO horizontal dipoles perpendicular
to each other as HIGH as possible (up to 1/2 WL).

On 80M, I have installed a horizontal dipole broadside NE / SW
between two 130 ft towers and an inverted vee broadside JA / S.A.
with the apex at 140 ft.  At sunrise  / sunset, these antennas
are EXTREMELY  EFFECTIVE, even on receive, to where they
are often better than my Beverages, (or vertical), especially for 
weak long haul signals such as VK0IR, XZ0A, BQ9P, BV,  BY
V85HG, XX9TRR, XU7AAV, 3W5FM, 9M8DB.

de  Tom  N4KG


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