Topband: T Top Verticals and yagis

[Guy Olinger K2AV]

Have to disagree on the no-use-for the horizontal leg.

It fills in the doughnut hole in the high angle radiation, which in
contests is very good for keeping others from planting on your run
frequency. Also there are high angle path opportunities that are gradually
becoming more recognized. PLUS, the horizontal section does not remove
power from the vertical wire. In front of the vertical, the direction with
the horizontal pulling away from the bend in the opposite direction, there
is a good deal of net field reduction at the ground. This power, not lost
in the ground, is instead left in the pattern. This is discussed in k2av.com
with illustrations. Click on "Design an Inverted L", then down at the
paragraph "Vertical WIre part of the L" and following.

Also the radiation of the horizontal wire off its end quadrants is
vertically polarized, not horizontal.

Not desired energy off the horizontal wire is a gross oversimplification,
that has stuck around for entirely too long.

73, Guy K2AV



On Sat, Feb 29, 2020 at 12:38 PM Ed Sawyer <sawyered at earthlink.net> wrote:

> Mike, I am not sure where you find your information, but  ALL of the
> radiation of a T top vertical is vertically polarized assuming the T
> section
> is balanced.  The whole point of the T is that the horizontal portions of
> the radiation cancel themselves out because they are 180 degs out of phase.
> Providing loading but not distorting the vertical pattern and not using
> that
> wasted horizontal energy.
>
>
>
> An inverted L, while simple, is exactly the opposite. A portion of the
> energy is in the vertical section and a portion in the horizontal section.
> On 160M, whatever the length is of the horizontal section, its not desired
> energy for DX work.  Although it may actually be helpful as a more
> all-around antenna for local and DX work for this reason.
>
>
>
> The smaller the ratio of horizontal to vertical, the less this compromise
> exists.  However very few stations that say they are using an inverted L on
> 160 have 100ft plus of it vertical.  Much more typical is 50 - 75 ft.  And
> the horizontal portion is usually longer, sometime a lot longer, than the
> vertical portion.
>
>
>
> Ed  N1UR
>
>
>
>
>
> _________________
> Searchable Archives: http://www.contesting.com/_topband - Topband
> Reflector
>