JS,

The "Box Tie" design concept can also be applied to a High
Frequency (HF) Shortwave Band Antenna in the form of Two
'equal' Dipoles Fed at 1/4 WL above ground level; with
one Pair of the Dipole Arms Slanting "Up" to 3/8 WL; and
the other Pair of the Dipole Arms Slanting "Down" to 1/8 WL.
The result could be an Antenna with greater Broad-Banded
Characteristics an enhanced Frequency Coverage.
http://groups.yahoo.com/group/Shortw...a/message/6140

For the 31 Meter Band these "Bow Tie" {Paired} Dipoles
would have Four Arms of 24.2 Feet with a Tip-to-Tip Span
of 48.5 Feet. Having a Ground Foot Print of 42 Feet.

For the Shortwave Listener (SWL) these "Bow Tie" {Paired}
Dipole Antennas : One a "V" Dipole and the other an and
Inverted "V" Dipole would use a 4:1 Matching Transformer.

Converting these Two "Bow Tie" Dipoles Antennas to a Pair
of Loop Antennas : The "Ends" could be 'jumpered' with a
Vertical Wire and the Two Dipole Antennas could become Two
Loop Antennas. In this case the Wire Loop Elements would
have to be Re-Shaped and Re-Sized with the the Up and Down
Slanting Arms of 19.4 Feet and Vertical Ends of 9.7 Feet
for a Total of 48.5 Feet. (Two Half Wave Length Loops)


Here are some Shortwave (SW) Band Dipole Antenna Sizes :

60 Meter Band Dipole Antenna would have Arms of 47.7 Feet
with a Tip-to-Tip Span of 95.4 Feet.

49 Meter Band Dipole Antenna would have Arms of 38.7 Feet
with a Tip-to-Tip Span of 77.4 Feet.

41 Meter Band Dipole Antenna would have Arms of 32.4 Feet
with a Tip-to-Tip Span of 64.8 Feet.

31 Meter Band Dipole Antenna would have Arms of 24.2 Feet
with a Tip-to-Tip Span of 48.5 Feet.

25 Meter Band Dipole Antenna would have Arms of 19.7 Feet
with a Tip-to-Tip Span of 39.5 Feet.

22 Meter Band Dipole Antenna would have Arms of 17.1 Feet
with a Tip-to-Tip Span of 34.1 Feet.

19 Meter Band Dipole Antenna would have Arms of 15.1 Feet
with a Tip-to-Tip Span of 30.3 Feet.


iane ~ RHF
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= = = In ,
= = = "J. Steffes" wrote:

It's true!

The concept is demonstrated by the old "bow tie" antenna used
for UHF TV reception.

It was merely two V shaped pieces of metal opposing each other
and terminated the the points of the V. In theory, the two V
sections on their sides looked like this and behaved like
a broadband verticle antenna with continuously changing
wavelengths provided by the V geometry.

It was much easier to fabricate a metal V for a smaller
wavelength antenna than fan out seperate dipoles for a
bunch of UHF frequencies!

John
ARS KE0GG
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= = = Joe Strain wrote:

Do I understand Boyd's "fan antenna" correctly?

The different cut-to w/l lengths tend to collect the
frequencies they are most resonant with and they all
funnel down to the balun where they are electro
magentically mixed for presentation to the receiver ?

Have I boiled the theory down correctly

If that's the case, Avoiding the use of traps and
lengths that such designs employ, which might be
dififcult to string, it's simplicity is elegant !

Yodar
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= = = Jack Painter wrote:

A "fan" of one or two shorter antennas under the main long
sloping wire, and tied to the same feedpoint at the Balun
as 'theboyd' suggested works very well. Use insulators and
non-conductive line to tie each 'fan' segment back to the
main antenna. No antenna swithes are required.

This configuration even works for transmit with a tuner.

Jack
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Tous Sont Bienvenus ! - - - Groupe par Radio
d'auditeur d'onde courte pour des Antennes de SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Alle Sind Willkommen ! - - - Shortwave Radiozuhörer
Gruppe für SWL Antennen
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Tutti Sono Benvenuti ! - - - Gruppo Radiofonico
dell'ascoltatore di onda corta per le Antenne di SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Todos São Bem-vindos ! - - - Grupo de Rádio
do ouvinte do Shortwave para Antenas de SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
Ð’Ñ�е Ð*адушны ! - - - Группа оператора
на приеме коротковолнового диапазона
Radio дл� Aнтенн SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
¡Todos Son Agradables! - - - Grupo de Radio del oyente
de la onda corta para las Antenas de SWL
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
= = = = = Translation = = = = =
All are Welcome - - - To Join the Shortwave Listeners
(SWL) Antenna Group on YAHOO !
http://groups.yahoo.com/group/Shortwave-SWL-Antenna/
.
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