I'm seeking learned opinions.

I think we refer to "beam antennas" that way because they behave like lamps
with reflectors, directing a beam of RF like a beam of light. I don’t know
the historical accuracy of my thinking.

I've built any number of directional antennas, usually yagis but also quads
for HF and VHF and a 20m Moxon. I never asked about the name before today.
How many elements constitute a beam antenna? (ARRL reminds us that even a
single horizontal dipole has some directivity; they seem to use the word
beam only for antennas of two or more elements.)

"Sal"
(KD6VKW)

In article ,
"Sal M. O'Nella" wrote:

How many elements constitute a beam antenna? (ARRL reminds us that even a
single horizontal dipole has some directivity; they seem to use the word
beam only for antennas of two or more elements.)


I'll respond with three questions.

(1) How many elements does a V beam antenna have?
(2) Disregarding minor lobes, is it unidirectional or bidirectional?
(3) What if it is VERY long and the reflected wave is quite small by the
time it gets back to the feedpoint?

David, VE7EZM and AF7BZ

--
David Ryeburn

To send e-mail, change "netz" to "net"

On 3/21/2016 1:02 AM, Sal M. O'Nella wrote:
I'm seeking learned opinions.

I think we refer to "beam antennas" that way because they behave like
lamps with reflectors, directing a beam of RF like a beam of light. I
don’t know the historical accuracy of my thinking.

I've built any number of directional antennas, usually yagis but also
quads for HF and VHF and a 20m Moxon. I never asked about the name
before today. How many elements constitute a beam antenna? (ARRL reminds
us that even a single horizontal dipole has some directivity; they seem
to use the word beam only for antennas of two or more elements.)

"Sal"
(KD6VKW)
The present pool of questions from NCVEC for the USA Technician exam
contains:
What is a beam antenna?
A. An antenna built from aluminum I-beams
B. An omnidirectional antenna invented by Clarence Beam
C. An antenna that concentrates signals in one direction
D. An antenna that reverses the phase of received signals
It says the correct answer is C. I suppose the issue is what constitutes
"concentrated" signals. A dipole is directional in any plane that
contains the dipole, but not in perpendicular planes. Maybe that is not
concentrated enough...
Bob Wilson WA9D

In message , Jeff writes

I think we refer to "beam antennas" that way because they behave like
lamps with reflectors, directing a beam of RF like a beam of light. I
don’t know the historical accuracy of my thinking.



I think from a historical perspective the name derives from 'Beam
Stations' such as those comprised in the Imperial Wireless Chain. That
is stations that were set up to 'beam' their signals to far flung
places on the globe.

Antennas were not what would be described as beam antennas these days
but were types such as curtain arrays.

Jeff

Surely the term "beam" is generic? I would have thought that any antenna
or antenna system which is deliberately designed to concentrate its
radiation or reception would qualify to be called thus.
--
Ian

Ian Jackson wrote:
In message , Jeff writes

I think we refer to "beam antennas" that way because they behave like
lamps with reflectors, directing a beam of RF like a beam of light. I
don???t know the historical accuracy of my thinking.



I think from a historical perspective the name derives from 'Beam
Stations' such as those comprised in the Imperial Wireless Chain. That
is stations that were set up to 'beam' their signals to far flung
places on the globe.

Antennas were not what would be described as beam antennas these days
but were types such as curtain arrays.

Jeff

Surely the term "beam" is generic? I would have thought that any antenna
or antenna system which is deliberately designed to concentrate its
radiation or reception would qualify to be called thus.

I have often seen amateur literature equate "beam" to "yagi" and
similar antennas, where other forms of directional antenna are referred
to with names like "quad", "dish", "phased array", etc.

Of course these are also beam antennas, but somehow the name beam
sticks to directional antennas of the yagi type.

"Jeff" wrote in message ...


I think we refer to "beam antennas" that way because they behave like
lamps with reflectors, directing a beam of RF like a beam of light. I
don’t know the historical accuracy of my thinking.



I think from a historical perspective the name derives from 'Beam
Stations' such as those comprised in the Imperial Wireless Chain. That
is stations that were set up to 'beam' their signals to far flung places
on the globe.

Antennas were not what would be described as beam antennas these days
but were types such as curtain arrays.
================================================== ===========

I can understand that. Thanks.

"Ian Jackson" wrote in message ...

In message , Jeff writes

I think we refer to "beam antennas" that way because they behave like
lamps with reflectors, directing a beam of RF like a beam of light. I
don’t know the historical accuracy of my thinking.



I think from a historical perspective the name derives from 'Beam Stations'
such as those comprised in the Imperial Wireless Chain. That is stations
that were set up to 'beam' their signals to far flung places on the globe.

Antennas were not what would be described as beam antennas these days but
were types such as curtain arrays.

Jeff

Surely the term "beam" is generic? I would have thought that any antenna
or antenna system which is deliberately designed to concentrate its
radiation or reception would qualify to be called thus.
--
Ian
=================================================

I think that's reasonable. Thanks.

"Rob" wrote in message ...

Ian Jackson wrote:
In message , Jeff writes

I think we refer to "beam antennas" that way because they behave like
lamps with reflectors, directing a beam of RF like a beam of light. I
don???t know the historical accuracy of my thinking.



I think from a historical perspective the name derives from 'Beam
Stations' such as those comprised in the Imperial Wireless Chain. That
is stations that were set up to 'beam' their signals to far flung
places on the globe.

Antennas were not what would be described as beam antennas these days
but were types such as curtain arrays.

Jeff

Surely the term "beam" is generic? I would have thought that any antenna
or antenna system which is deliberately designed to concentrate its
radiation or reception would qualify to be called thus.

I have often seen amateur literature equate "beam" to "yagi" and
similar antennas, where other forms of directional antenna are referred
to with names like "quad", "dish", "phased array", etc.

Of course these are also beam antennas, but somehow the name beam
sticks to directional antennas of the yagi type.
================================================== ===

I agree. I was a satellite TV experimenter years ago and I never thought of
my dishes as "beams."

I comfortably think of my ham yagis as beams, however. Good!

I think "beam" i spolitical name. Antenas with directivity was made by
japanese scientists Yagi and Uda. And after WWII Japan was not very popular
between Americans. So, they name such antennas "beam"



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Sorry for my bad english. Not between americans, among Americans. In
Croatian we use the same word for both terms



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