What's In a Name -- Of My Antenna?
 

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)

What's In a Name -- Of My Antenna?
 

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"

What's In a Name -- Of My Antenna?
 

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

What's In a Name -- Of My Antenna?
 

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

What's In a Name -- Of My Antenna?
 

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.

What's In a Name -- Of My Antenna?
 

"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.

What's In a Name -- Of My Antenna?
 

"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.

What's In a Name -- Of My Antenna?
 

"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!

What's In a Name -- Of My Antenna?
 

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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What's In a Name -- Of My Antenna?
 

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



---
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What's In a Name -- Of My Antenna?
 

Wor wrote:
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"

Except Yagi and Uda did their work well before WWII.

The term "beam" is nothing more than slang for a directional device.


--
Jim Pennino

What's In a Name -- Of My Antenna?
 

On Sun, 20 Mar 2016 23:02:06 -0700, "Sal M. O'Nella"
wrote:

I'm seeking learned opinions.

Will you settle for uninformed speculation and reverse engineering?

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.

Methinks the origin of the term is from the "death ray" weapons that
paralleled early radio development. The Uda-Yagi antenna was invented
in 1926 which included references to "beam-width" which presumably
referred to a narrow "radio beam" as in a death ray. During the same
time, Marconi, Tesla, and others jumped into the "death ray"
competition, claiming to have invented one:
https://en.wikipedia.org/wiki/Death_ray
Even the invention of RADAR was originally inspired by an attempt to
produce a suitable "death ray". In all cases, the proposed "death
ray" was quite directional as it would not do to vaporize the entire
neighborhood. It was often referred to as a "radio beam" or "energy
beam". So, when you announce that you're "turning the beam" in
someone's direction, please take the time to inform them that it's not
a "death ray" that you're aiming.




--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

What's In a Name -- Of My Antenna?
 

On Wed, 23 Mar 2016 18:29:22 -0700, Jeff Liebermann wrote:

Will you settle for uninformed speculation and reverse engineering?
...
Even the invention of RADAR was originally inspired by an attempt to
produce a suitable "death ray".

Uninformed speculation, indeed.
But, I'm sure once RADAR started being developed and improved,
the military brains of the era thought/sought to weaponize it.

What's In a Name -- Of My Antenna?
 

On 24 Mar 2016 14:02:38 GMT, Allodoxaphobia
wrote:

On Wed, 23 Mar 2016 18:29:22 -0700, Jeff Liebermann wrote:

Will you settle for uninformed speculation and reverse engineering?
...
Even the invention of RADAR was originally inspired by an attempt to
produce a suitable "death ray".

Uninformed speculation, indeed.

Yep. Garbage in. Dogma out.

But, I'm sure once RADAR started being developed and improved,
the military brains of the era thought/sought to weaponize it.

Don't be so sure. The original idea in 1939 was to build a death ray
that would cook the pilot of an attacking German airplane. The
calculations were done and it was determined to be impossible. So,
Watson-Watt asked "What can we do to help". Arnold Wilkins recalled
that it was possible to detect an airplane when it created multipath
interference patterns as the airplane flew between the transmitter and
receiver. A field test was arranged, it worked, and the rest it
history.

https://en.wikipedia.org/wiki/History_of_radar
"...had read about a German newspaper article claiming that
the Germans had built a death ray using radio signals,
accompanied by an image of a very large radio antenna."

This video covers the early RADAR development quite nicely.
"The Secret War_2 To See for a Hundred Miles_complete "
https://www.youtube.com/watch?v=ZPwDicTQVBo (50 min)

Nano-drivel: The maximum width of a boat at the water line is called
the vessel "beam". The -3dB width of an antenna pattern is called the
"beam width". Avast ye scurvy dogs connect the dots.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

What's In a Name -- Of My Antenna?
 

"Wor" wrote in message ...

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"

I don't know the correct definition, but my definition is an antenna array
with inline elements.
Those elements can be parasitic or driven. And they can be dipoles, quads,
triangles or whatever.

What's In a Name -- Of My Antenna?
 

"Wayne" wrote in message ...



"Wor" wrote in message ...

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"

I don't know the correct definition, but my definition is an antenna array
with inline elements.
Those elements can be parasitic or driven. And they can be dipoles, quads,
triangles or whatever.
================================================== ==
I beginning to get the sense that the definition is sufficiently broad that
the antenna in question has to be described in more detail if the term
"beam" is to be applied.

"Sal"

What's In a Name -- Of My Antenna?
 

"Jeff Liebermann" wrote in message
...


Major snippage

Arnold Wilkins recalled
that it was possible to detect an airplane when it created multipath
interference patterns as the airplane flew between the transmitter and
receiver. A field test was arranged, it worked, and the rest it
history.

================================================== =======

I recall an article in an electronics magazine about an aircraft detection
system that worked that way. It was tested in Maryland using the area's TV
station signals.

http://users.ece.gatech.edu/lanterma...ultistatic.pdf

Wikipedia has an article called "Passive Radar."

"Sal"

What's In a Name -- Of My Antenna?
 

On Fri, 25 Mar 2016 21:24:45 -0700, "Sal M. O'Nella"
wrote:

I don't know the correct definition, but my definition is an antenna array
with inline elements.
Those elements can be parasitic or driven. And they can be dipoles, quads,
triangles or whatever.

My definition of an antenna is a matching transformer which matched
the output impedance of a transmitter, with that of free space (377
ohms). Convention has it to name the antenna after the designer. In
this case, Shintaro Uda was the student assistant who designed the
antenna, while Hidetsugu Yagi was his university instructor. Uda
published a paper on the design in Japanese, which nobody seemed to
have noticed. A few years later, Yagi translated the paper into
English, which finally got some attention. Its publication resulted
in the antenna being called a Yagi antenna by the American press. Yagi
repeatedly reminded everyone that it was Uda who had designed the
antenna, and deserved the credit. However, the best that could be
done was the Yagi-Uda contraction, which is awkward and backwards.

http://what-is-what.com/what_is/Yagi_Uda_antenna.html
"Despite the fact that Hidetsugu Yagi never took credit for
the antenna's design, it was his name that the American press
used to refer to the concept."

http://www.radiocomms.com.au/content/industry/article/yagi-the-man-behind-the-antenna-647231587
"The technology is all down to Prof Hidetsugu Yagi and his
assistant Shintaro Uda; more to Uda than Yagi, in fact, so
strictly speaking the design should be known as the Uda antenna,
or at least Yagi-Uda."

Incidentally, I have an FM broadcast Yagi-Uda antenna on my roof that
was made by the Yagi-Uda Antenna Company (or something like that).
I'll see if I can find the documentation and post a copy.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

What's In a Name -- Of My Antenna?
 

On Fri, 25 Mar 2016 21:39:10 -0700, "Sal M. O'Nella"
wrote:



"Jeff Liebermann" wrote in message
.. .


Major snippage

Arnold Wilkins recalled
that it was possible to detect an airplane when it created multipath
interference patterns as the airplane flew between the transmitter and
receiver. A field test was arranged, it worked, and the rest it
history.

================================================= ========

I recall an article in an electronics magazine about an aircraft detection
system that worked that way. It was tested in Maryland using the area's TV
station signals.

http://users.ece.gatech.edu/lanterma...ultistatic.pdf

Wikipedia has an article called "Passive Radar."

"Sal"

More correctly, it's CW radar, where the target is illuminated by a
simple carrier, and the interference pattern is detected by a receiver
located somewhere else. While it is possible to use an RF seeking
missile to remove the transmit source, the receiving station(s) are
difficult to find and detect because they emit no RF. The CW
"illumination" transmitter can also be a broadcast TV station, which
is rather politically incorrect to destroy. Similar systems that use
broadcast, cellular, paging, beacons, and repeaters have been built
and tested. I suppose ham operators could have built such a device,
but were probably discouraged by the airlines and military not
offering QSL cards for tracking their flights:
https://en.wikipedia.org/wiki/Continuous-wave_radar
However, please not that it only works with modulation schemes that
have a carrier. SSB, spread spectrum, and some forms of digital data
don't work.

The original RADAR was RDF (radio direction finding). At the time,
most everyone was thinking in terms of some kind of burglar alarm,
where the aircraft would cross a radio "beam" as in the common optical
door annunciator. Other schemes were based on detecting the IR from
hot engines or engine sounds. When the RDF was thrown together, and
combined with the oscilloscope, the designers were amazed that they
could accurately measure range, as well as follow the path of large
artillery shells. So, the "ranging" was added to the acronym.



11PM and I'm still working in the office. I can see it coming...
dinner at midnight (again). What did I do Friday evenings before I
discovered computahs?



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

What's In a Name -- Of My Antenna?
 

On 3/26/2016 12:53 AM, Jeff Liebermann wrote:
On Fri, 25 Mar 2016 21:24:45 -0700, "Sal M. O'Nella"
wrote:

I don't know the correct definition, but my definition is an antenna array
with inline elements.
Those elements can be parasitic or driven. And they can be dipoles, quads,
triangles or whatever.

My definition of an antenna is a matching transformer which matched
the output impedance of a transmitter, with that of free space (377
ohms). Convention has it to name the antenna after the designer. In
this case, Shintaro Uda was the student assistant who designed the
antenna, while Hidetsugu Yagi was his university instructor. Uda
published a paper on the design in Japanese, which nobody seemed to
have noticed. A few years later, Yagi translated the paper into
English, which finally got some attention. Its publication resulted
in the antenna being called a Yagi antenna by the American press. Yagi
repeatedly reminded everyone that it was Uda who had designed the
antenna, and deserved the credit. However, the best that could be
done was the Yagi-Uda contraction, which is awkward and backwards.

http://what-is-what.com/what_is/Yagi_Uda_antenna.html
"Despite the fact that Hidetsugu Yagi never took credit for
the antenna's design, it was his name that the American press
used to refer to the concept."

http://www.radiocomms.com.au/content/industry/article/yagi-the-man-behind-the-antenna-647231587
"The technology is all down to Prof Hidetsugu Yagi and his
assistant Shintaro Uda; more to Uda than Yagi, in fact, so
strictly speaking the design should be known as the Uda antenna,
or at least Yagi-Uda."

Incidentally, I have an FM broadcast Yagi-Uda antenna on my roof that
was made by the Yagi-Uda Antenna Company (or something like that).
I'll see if I can find the documentation and post a copy.

Both of these pages were interesting, but hard to read. I don't get why
some pages use a light grey text. I suppose some don't have a problem
reading that, but I do, a *lot*. The other page intentionally added a
shadow to the text, not just the headings or links, making that page
even harder for me to read. I really don't get that either.

I found a few more pages on Yagi-Uda antennas and some derivatives. One
describes how to build a Quagi antenna where the driven element and the
reflector are loops. Seems that works pretty well getting similar
numbers to Yagi type antennas with more directors.

What I really need in an antenna, is something I can add to the ubiquiti
nanostation m900 loco I am using for Internet access. The internal
antenna is only 7.5 dBi. I see a Yagi which is 13 dBi but it seems to
be out of date. The current model is very fancy and is over $200. The
other one is only $33.

--

Rick

What's In a Name -- Of My Antenna?
 

In message , rickman
writes



Both of these pages were interesting, but hard to read. I don't get
why some pages use a light grey text. I suppose some don't have a
problem reading that, but I do, a *lot*.

+1

It's plain stupid. Perhaps they think that they are saving 'ink'! A
quick fix is to highlight the offending text.




--
Ian

What's In a Name -- Of My Antenna?
 

On 3/26/2016 4:20 AM, Ian Jackson wrote:
In message , rickman writes



Both of these pages were interesting, but hard to read. I don't get
why some pages use a light grey text. I suppose some don't have a
problem reading that, but I do, a *lot*.

+1

It's plain stupid. Perhaps they think that they are saving 'ink'! A
quick fix is to highlight the offending text.

Sometimes that is worse than the original, improves contrast, but horrid
to read still. It does nothing for the shadowed text. That one is
truly bizarre. I think it is a "style" thing. They are trying to be
trendy.

--

Rick

What's In a Name -- Of My Antenna?
 

On Sat, 26 Mar 2016 02:17:21 -0400, rickman wrote:

Both of these pages were interesting, but hard to read. I don't get why
some pages use a light grey text. I suppose some don't have a problem
reading that, but I do, a *lot*. The other page intentionally added a
shadow to the text, not just the headings or links, making that page
even harder for me to read. I really don't get that either.

If you're using Firefox, click on the "reader view" icon.
https://support.mozilla.org/en-US/kb/firefox-reader-view-clutter-free-web-pages
There are similar features and plug-ins for other browsers.

I see all too much of the "gray text" problem that inspired such
things as "reader view". I agree, it sucks. It's the result of some
of the really bad style sheets that are found in many CMS (content
management system) web page creations. It's main benefit is that it
emphasizes the advertising. It also holds your attention longer so
that you stay on the web page longer. I can bore you with details on
how this works in advertising if you're interested.

I found a few more pages on Yagi-Uda antennas and some derivatives. One
describes how to build a Quagi antenna where the driven element and the
reflector are loops. Seems that works pretty well getting similar
numbers to Yagi type antennas with more directors.

Yep. A quagi is a square loop element. The big advantage of quagi
and loop yagi antennas is that they squeeze a few more dB of gain
(about 2-3dB) with the same boom length as a conventional yagi. That's
not a trivial amount when you consider that in order to get 3dB more
gain out of a yagi, the boom has to be twice as long.

What I really need in an antenna, is something I can add to the ubiquiti
nanostation m900 loco I am using for Internet access. The internal
antenna is only 7.5 dBi. I see a Yagi which is 13 dBi but it seems to
be out of date. The current model is very fancy and is over $200. The
other one is only $33.

I'm involved with a bunch of 900 MHz ham radio repeaters and had a
fair amount of experience with 900 MHz. I don't like yagi antennas
for 900 or 2.4GHz. I prefer patch or panel antennas. However, if you
must buy a yagi, I suggest something by Antennex or something resold
by Laird. By the time you get to 13 or 14dBi gain, the bandwidth of a
yagi becomes sufficiently narrow that you'll loose gain at the band
edges. Since your radio needs to hop from 902-928Mhz, you'll need an
antenna that's fairly flat across the entire range. Just keep your
eye on the VSWR vs Freq graphs to avoid this problem.
http://www.lairdtech.com/product-categories/antennas/yagis
http://www.l-com.com/wireless-antenna-900-mhz-yagi-antennas

Gotta run...
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

What's In a Name -- Of My Antenna?
 

On 3/26/2016 1:14 PM, Jeff Liebermann wrote:
On Sat, 26 Mar 2016 02:17:21 -0400, rickman wrote:

Both of these pages were interesting, but hard to read. I don't get why
some pages use a light grey text. I suppose some don't have a problem
reading that, but I do, a *lot*. The other page intentionally added a
shadow to the text, not just the headings or links, making that page
even harder for me to read. I really don't get that either.

If you're using Firefox, click on the "reader view" icon.
https://support.mozilla.org/en-US/kb/firefox-reader-view-clutter-free-web-pages
There are similar features and plug-ins for other browsers.

I see all too much of the "gray text" problem that inspired such
things as "reader view". I agree, it sucks. It's the result of some
of the really bad style sheets that are found in many CMS (content
management system) web page creations. It's main benefit is that it
emphasizes the advertising. It also holds your attention longer so
that you stay on the web page longer. I can bore you with details on
how this works in advertising if you're interested.

I found a few more pages on Yagi-Uda antennas and some derivatives. One
describes how to build a Quagi antenna where the driven element and the
reflector are loops. Seems that works pretty well getting similar
numbers to Yagi type antennas with more directors.

Yep. A quagi is a square loop element. The big advantage of quagi
and loop yagi antennas is that they squeeze a few more dB of gain
(about 2-3dB) with the same boom length as a conventional yagi. That's
not a trivial amount when you consider that in order to get 3dB more
gain out of a yagi, the boom has to be twice as long.

What I really need in an antenna, is something I can add to the ubiquiti
nanostation m900 loco I am using for Internet access. The internal
antenna is only 7.5 dBi. I see a Yagi which is 13 dBi but it seems to
be out of date. The current model is very fancy and is over $200. The
other one is only $33.

I'm involved with a bunch of 900 MHz ham radio repeaters and had a
fair amount of experience with 900 MHz. I don't like yagi antennas
for 900 or 2.4GHz. I prefer patch or panel antennas. However, if you
must buy a yagi, I suggest something by Antennex or something resold
by Laird. By the time you get to 13 or 14dBi gain, the bandwidth of a
yagi becomes sufficiently narrow that you'll loose gain at the band
edges. Since your radio needs to hop from 902-928Mhz, you'll need an
antenna that's fairly flat across the entire range. Just keep your
eye on the VSWR vs Freq graphs to avoid this problem.
http://www.lairdtech.com/product-categories/antennas/yagis
http://www.l-com.com/wireless-antenna-900-mhz-yagi-antennas

The datasheet for the NanoStationlocoM9 which seems to be the newer
version of what I have has a return loss graph for the internal antenna.
This seems to show a range centered on about 917 MHz and not too wide.
It says the frequencies used are 902 to 928 MHz.

I looked at the highest gain antennas from each of these two and neither
supplies VSWR graphs. The Laird PC9013N has 13 elements and says freq
range is 902 to 928 MHz which seems to roughly match the internal antenna.

The L-com model HG914YE with 14 elements says it works from 824 to 960
MHz. It claims a 1.5:1 VSWR "average" which I guess means something,
but I'm not sure what. This unit has 14 dBi of gain while the Laird is
13 dBi. I'm thinking 1 dB is not so much. The Laird seems to be well
over $100 and the L-com around $50 with free shipping. I'll also need
an N to SMA pigtail. First I need to ask my provider. He may have to
twiddle something in the box to enable the antenna input.

BTW, one of these antennas says the directors are welded to the boom. I
always thought the elements were insulated from each other and the boom.
I recall seeing insulation on old TV antennas, was that just to
prevent corrosion or something?

--

Rick

What's In a Name -- Of My Antenna?
 

On 3/26/2016 1:14 PM, Jeff Liebermann wrote:
On Sat, 26 Mar 2016 02:17:21 -0400, rickman wrote:

Both of these pages were interesting, but hard to read. I don't get why
some pages use a light grey text. I suppose some don't have a problem
reading that, but I do, a *lot*. The other page intentionally added a
shadow to the text, not just the headings or links, making that page
even harder for me to read. I really don't get that either.

If you're using Firefox, click on the "reader view" icon.
https://support.mozilla.org/en-US/kb/firefox-reader-view-clutter-free-web-pages
There are similar features and plug-ins for other browsers.

I just gave this a try. It completely changes the page formatting. It
doesn't seem to work with just any page. Not sure about the
capabilities, I'll have to play with it. Thanks

--

Rick

What's In a Name -- Of My Antenna?
 

In message , rickman
writes
On 3/26/2016 1:14 PM, Jeff Liebermann wrote:
On Sat, 26 Mar 2016 02:17:21 -0400, rickman wrote:

Both of these pages were interesting, but hard to read. I don't get why
some pages use a light grey text. I suppose some don't have a problem
reading that, but I do, a *lot*. The other page intentionally added a
shadow to the text, not just the headings or links, making that page
even harder for me to read. I really don't get that either.

If you're using Firefox, click on the "reader view" icon.

https://support.mozilla.org/en-US/kb...-clutter-free-
web-pages
There are similar features and plug-ins for other browsers.

I just gave this a try. It completely changes the page formatting. It
doesn't seem to work with just any page. Not sure about the
capabilities, I'll have to play with it. Thanks

I hadn't realised that there WAS a "reader view". Thanks for the info!
--
Ian

What's In a Name -- Of My Antenna?
 

On Sat, 26 Mar 2016 14:08:12 -0400, rickman wrote:

The datasheet for the NanoStationlocoM9 which seems to be the newer
version of what I have has a return loss graph for the internal antenna.
This seems to show a range centered on about 917 MHz and not too wide.
It says the frequencies used are 902 to 928 MHz.

Unless Ubiquiti is doing something odd, if they use FHSS (frequency
hopping spread spectrum), the radio must hop all 83 channels (in 1 MHz
increments) within some interval that I'm too lazy to excavate from
FCC Part 15. In effect, you'll see it hop the entire allocated
frequency range.

One source of confusion is whether an antenna has to TUNE over a
frequency range, or whether it has to OPERATE over a frequency range.
It's possible to find a narrow band FM 900 MHz antenna that will tune
the desired range, but once tuned, has a much smaller operating
bandwidth. High gain Yagi and big gain patch/panel antennas are
potential problems.

I looked at the highest gain antennas from each of these two and neither
supplies VSWR graphs. The Laird PC9013N has 13 elements and says freq
range is 902 to 928 MHz which seems to roughly match the internal antenna.

The L-com model HG914YE with 14 elements says it works from 824 to 960
MHz. It claims a 1.5:1 VSWR "average" which I guess means something,
but I'm not sure what.

Average is not the usual term. I would have no problem with 1.5:1
maximum VSWR, but average sounds like they're hiding a problem.

This unit has 14 dBi of gain while the Laird is
13 dBi.

Many of the gain plots are simulations and are not the result of field
tests or anechoic chamber tests. It's fairly easy to recognize the
difference. The real tests show lower numbers and look far from idea.
The simulations look too good.

I'm thinking 1 dB is not so much. The Laird seems to be well
over $100 and the L-com around $50 with free shipping. I'll also need
an N to SMA pigtail. First I need to ask my provider. He may have to
twiddle something in the box to enable the antenna input.

Ask your WISP what kind of antenna he recommends. I doubt that this
is the first higher gain antenna that he's installed.

I still recommend using a panel antenna. I have a few in the office,
but they're circular polarization for near field devices and probably
won't work for you. Start he
https://www.google.com/#q=900+mhz+panel+antenna
Anything over about 10dBi gain should be sufficient.

BTW, one of these antennas says the directors are welded to the boom.

Yes. Good idea if you want it to survive. All of the Laird (Antenex)
Yagi's that I've used were welded and had rounded ends to improve the
bandwidth. They're more expensive than bolt together Yagi's but I
think it's worth it for mountain top use, where I have to pay an
expensive certified tower climber to deal with any damage. However,
for the average consumer, it's probably overkill.

I always thought the elements were insulated from each other and the boom.
I recall seeing insulation on old TV antennas, was that just to
prevent corrosion or something?

No. It makes the TV antenna easy to ship in a smaller box. If TV
antennas were welded and shipped ready to install, they would be huge,
and the shipping would be seriously expensive.

The elements of a Yagi do not need to insulated from the boom.
However, the length of the elements is affected by the boom. The RF
path goes around the boom in the welded design requiring 1/2 the
circumference of the boom to be added to the element length
calculation.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

What's In a Name -- Of My Antenna?
 

On Sat, 26 Mar 2016 14:13:01 -0400, rickman wrote:

On 3/26/2016 1:14 PM, Jeff Liebermann wrote:
On Sat, 26 Mar 2016 02:17:21 -0400, rickman wrote:

Both of these pages were interesting, but hard to read. I don't get why
some pages use a light grey text. I suppose some don't have a problem
reading that, but I do, a *lot*. The other page intentionally added a
shadow to the text, not just the headings or links, making that page
even harder for me to read. I really don't get that either.

If you're using Firefox, click on the "reader view" icon.
https://support.mozilla.org/en-US/kb/firefox-reader-view-clutter-free-web-pages
There are similar features and plug-ins for other browsers.

I just gave this a try. It completely changes the page formatting. It
doesn't seem to work with just any page. Not sure about the
capabilities, I'll have to play with it. Thanks

This might be closer to what you're looking for.
https://addons.mozilla.org/en-US/firefox/addon/blacken/
All it does is darken the text, without mangling the formatting.

I just tried it and it does work as advertised. It initially didn't
make text as dark as I would like, so I tweaked the settings.

There are quite a few settings under:
Tools - Add-ons - Extensions
where the defaults are not particularly ideal. It has an "automatic"
mode, which seems to recognize problem web pages with nearly invisible
text. Blacken can be controlled with the "B" icon that was added to
the Firefox toolbar. Try the "help" under the "B" icon for some
details and capabilities.

Here's the previous faded URL again for testing:
http://www.radiocomms.com.au/content/industry/article/yagi-the-man-behind-the-antenna-647231587

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

What's In a Name -- Of My Antenna?
 

On 3/27/2016 5:12 PM, Jeff Liebermann wrote:
On Sat, 26 Mar 2016 14:08:12 -0400, rickman wrote:

The datasheet for the NanoStationlocoM9 which seems to be the newer
version of what I have has a return loss graph for the internal antenna.
This seems to show a range centered on about 917 MHz and not too wide.
It says the frequencies used are 902 to 928 MHz.

Unless Ubiquiti is doing something odd, if they use FHSS (frequency
hopping spread spectrum), the radio must hop all 83 channels (in 1 MHz
increments) within some interval that I'm too lazy to excavate from
FCC Part 15. In effect, you'll see it hop the entire allocated
frequency range.

One source of confusion is whether an antenna has to TUNE over a
frequency range, or whether it has to OPERATE over a frequency range.
It's possible to find a narrow band FM 900 MHz antenna that will tune
the desired range, but once tuned, has a much smaller operating
bandwidth. High gain Yagi and big gain patch/panel antennas are
potential problems.

I'm talking about the antenna built into a working unit. You seem to be
discussing the state of the art in general.


I looked at the highest gain antennas from each of these two and neither
supplies VSWR graphs. The Laird PC9013N has 13 elements and says freq
range is 902 to 928 MHz which seems to roughly match the internal antenna.

The L-com model HG914YE with 14 elements says it works from 824 to 960
MHz. It claims a 1.5:1 VSWR "average" which I guess means something,
but I'm not sure what.

Average is not the usual term. I would have no problem with 1.5:1
maximum VSWR, but average sounds like they're hiding a problem.

This unit has 14 dBi of gain while the Laird is
13 dBi.

Many of the gain plots are simulations and are not the result of field
tests or anechoic chamber tests. It's fairly easy to recognize the
difference. The real tests show lower numbers and look far from idea.
The simulations look too good.

I'm thinking 1 dB is not so much. The Laird seems to be well
over $100 and the L-com around $50 with free shipping. I'll also need
an N to SMA pigtail. First I need to ask my provider. He may have to
twiddle something in the box to enable the antenna input.

Ask your WISP what kind of antenna he recommends. I doubt that this
is the first higher gain antenna that he's installed.

Bet it *is*! In fact, I bet the only high gain antenna he has installed
was the point to point link to connect his antennas. He likely doesn't
do the work himself since that requires climbing towers and likely a
crane. Do they carry the components up by hand? I can't imagine they
would.

He said something about adding a tower in a few months which will add
bandwidth to the system. But he has always said my air link was
marginal when compared to my neighbors, at this point some 6 dB worse.
I'd like to fix that. I know none of my nearest neighbors who get his
service are even in the area. It is on a lake and one guy is only here
on weekends in the summer and the other guy is only here a *few*
weekends in the summer. He does have cameras that are accessed over the
Internet, so they might use bandwidth all the time, don't know, maybe
only when someone wants to look. He uses some third party service to
make the connection. They might be recording all the time.


I still recommend using a panel antenna. I have a few in the office,
but they're circular polarization for near field devices and probably
won't work for you. Start he
https://www.google.com/#q=900+mhz+panel+antenna
Anything over about 10dBi gain should be sufficient.

The existing internal antenna is 7 dBi. I can't see going to the
trouble of using an external antenna to get another 3 dB. I did find a
couple of panel antennas that give 12.5 dB. They might be cheaper than
the Yagi I found at $70. One panel was $40, but out of stock.


BTW, one of these antennas says the directors are welded to the boom.

Yes. Good idea if you want it to survive. All of the Laird (Antenex)
Yagi's that I've used were welded and had rounded ends to improve the
bandwidth. They're more expensive than bolt together Yagi's but I
think it's worth it for mountain top use, where I have to pay an
expensive certified tower climber to deal with any damage. However,
for the average consumer, it's probably overkill.

I always thought the elements were insulated from each other and the boom.
I recall seeing insulation on old TV antennas, was that just to
prevent corrosion or something?

No. It makes the TV antenna easy to ship in a smaller box. If TV
antennas were welded and shipped ready to install, they would be huge,
and the shipping would be seriously expensive.

Making them collapsible doesn't require insulators. Each folding
element had a piece of what looked like card stock between the element
and the mounting point on the boom. Was that to prevent corrosion maybe?

I assume the active element is insulated, right?


The elements of a Yagi do not need to insulated from the boom.
However, the length of the elements is affected by the boom. The RF
path goes around the boom in the welded design requiring 1/2 the
circumference of the boom to be added to the element length
calculation.



--

Rick

What's In a Name -- Of My Antenna?
 

"rickman" wrote in message ...



What I really need in an antenna, is something I can add to the ubiquiti
nanostation m900 loco I am using for Internet access. The internal
antenna is only 7.5 dBi. I see a Yagi which is 13 dBi but it seems to
be out of date. The current model is very fancy and is over $200. The
other one is only $33.

--

Rick

================================================== ==

Consider the Browning antenna for 2.4 GHz.

http://www.walmart.com/ip/Browning-B...tenna/21188799

We're using them for a mesh network experiment. Mine came from Radio Shack
(online) for about that same price. I cannot recall the model number of
the ones I bought but the housing matches.

"Sal"
(KD6VKW)

What's In a Name -- Of My Antenna?
 

On Sun, 3 Apr 2016 15:37:40 -0700, "Sal M. O'Nella"
wrote:

Consider the Browning antenna for 2.4 GHz.
http://www.walmart.com/ip/Browning-B...tenna/21188799
We're using them for a mesh network experiment. Mine came from Radio Shack
(online) for about that same price. I cannot recall the model number of
the ones I bought but the housing matches.

His Ubiquiti Nanostation m900 Loco runs on 900MHz, not 2.4GHz.
Also, the 2 reviews above, of the Browning yagi both indicate that the
antenna fell apart when removed from the box.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

What's In a Name -- Of My Antenna?
 

"Sal M. O'Nella" wrote in message ...



"rickman" wrote in message ...



What I really need in an antenna, is something I can add to the ubiquiti
nanostation m900 loco I am using for Internet access. The internal
antenna is only 7.5 dBi. I see a Yagi which is 13 dBi but it seems to
be out of date. The current model is very fancy and is over $200. The
other one is only $33.

How about this one for $30

http://www.amazon.com/Yagi-WiFi-Ante...ilpage_o01_s00

What's In a Name -- Of My Antenna?
 

"Jeff Liebermann" wrote in message
...

On Sun, 3 Apr 2016 15:37:40 -0700, "Sal M. O'Nella"
wrote:

Consider the Browning antenna for 2.4 GHz.
http://www.walmart.com/ip/Browning-B...tenna/21188799
We're using them for a mesh network experiment. Mine came from Radio Shack
(online) for about that same price. I cannot recall the model number of
the ones I bought but the housing matches.

His Ubiquiti Nanostation m900 Loco runs on 900MHz, not 2.4GHz.
Also, the 2 reviews above, of the Browning yagi both indicate that the
antenna fell apart when removed from the box.
====================================

I'm sorry to hear the Browning antenna was a disappointment. Mine matches a
more expensive Wifi antenna and has proven durable.

Thanks for the correction regarding the frequencies. I missed that.

"Sal"
(KD6VKW)

What's In a Name -- Of My Antenna?
 

"Wayne" wrote in message ...



"Sal M. O'Nella" wrote in message ...



"rickman" wrote in message ...



What I really need in an antenna, is something I can add to the ubiquiti
nanostation m900 loco I am using for Internet access. The internal
antenna is only 7.5 dBi. I see a Yagi which is 13 dBi but it seems to
be out of date. The current model is very fancy and is over $200. The
other one is only $33.

How about this one for $30

http://www.amazon.com/Yagi-WiFi-Ante...ilpage_o01_s00

================================================
It looks like the one I bought that would not perform well for me at 2.4
GHz. I measured my directors, which should be close to (but slightly
shorter than) a half wavelength.

They measure 5 cm tip-to-tip but are NOT insulated from the boom, so add
another cm or so, making them effectively 6 cm long or half of a 12 cm
wavelength.

By the formula 300/wavelength in meters, 300/0.12 = 2500 MHz. It ought to
work -- so my problem is evidently somewhere else.

Sorry but I'm no help.

"Sal"

What's In a Name -- Of My Antenna?
 

On Sun, 10 Apr 2016 22:51:07 -0700, "Sal M. O'Nella"
wrote:

"Jeff Liebermann" wrote in message
.. .

On Sun, 3 Apr 2016 15:37:40 -0700, "Sal M. O'Nella"
wrote:

Consider the Browning antenna for 2.4 GHz.
http://www.walmart.com/ip/Browning-B...tenna/21188799
We're using them for a mesh network experiment. Mine came from Radio Shack
(online) for about that same price. I cannot recall the model number of
the ones I bought but the housing matches.

His Ubiquiti Nanostation m900 Loco runs on 900MHz, not 2.4GHz.
Also, the 2 reviews above, of the Browning yagi both indicate that the
antenna fell apart when removed from the box.
====================================

I'm sorry to hear the Browning antenna was a disappointment. Mine matches a
more expensive Wifi antenna and has proven durable.

I'm surprised that it worked for you. I could find no data other than
the claimed 15dBi gain for the Browning BR-6320. It's carried by many
dealers, but I could find no link to the original manufactory. I
guess I'm spoiled and find that specifications, graphs, and field
tests to be rather useful.

Also, I seem to have had bad luck with wi-fi yagi's. Here's an
analysis of the MFJ-1800 yagi, that demonstrates that it's really a
200 ohm antenna, not 50 ohms.
http://802.11junk.com/jeffl/antennas/mfj1800/index.html
Here's another loser I bought on eBay:
http://802.11junk.com/jeffl/crud/wi-fi-yagi-that-sucks.jpg

I've been under the impression that mesh networks require
omnidirectional antennas. Directional yagis can be used if you're
covering a perimeter, but then tend to limit the coverage area of the
mesh. Also, I gave a talk/rant on wi-fi mesh network issues and
problems to the local Linux user group. Here's my disorganized notes
and graphics:
http://802.11junk.com/jeffl/FLUG-talk-2015-02-28/
The fun part is when I demonstrated wireless throughput with and
without the mesh network, as simulated by a single wi-fi repeater.
This is on 5GHz direct (no mesh repeater) at about 60 mbits/sec
thruput:
http://802.11junk.com/jeffl/FLUG-talk-2015-02-28/802.1a%20direct.jpg
This is the same hardware as above, but through a Netgear WN3000RP(?)
repeater used as a mesh simulator at about 24 mbits/sec:
http://802.11junk.com/jeffl/FLUG-talk-2015-02-28/802.11gn%20through%20Netgear%20repeater.jpg
for a 60% loss in maximum thruput.

Good luck on your mesh network experiment.

Thanks for the correction regarding the frequencies. I missed that.
"Sal"
(KD6VKW)

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558