<cmk128@hotmail.com> wrote in message
news:1178413770.522672.190160@p77g2000hsh.googlegr oups.com...
| Hi
| I want to buy a wifi antenna for my 802.11g router, but the
| antenna will not amplify the signal, so why it works?
|
| thanks
| from Peter (cmk128@hotmail.com)
Climbing a ladder does not make your eyes stronger but does give you a
better view.
On May 5, 8:09 pm, cmk...@hotmail.com wrote:
> Hi
> I want to buy a wifi antenna for my 802.11g router, but the
> antenna will not amplify the signal, so why it works?
>
> thanks
> from Peter (cmk...@hotmail.com)
Maybe because the antenna doesn't come with an amplifier? If it does,
try plugging it in.
All physically realizable antennas have gain, ask specific more
question as to why work.
I always figured if God didn't like antenna gain, He wouldn't have
created earlobes.
>I want to buy a wifi antenna for my 802.11g router, but the
>antenna will not amplify the signal, so why it works?
Antennas do not generate or amplify anything. What they do is
redirect signal that would normally go in unwanted directions, to the
direction that you want the signal to go. A tolerable analogy is a
garden hose nozzle. You can set the nozzle to a fine wide spray, or
to a pointed narrow stream. The volume of water delivered in both
cases is the same and is the transmit power.
As the stream gets narrower and narrower, it will go farther and
farther, which is the whole idea. How much farther is a function of
this directionality or gain. In RF terms:
+6dB = 2 times as far
+8dB = 2.5 times as far
+12dB = 4 times as far
+24dB = 16 times as far
You might find the FAQ for alt.internet.wireless worth skimming:
<http://wireless.wikia.com/wiki/Wi-Fi>
Another reason to install an external antenna is that your RV probably
has aluminum sides and foil backed insulation in the walls. No RF is
going to penetrate that much metal. So, you're only alternative for
getting a decent connection at the RV park, truck stop, or coffee
shop, from the RV, is with an external antenna. Highly directional
antennas are also very useful for eliminating interference from nearby
users and systems.
>The garden hose analogy is a good one, Jeff! I'll have to remember
>that one.
>Pete
Thanks, but like all analogies, it somewhat fails in the end. The
common garden hose cylindrical nozzle changes orifice area with
different spray patterns. Therefore, the flow rate (tx power output)
will be larger with a stream than with a spray. I got into a debate
over the issue many years ago. Rather than do the calculations, I
convinced the local grade skool brats to do a quick measurement. Well,
it wasn't so quick and bribes were required for motivation, but the
experiment was successful. I had them build a really crude paddle and
counter flow meter with all the technology that could be borrowed from
the neighborhood landscape contractor. I have photos somewhere. There
was something like 50% more flow with the nozzle in stream than in
spray. However, when we tried different style nozzles, there were
some substantial differences. The more expensive nozzles, that
resemble a fire hoze nozzle with a handle, have almost a constant flow
rate with any pattern. Despite being not exactly perfect, it's good
enough for explaining how antennas operate.
> Hi
> I want to buy a wifi antenna for my 802.11g router, but the
> antenna will not amplify the signal, so why it works?
>
> thanks
> from Peter (cmk128@hotmail.com)
>
Hi,
Ever heard about antenna gain, radiation angle, pattern(horiz. vs vert.)
as an example?
Antenna theory is very complex subject which needs lot of real world
experiments.
> <cmk128@hotmail.com> wrote in message
> news:1178413770.522672.190160@p77g2000hsh.googlegr oups.com...
>
>>Hi
>> I want to buy a wifi antenna for my 802.11g router, but the
>>antenna will not amplify the signal, so why it works?
>
>
> Antenna has gain. Think of it as concentrating the energy.
> Some antennas have unity gain, and by adding elements to the antenna you can
> increase its gain.
OK, you guys said the antenna concentrating the energy to a narrow
direction. But how does the omni wifi antenna work? why it has a gain?
I connect my linksys 802.11g router to a TV antenna (like this one http://www.granbytv.com/3671__Antenna.jpg) by using a normal wire. The
wire is just a very normal copper wire. The result is : i don't see
the signal become stronger. I think i need a dish antenna. Any idea?
<cmk128@hotmail.com> wrote in message
news:1178444581.427100.317690@p77g2000hsh.googlegr oups.com...
> OK, you guys said the antenna concentrating the energy to a narrow
> direction. But how does the omni wifi antenna work? why it has a gain?
>
> I connect my linksys 802.11g router to a TV antenna (like this one
> http://www.granbytv.com/3671__Antenna.jpg) by using a normal wire. The
> wire is just a very normal copper wire. The result is : i don't see
> the signal become stronger. I think i need a dish antenna. Any idea?
>
> thanks
> from Peter
>
Your TV antenna isn't resonant at the right frequency, the impendence is
mismatched, if you have an amplifier in the TV antenna line it may be
filtering out the WiFi frequency and a whole lot of other possibilities.
Bottom line is that your TV antenna isn't designed to work for WiFi.
Omni directional antennas can also have gain. A "5/8 wave length" vertical
antenna has gain, but is not directional in the sense "concentrating energy
in a narrow direction".
There are lots of books out there on antenna theory and antenna
construction, but you probably don't want to go into the subject far enough
to understand what does what and why. Many variables have to be considered
such as wavelength, impedance, reactance, height above ground, and many
others.
A simple WiFi antenna mounted on top of your RV may well do what you want to
do.
Ron Recer wrote:
> <cmk128@hotmail.com> wrote in message
> news:1178444581.427100.317690@p77g2000hsh.googlegr oups.com...
>> OK, you guys said the antenna concentrating the energy to a narrow
>> direction. But how does the omni wifi antenna work? why it has a gain?
>>
>> I connect my linksys 802.11g router to a TV antenna (like this one
>> http://www.granbytv.com/3671__Antenna.jpg) by using a normal wire. The
>> wire is just a very normal copper wire. The result is : i don't see
>> the signal become stronger. I think i need a dish antenna. Any idea?
>>
>> thanks
>> from Peter
>>
> Your TV antenna isn't resonant at the right frequency, the impendence is
> mismatched, if you have an amplifier in the TV antenna line it may be
> filtering out the WiFi frequency and a whole lot of other possibilities.
> Bottom line is that your TV antenna isn't designed to work for WiFi.
>
> Omni directional antennas can also have gain. A "5/8 wave length" vertical
> antenna has gain, but is not directional in the sense "concentrating energy
> in a narrow direction".
>
> http://www.qsl.net/w4sat/five8th.htm
>
> There are lots of books out there on antenna theory and antenna
> construction, but you probably don't want to go into the subject far enough
> to understand what does what and why. Many variables have to be considered
> such as wavelength, impedance, reactance, height above ground, and many
> others.
>
> A simple WiFi antenna mounted on top of your RV may well do what you want to
> do.
>
> Ron
>
>
>OK, you guys said the antenna concentrating the energy to a narrow
>direction. But how does the omni wifi antenna work? why it has a gain?
The garden hose nozzle analogy won't work for an omni. For that, I
offer the rubber inner tube analogy. The antenna pattern for an
omnidirectional antenna looks much like a donut (torus). A relatively
low gain antenna, such as the 2dBi rubber ducky commonly found on
wireless routers, looks like a "fat" donut. However, if you apply
vertical pressure to the donut, the donut will become widers as it
becomes flatter. What we've done is trade signal in the up and down
direction, for gain in the horizontal. Push hard enough, and the
donut becomes almost a flat pancake, with lots of horizontal gain, and
almost no signal above or below horizontal.
Note that the volume of the donut (torus) remains the same no matter
how flat you adjust the pattern. This volume is the transmit power
which remains unchanged.
>I connect my linksys 802.11g router to a TV antenna (like this one
>http://www.granbytv.com/3671__Antenna.jpg) by using a normal wire. The
>wire is just a very normal copper wire. The result is : i don't see
>the signal become stronger. I think i need a dish antenna. Any idea?
Give up while you're still sane. You need to deal with the basics.
Most antennas are resonant or optimized for a specific frequency or
frequency band. TV antennas are quite broadband but generally give up
at the high end of the UHF band (about 900MHz). Above this frequency,
they have no gain. Since the TV antenna is also off resonance, it
will reflect most of the power back to your unspecified model Linksys
router.
If you have some interest in building your own Wi-Fi antenna, there
are a substantial number of construction articles available. For RV
use, I suggest a biquad, or coffee can directional antenna. A dish is
usually too big. Omni antennas tend to be a problem because by the
time you get sufficient gain to be useful, the differences in vertical
elevation between the RV and the access point will cause access point
to be outside of the antenna pattern. RV parks also tend to be
infested with trees, which block the signal. You'll need all the gain
you can get to penetrate the foliage.
"Dana" <raff242@yahoo.com> hath wroth:
>"Jeff Liebermann" <jeffl@comix.santa-cruz.ca.us> wrote in message
>> Give up while you're still sane.
>I missed that the first time. I did not notice that he was trying to connect
>a tv antenna to his router. Then you are correct, it will not be of the
>proper impedance, frequency, etc.
Well, there's another problem. He's connecting it to a wireless
router instead of a wireless client, or wireless ethernet bridge. Only
a few wireless routers and access points have a "client mode"
available, which can be used to connect to a remote hot spot. It
would be interesting to know what he's trying to accomplish.
Perhaps it might be best to start over and supply the basics necessary
to answer any technical question:
1. What are you trying to accomplish?
2. What do you have to work with? (hardware and software names and
versions).
3. What have you done so far and what happened? (error messages,
problems, complications).
Drivel: I modeled Radio Shack yagi and log periodic TV antennas to
see how well it worked. On some channels, the yagi had more gain
pointed backwards than forwards. On some channels, one could do
better with a pair of rabbit ears. The log periodic is quite good for
bandwidth, but has little gain (about 4dBi). Bigger also isn't
better. However, building a functional antenna that works from 54 to
800MHz (4 octaves) bandwidth is not easy. I don't think I could do
much better.
"Dana" <raff242@yahoo.com> wrote
>
> "Will Sill" <will@epix.cnet> wrote
>>
>> Excuse me for interrupting, but antenna gain figures are totally
>> meaningless UNLESS they are given with respect to some known
>> reference. For example, expressed as "dBd" (with respect to a
>> dipole).
>
> dBi is the typical reference used for antenna and most on the newsgroup is
> aware of that.
That may well be true, but the OP is a nitwit who cross posted the question
to a "non-antenna" group, so many of the people reading your responses may
not have your awareness of antenna related issues.
<cmk128@hotmail.com> wrote in message
news:1178413770.522672.190160@p77g2000hsh.googlegr oups.com...
> Hi
> I want to buy a wifi antenna for my 802.11g router, but the
> antenna will not amplify the signal, so why it works?
Antenna has gain. Think of it as concentrating the energy.
Some antennas have unity gain, and by adding elements to the antenna you can
increase its gain.
"bruce" <bruce.snell@gmail.com> wrote in message
news:463e4337$0$3049$c3e8da3@news.astraweb.com...
>
> "Dana" <raff242@yahoo.com> wrote
>>
>> "Will Sill" <will@epix.cnet> wrote
>>>
>>> Excuse me for interrupting, but antenna gain figures are totally
>>> meaningless UNLESS they are given with respect to some known
>>> reference. For example, expressed as "dBd" (with respect to a
>>> dipole).
>>
>> dBi is the typical reference used for antenna and most on the newsgroup
>> is aware of that.
>
> That may well be true, but the OP is a nitwit who cross posted the
> question to a "non-antenna" group, so many of the people reading your
> responses may not have your awareness of antenna related issues.
>
> Bruce
>
It doesn't really matter, most of those reading it here probably don't know
what a dipole or isotropic source is anyway.
On 5¤ë6¤é, ¤U¤È11®É05¤À, "Ron Recer" <r...@aol.com> wrote:
> <cmk...@hotmail.com> wrote in message
>
> news:1178444581.427100.317690@p77g2000hsh.googlegr oups.com...> OK, you guys said the antenna concentrating the energy to a narrow
> > direction. But how does the omni wifi antenna work? why it has a gain?
>
> > I connect my linksys 802.11g router to a TV antenna (like this one
> >http://www.granbytv.com/3671__Antenna.jpg) by using a normal wire. The
> > wire is just a very normal copper wire. The result is : i don't see
> > the signal become stronger. I think i need a dish antenna. Any idea?
>
> > thanks
> > from Peter
>
> Your TV antenna isn't resonant at the right frequency, the impendence is
> mismatched, if you have an amplifier in the TV antenna line it may be
> filtering out the WiFi frequency and a whole lot of other possibilities.
> Bottom line is that your TV antenna isn't designed to work for WiFi.
>
> Omni directional antennas can also have gain. A "5/8 wave length" vertical
> antenna has gain, but is not directional in the sense "concentrating energy
> in a narrow direction".
>
> http://www.qsl.net/w4sat/five8th.htm
>
> There are lots of books out there on antenna theory and antenna
> construction, but you probably don't want to go into the subject far enough
> to understand what does what and why. Many variables have to be considered
> such as wavelength, impedance, reactance, height above ground, and many
> others.
>
> A simple WiFi antenna mounted on top of your RV may well do what you wantto
> do.
>
> Ron
No , my TV antenna is just a piece of metal. No electronic component
inside. This experience told me if i plug my router antenna wire to a
metal, it will enlarge the signal
thanks
from Peter
<cmk128@hotmail.com> wrote in message
news:1178444581.427100.317690@p77g2000hsh.googlegr oups.com...
> OK, you guys said the antenna concentrating the energy to a narrow
> direction. But how does the omni wifi antenna work? why it has a gain?
Because of the way the antenna is constructed.
You would have elements contstructed in the antenna in such a way they add
constructively to the signal, hence giving gain.
This is a very high level over view. Do a google on Antenna design to get
more detail.
>
> I connect my linksys 802.11g router to a TV antenna (like this one
> http://www.granbytv.com/3671__Antenna.jpg) by using a normal wire. The
> wire is just a very normal copper wire. The result is : i don't see
> the signal become stronger. I think i need a dish antenna. Any idea?
While using a dish antenna does have higher gain than an omni, it also
becomes more directional, hence you have to point the antenna towards the
transmitting device.
>
> thanks
> from Peter
>
"Jeff Liebermann" <jeffl@comix.santa-cruz.ca.us> wrote in message
news:q9tr33tfct96vishk1u3p11udkglsfi9s6@4ax.com...
> cmk128@hotmail.com hath wroth:
>
>>OK, you guys said the antenna concentrating the energy to a narrow
>>direction. But how does the omni wifi antenna work? why it has a gain?
>
> The garden hose nozzle analogy won't work for an omni. For that, I
> offer the rubber inner tube analogy. The antenna pattern for an
> omnidirectional antenna looks much like a donut (torus). A relatively
> low gain antenna, such as the 2dBi rubber ducky commonly found on
> wireless routers, looks like a "fat" donut. However, if you apply
> vertical pressure to the donut, the donut will become widers as it
> becomes flatter. What we've done is trade signal in the up and down
> direction, for gain in the horizontal. Push hard enough, and the
> donut becomes almost a flat pancake, with lots of horizontal gain, and
> almost no signal above or below horizontal.
>
> Note that the volume of the donut (torus) remains the same no matter
> how flat you adjust the pattern. This volume is the transmit power
> which remains unchanged.
>
>>I connect my linksys 802.11g router to a TV antenna (like this one
>>http://www.granbytv.com/3671__Antenna.jpg) by using a normal wire. The
>>wire is just a very normal copper wire. The result is : i don't see
>>the signal become stronger. I think i need a dish antenna. Any idea?
>
> Give up while you're still sane.
I missed that the first time. I did not notice that he was trying to connect
a tv antenna to his router. Then you are correct, it will not be of the
proper impedance, frequency, etc.
"Jeff Liebermann" <jeffl@comix.santa-cruz.ca.us> wrote in message
news:advr33lo80vnli5jitqdd46gqvv76v2ppa@4ax.com...
> "Dana" <raff242@yahoo.com> hath wroth:
>>"Jeff Liebermann" <jeffl@comix.santa-cruz.ca.us> wrote in message
>>> Give up while you're still sane.
>
>>I missed that the first time. I did not notice that he was trying to
>>connect
>>a tv antenna to his router. Then you are correct, it will not be of the
>>proper impedance, frequency, etc.
>
> Well, there's another problem. He's connecting it to a wireless
> router instead of a wireless client, or wireless ethernet bridge. Only
> a few wireless routers and access points have a "client mode"
> available, which can be used to connect to a remote hot spot. It
> would be interesting to know what he's trying to accomplish.
Well this is what keeps people who know with work.
I also do a lot of free consulting, and assistance, like replying to
questions to newsgroups and boards.
>
> Perhaps it might be best to start over and supply the basics necessary
> to answer any technical question:
> 1. What are you trying to accomplish?
> 2. What do you have to work with? (hardware and software names and
> versions).
> 3. What have you done so far and what happened? (error messages,
> problems, complications).
>
> Drivel: I modeled Radio Shack yagi and log periodic TV antennas to
> see how well it worked. On some channels, the yagi had more gain
> pointed backwards than forwards. On some channels, one could do
> better with a pair of rabbit ears. The log periodic is quite good for
> bandwidth, but has little gain (about 4dBi). Bigger also isn't
> better. However, building a functional antenna that works from 54 to
> 800MHz (4 octaves) bandwidth is not easy. I don't think I could do
> much better.
>
> --
> Jeff Liebermann jeffl@comix.santa-cruz.ca.us
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060 http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558
"Will Sill" <will@epix.cnet> wrote in message
news:cu1s33972o7r8fhdl5gce3ei8g8kdc6cbq@4ax.com...
>I see where "Ron Recer" <ron48@aol.com> contributed:
>
>>Omni directional antennas can also have gain. A "5/8 wave length"
>>vertical
>>antenna has gain, but is not directional in the sense "concentrating
>>energy
>>in a narrow direction".
>
> Excuse me for interrupting, but antenna gain figures are totally
> meaningless UNLESS they are given with respect to some known
> reference. For example, expressed as "dBd" (with respect to a
> dipole).
dBi is the typical reference used for antenna and most on the newsgroup is
aware of that.
For me, light works as a better analogy for radio signals than
water.
You can have a candle, that will light the whole room dimly.
If you put a nice shiny reflector on it, you can concentrate that
candle in one direction and get more light where you want it, though
the candle itself is no brighter.
If you take a magnifying glass to it, you can also concentrate and
focus the light to make it quite a bit brighter, but in a very narrow
direction only.
OK. Jeff, get out your analogy bashing hammer! (is that an analogy
or a simile?).
>For me, light works as a better analogy for radio signals than
>water.
Yeah, but water is more fun for live demonstrations.
>You can have a candle, that will light the whole room dimly.
Sure, as long as you don't set off the smoke detector.
>If you put a nice shiny reflector on it, you can concentrate that
>candle in one direction and get more light where you want it, though
>the candle itself is no brighter.
Good analogy.
>If you take a magnifying glass to it, you can also concentrate and
>focus the light to make it quite a bit brighter, but in a very narrow
>direction only.
Also good analogy.
>OK. Jeff, get out your analogy bashing hammer! (is that an analogy
>or a simile?).
The parts that you mentioned are quite good analogies. After all,
light and RF are both electromagnetic phenomenon.
Where the light versus 2.4GHz analogy falls apart is in fringing,
dispersion, and edge effects. The Fresnel Zone for light is almost
zilch and can usually be ignored. You can't do that for 2.4GHz.
Obstructions just outside of the line of sight act differently.
Dielectric lenses function at microwave frequencies, but are not
commonly understood by RV enthusiasts.
There's also a scaling problem. A reflector the size of a flashlight
reflector has quite a bit of gain at optical frequencies, but is next
to useless at 2.4GHz. Plenty more differences but I don't want to get
into quantum mechanics.
I use water instead of light because I've found that it prevents
interruptions and topic drift (like this posting). That applies to
both the dull and the bright people in the audience. The clueless
usually have some misconceptions and weird illusions about how light
and RF propagate. The "more metal makes a better antenna" rubbish in
this thread is typical. However, even the dimmest wit can see how a
water nozzle works, without all the preconceived notions. When using
water, I don't have to explain why a bigger antenna isn't necessarily
a better antenna.
The bright people in the audience are a bigger problem. They know
that there are plenty of situations where light works differently from
microwaves. That's not the point, but there's always someone with a
clue in the audience that brings up the differences. That creates an
instant diversion that rapidly progresses into irrelevant drivel. The
same person would not think of suggesting similar differences for a
water versus microwave analogy, because it's obvious to everyone
involved. So, my song and dance continues uninterrupted.
Therefore, water is a better analogy than light because it creates a
smaller catalyst for endless debate (and is far more fun for live
demonstrations).
Only $273.50 in hardcover from Powells. Ouch(tm).
Somewhat less on Amazon:
<http://www.amazon.com/Antennas-John-D-Kraus/dp/0072321032/ref=pd_bbs_sr_1/104-8779143-9959133?ie=UTF8&s=books&qid=1178588015&sr=8-1>
or used for as low as $35.
I have the original version, which is an excellent reference if you
happen to have an advanced degree in electronics or physics. The
current version is suppose to have dumbed down the math to something
students can understand and is apparently intended to be text book
instead of a reference guide. I haven't seen the new version.
If you really want to know how antennas work, the ARRL Antenna book is
informative, practical, understandable, fathomable, and relatively
cheap.
<http://www.arrl.org/catalog/8047/>
If you're into modeling antennas, there are quite a few good free or
cheap programs that can help beginners visualize how changes in
construction, design, and environment affect the various parameters.
My favorite is 4NEC2:
<http://home.ict.nl/~arivoors/>
It also includes a substantial number of examples.
Other programs are listed at:
<http://www.si-list.net/swindex.html>
<cmk128@hotmail.com> wrote in message
news:1178533360.813965.188970@y80g2000hsf.googlegr oups.com...
On 5¤ë6¤é, ¤U¤È11®É05¤À, "Ron Recer" <r...@aol.com> wrote:
> <cmk...@hotmail.com> wrote in message
>
> news:1178444581.427100.317690@p77g2000hsh.googlegr oups.com...> OK, you
> guys said the antenna concentrating the energy to a narrow
> > direction. But how does the omni wifi antenna work? why it has a gain?
>
> > I connect my linksys 802.11g router to a TV antenna (like this one
> >http://www.granbytv.com/3671__Antenna.jpg) by using a normal wire. The
> > wire is just a very normal copper wire. The result is : i don't see
> > the signal become stronger. I think i need a dish antenna. Any idea?
>
> > thanks
> > from Peter
>
> Your TV antenna isn't resonant at the right frequency, the impendence is
> mismatched, if you have an amplifier in the TV antenna line it may be
> filtering out the WiFi frequency and a whole lot of other possibilities.
> Bottom line is that your TV antenna isn't designed to work for WiFi.
>
> Omni directional antennas can also have gain. A "5/8 wave length"
> vertical
> antenna has gain, but is not directional in the sense "concentrating
> energy
> in a narrow direction".
>
> http://www.qsl.net/w4sat/five8th.htm
>
> There are lots of books out there on antenna theory and antenna
> construction, but you probably don't want to go into the subject far
> enough
> to understand what does what and why. Many variables have to be
> considered
> such as wavelength, impedance, reactance, height above ground, and many
> others.
>
> A simple WiFi antenna mounted on top of your RV may well do what you want
> to
> do.
>
> Ron
No , my TV antenna is just a piece of metal. No electronic component
inside. This experience told me if i plug my router antenna wire to a
metal, it will enlarge the signal
thanks
from Peter
Sorry Peter, but that is not how it works. You have to use an antenna for
the frequency you are using.
On May 7, 11:34 am, Jeff Liebermann <j...@comix.santa-cruz.ca.us>
wrote:
> Therefore, water is a better analogy than light because it creates a
> smaller catalyst for endless debate (and is far more fun for live
> demonstrations).
Yes, but threads like this, where the question has been answered 5x
over, are, at least, relatively better places to digress!
> Where the light versus 2.4GHz analogy falls apart is in fringing,
> dispersion, and edge effects. The Fresnel Zone for light is almost
> zilch and can usually be ignored. You can't do that for 2.4GHz.
> Obstructions just outside of the line of sight act differently.
For me, from my Television/Film lighting past, I recognized the term
"Fresnel" for the Fresnel lenses used on certain types of TV and film
spotlights.
>On May 7, 11:34 am, Jeff Liebermann <j...@comix.santa-cruz.ca.us>
>wrote:
>
>> Therefore, water is a better analogy than light because it creates a
>> smaller catalyst for endless debate (and is far more fun for live
>> demonstrations).
>
>Yes, but threads like this, where the question has been answered 5x
>over, are, at least, relatively better places to digress!
Well, I'm guilty of one indiscretion. I prefer complete, detailed,
and comprehensive answers, to one-line pontifications. I could have
simply stated "water is better, trust me" and left it at that. I
didn't. In theory, people asking such theoretical questions would
search with Google or Google Groups before asking, and find all 5x
rehashes of the same topic. However, they don't. So, it amuses me to
answer the same question over and over, but each time in a different
manner. Perhaps next time, instead of a water nozzle, I'll use a
different analogy. If quality doesn't work, perhaps quantity will
suffice.
Yes, very different. Think "edge diffraction". You don't get much of
that with light and optics unless you're into exotics and esoteria.
That's the problem with the Fresnel Zone calculations. People tend to
understand it in terms of optics (something anyone can see) and it
fails. The usual result with wi-fi is "I can see it, but I can't talk
to it" type of problems. The longer the path, the worse the problem.
Incidentally, 60% clearance is not the rule of thumb. More like 80%.
why antenna work? 
Linear Mode
