How to calculate increase of home wireless router range? [Archive]

Beverly Erlebacher

July 4th 06, 07:57 AM

Can you help me roughly CALCULATE how to increase the range of my home
Internet wireless WiFi setup to a shed 300 feet away from my house?

Presently, I can walk about half the way through the wooded area to the
shed with my laptop in hand before I lose the connection to the PCMCIA
802.11b,g Linksys card. Basically I need to gain 150 feet in "range".

But how?

At the store, I immediately become confused as I try to compare $30 USD
omnidirectional antennas (D-Link ANT24-070) that boost "power" by a claimed
7 db; $50 USD directional corner antennas (Hawking HAI15SC) that claim 15
dbi (whatever a dBi is); and $150 USD 802.11N routers that claim to boost
omnidirectional "range" by 4x (Linksys WRT300N).

How does an omnidirectional 7 db or directional 15 dBi boost in "power"
equate to range?

Approximately how many decibels of (omnidirectional or directional) power
do I really need to boost my WiFi range from about 150 feet to the 300 feet
I need?

Looking up what a decibel is
(http://en.wikipedia.org/wiki/Decibel#Definition), I
calculate the D-Link ANT24-070 omnidirectional antenna gives me about 5
times the power (assuming 7 db = 10^7/10 ~= 5); but does this get me the
additional 150 feet of range to my shed?

Spending almost twice as much money on the Hawking HAI15SC directional
antenna gets me roughly 30 times the power (assuming 15 db = 10^15/10 ~=
32); but is that enough power to get me the range to my shed?

Indeed, is there some way to add a Hawking 15db antenna on the receiving
end to get 1,000 times the power (15 db + 15 db = 30 db = 10^30/10 ~=
1,000); but what would I hook the wire output from this receiving antenna
to in the shed (I can't hook it to the pcmcia card, can I)?

Given those db calculations, how do I compare the antenna options with
replacing my home 802.11b,g router with the 4X range $150 USD Linksys
802.11n WRT300N router and the required $120 USD Linksys WPC300N PCMCIA
card (assuming 6 db = 10^6/10)?Will this three-antenna 802.11n router be
forced to drop down to 1X speeds because inside my house my kid's laptops
will all be using 802.11b or 802.11g? Or can the router work on both
802.11g to one computer and on 802.11n to the other computer at the same
time?

I'm so confused!

All I want is to make a well-informed buying decision to increase my WiFi
range reliably to 300 feet to a known point.

Can you help me sort out all these very confusing variable (to me anyway)?
I have no training in electrical engineering; but I can google.

Thank you,
Beverly

Reg Edwards

July 4th 06, 08:42 AM

"Beverly Erlebacher" > wrote in message
.. .
> Can you help me roughly CALCULATE how to increase the range of my
home
> Internet wireless WiFi setup to a shed 300 feet away from my house?
>
> Presently, I can walk about half the way through the wooded area to
the
> shed with my laptop in hand before I lose the connection to the
PCMCIA
> 802.11b,g Linksys card. Basically I need to gain 150 feet in
"range".
>
> But how?
>
> At the store, I immediately become confused as I try to compare $30
USD
> omnidirectional antennas (D-Link ANT24-070) that boost "power" by a
claimed
> 7 db; $50 USD directional corner antennas (Hawking HAI15SC) that
claim 15
> dbi (whatever a dBi is); and $150 USD 802.11N routers that claim to
boost
> omnidirectional "range" by 4x (Linksys WRT300N).
>
> How does an omnidirectional 7 db or directional 15 dBi boost in
"power"
> equate to range?
>
> Approximately how many decibels of (omnidirectional or directional)
power
> do I really need to boost my WiFi range from about 150 feet to the
300 feet
> I need?
>
> Looking up what a decibel is
> (http://en.wikipedia.org/wiki/Decibel#Definition), I
> calculate the D-Link ANT24-070 omnidirectional antenna gives me
about 5
> times the power (assuming 7 db = 10^7/10 ~= 5); but does this get me
the
> additional 150 feet of range to my shed?
>
> Spending almost twice as much money on the Hawking HAI15SC
directional
> antenna gets me roughly 30 times the power (assuming 15 db =
10^15/10 ~=
> 32); but is that enough power to get me the range to my shed?
>
> Indeed, is there some way to add a Hawking 15db antenna on the
receiving
> end to get 1,000 times the power (15 db + 15 db = 30 db = 10^30/10
~=
> 1,000); but what would I hook the wire output from this receiving
antenna
> to in the shed (I can't hook it to the pcmcia card, can I)?
>
> Given those db calculations, how do I compare the antenna options
with
> replacing my home 802.11b,g router with the 4X range $150 USD
Linksys
> 802.11n WRT300N router and the required $120 USD Linksys WPC300N
PCMCIA
> card (assuming 6 db = 10^6/10)?Will this three-antenna 802.11n
router be
> forced to drop down to 1X speeds because inside my house my kid's
laptops
> will all be using 802.11b or 802.11g? Or can the router work on both
> 802.11g to one computer and on 802.11n to the other computer at the
same
> time?
>
> I'm so confused!
>
> All I want is to make a well-informed buying decision to increase my
WiFi
> range reliably to 300 feet to a known point.
>
> Can you help me sort out all these very confusing variable (to me
anyway)?
> I have no training in electrical engineering; but I can google.
>
> Thank you,
> Beverly
==========================================

Very simply - four times the transmitter power ( +6 dB ) doubles the
range.

Is your receiver sufficiently sensitive? Or is the received signal
below the noise level?
----
Reg.

Beverly Erlebacher

July 4th 06, 08:49 AM

On Tue, 04 Jul 2006 06:28:16 -0000, Dave Platt wrote:
>>Can you help me roughly CALCULATE how to increase the range of my home
>>Internet wireless WiFi setup from 150 feet to a shed 300 feet away?

> Doubling the range requires 6 dB of additional gain from the antennas
> at one end or the other.

Hi Dave,

First thank you for taking the time to help me and anyone who read this.
Second, I'm going to have to go slowly with you so I'll respond one by one.

Third, does your statement that 6 dB of gain equates to 2 times the range
mean that the "square root" of the power difference is my key to
calculating the range?

That is, is this range calculation from dB power roughly true (based on
what you said)?

6 dB = 10^(6/10) ~= 4X the power, where the square root of 4X equals a
doubling the range (assuming an omnidirectional antenna)?

Beverly

Beverly Erlebacher

July 4th 06, 09:22 AM

> 6 dB = 10^(6/10) ~= 4X the power, where the square root of 4X equals a
> doubling the range (assuming an omnidirectional antenna)?

I'm hoping I can extrapolate from the above statement to calculate the dB
gain for the $150 Linksys WRT300N router which claims a 4X range
improvement (so I can compare the $50 antenna's effect with that of the
802.11n router).

Following your lead, the power improvement necessary for a 4X range
improvement is 4^2 = 16X power gain.

This 16X power gain then equates to about 12 dB (since 12 dB = 10^[12/10]
~= 16X power).

So, is it safe to calculate that the claimed 4X range improvement of the
Linksys WRT300N wireless broadband router can be compared to that of a 12
dB gain omnidirectional antenna?

Beverly

Beverly Erlebacher

July 4th 06, 09:36 AM

On Tue, 04 Jul 2006 06:28:16 -0000, Dave Platt wrote:
>>Can you help me roughly CALCULATE how to increase the range of my home
>>Internet wireless WiFi setup to a shed 300 feet away from my house?
>
> dBi refers to gain relative to an "isotropic" antenna
> dBd refers to gain relative to a half-wave dipole
> dBi numbers are approximately 2 dB higher than dBd numbers,
> for the same actual amount of gain.

Hi Dave,

Oh my. I guess the Hawking marketing folks were trying to trick me by
quoting a decibel number that was higher those I compared with.
15 dBi ~= 15 -2 ~= 13 dBd

That makes the $50 USD 15 dBi Hawking HAI15SC Hi_Gain Antenna drop down
from a gain of 32X power to only 20X power which gives me about a 4X range.

13 dBd = 10^(13/10) power ~= 20x power

Assuming the square of the power is the range, I get 4X range.
20^(1/2) ~= 4X range

Assuming my reliable range is 100 feet, that equates to 400 feet of range.
100 feet * 4 = 400 feet range

Interestingly, for comparison purposes, that is the SAME RANGE that the
much more expensive Linksys (Cisco) WRT300N router claims.

Do these calculations make sense?
Beverly

Beverly Erlebacher

July 4th 06, 09:48 AM

On Tue, 04 Jul 2006 06:28:16 -0000, Dave Platt wrote:
>>Can you help me roughly CALCULATE how to increase the range of my home
>>Internet wireless WiFi setup to a shed 300 feet away from my house?

> 3 dB of additional gain equates to twice the delivered power at a
> specific range. Because power falls off in proportion to the square
> of the distance, twice the power yields sqrt(2) or about 1.4 times the
> range, all else being equal (which it often isn't).
>
> 6 dB of additional gain is four times the delivered power at a given
> distance, or twice the range for the same amount of power.

So that I may compare the different options available at the store to me
for increasing my range, are these simplified calculations below correct?

a. 3 dBd additional gain = 10^(3/10) ~= 2x the delivered power
b. 2x power = 2^(1/2) effective range ~= 1.4X the range

b. 6 dBd additional gain = 10^(6/10) ~= 4x the delivered power
b. 4x power = 4^(1/2) effective range ~= 2X the range

Can someone let me know if these calculations are correct because that
helps me equate the different antennas and routers to the one measure I
desire, which is effective range in the area of 400 feet.

Beverly

Beverly Erlebacher

July 4th 06, 09:53 AM

On Tue, 04 Jul 2006 06:28:16 -0000, Dave Platt wrote:
>> Approximately how many decibels of (omnidirectional or directional)
>> power do I really need to boost my WiFi range from about 150 feet
>> to the 300 feet I need?
>
> The _minimum_ you appear to need is 6 dB of additional gain. I'd
> recommend trying for 10 dB or more in order to ensure a reliable
> connection.

May I ask WHERE that 6 dBd of gain is coming from?

Is it ONLY from the "better" antenna?

If that additional 6 dBd is coming from a "better" antenna, then why didn't
they put that better antenna on my router in the first place?

Since the antenna isn't "powerered", there is no external amplifier .... so
I am a bit confused as to WHERE that power is coming from?

Can you unconfusify me here?
Beverly

Beverly Erlebacher

July 4th 06, 10:48 AM

On Tue, 04 Jul 2006 06:28:16 -0000, Dave Platt wrote:
> It's possible to fabricate a corner reflector, or (even better) a
> parabolic reflector, out of material as inexpensive as cardboard
> (or posterboard or something like that) lined with aluminum foil.

Hmm. At first, I thought you were pulling my leg; but a simple google for
more details gave me more homemade WiFi antenna reading than I can handle
in a month. Whew. Here, for others to share, are the Yagi pringles can
antennas (aka cantenna) which purport to "refocus" the WiFi signal from my
router in my house to my shed 300 feet away.

http://en.wikipedia.org/wiki/Cantenna
http://www.oreillynet.com/cs/weblog/view/wlg/448
http://www.seattlewireless.net/index.cgi/PringlesCantenna
http://www.wi-fiplanet.com/reviews/article.php/3401501
http://www.turnpoint.net/wireless/has.html
http://www.binarywolf.com/249/pringles_cantenna.htm
http://verma.sfsu.edu/users/wireless/pringles.php
http://www.seattlewireless.net/index.cgi/CookieCantenna
http://webserver.computoredge.com/editorial/2339/cover.htm
http://www.signonsandiego.com/news/computing/personaltech/20050613-9999-lz1b13canned.html
http://www.overclock.net/faqs/17669-how-make-pringles-can-signal-booster.html
http://www.g4tv.com/screensavers/features/40546/Pringles_Can_WiFi_Antenna.html
http://www.netscum.com/~clapp/wireless.html
http://www.flickr.com/photos/binarywolf/sets/837698/
http://linuxathome.com/files_images/cantenna.pdf

Given that there are two fundamental design styles:
a) Parabola
b) Tube

Do folks here recommend the pringles cantenna or the pie tin antenna for my
2-antenna router 802.11b,g directional application where I need to also
feed the computers within the house in addition to the shed 300 feet away?

Beverly

Beverly Erlebacher

July 4th 06, 12:07 PM

On Tue, 04 Jul 2006 05:50:02 -0400, Rôgêr wrote:
>> Do folks here recommend the pringles cantenna or the pie tin antenna for my
>> 2-antenna router 802.11b,g directional application where I need to also
>> feed the computers within the house in addition to the shed 300 feet away?
>
> I use panel antennas almost exclusively, exceptions being some 24dbi
> mesh antennas for backhaul.

Hi Rôgêr,

After reading all the articles posted, I now understand that:

a) The pringles can is hip; but it's the worst performer
http://www.oreillynet.com/cs/weblog/view/wlg/448
(it's not even metal foil lined and it's too small in diameter)

b) The coffee cantenna is more effective than the pringles cantenna
http://www.oreillynet.com/cs/user/view/wlg/1124

c) The dish antenna is the simplest of all and almost as good
http://www.freeantennas.com/projects/template
http://www.freeantennas.com/projects/template2/index.html

I also see, as Rod Speed so kindly noted, that the give and take is that we
lose range in some directions in favor of range in the desired direction.
Fair enough.

My one question is a practical one.

Why are there two antennas on my router anyway? Is one transmit and the
other receive? Or are they both transmit and receive?

Given I have TWO omnidirectional antennas on my wireless router, if I put
the parabolic dish antenna on one to direct it to my shed, does that allow
the OTHER antenna to radiate around the house to handle the other computers
roving around the house?

Beverly

Highland Ham

July 4th 06, 01:21 PM

Beverly Erlebacher wrote:
> Can you help me roughly CALCULATE how to increase the range of my home
> Internet wireless WiFi setup to a shed 300 feet away from my house?
>
> Presently, I can walk about half the way through the wooded area to the
> shed with my laptop in hand before I lose the connection to the PCMCIA
> 802.11b,g Linksys card. Basically I need to gain 150 feet in "range".
>
> But how?
====================================
Having followed today's postings on this topic , I see that there is a
wooded area between your house and shed, hence there seems to be no free
line of sight between the house and the shed.
That's why it is difficult to calculate/predict the Gain you need to
penetrate the wooded area with a 2.4 GHz signal.

If you wish to use the laptop inside the shed at a fixed location it
MIGHT be good enough if you install (for example)a corner reflector yagi
(High Gain)antenna at both the house AND the shed. However then your
laptop needs a plug-in PCMCIA WiFi tansceiver with a connection for an
external antenna.
One of such units is the Make: Buffalo - Air Station Turbo G ,High Power
-unit which also has a built-in antenna.
Note : The coaxial cable between the 2 devices and their associated
antenna should be limited to only a few metres because of the high
frequency being 2.4GHz

Communication here is 2 way . Your laptop might receive the ( antenna
amplified) signal from your router located in the house ,but that does
not mean the router will receive the signal from the laptop without
additional facilities at the laptop.

Again , because of the probably partly obstructed path (wooded area) it
is difficult making any sensible calculations.

Frank GM0CSZ / KN6WH

xpyttl

July 4th 06, 02:30 PM

"Highland Ham" > wrote in message
...

> Having followed today's postings on this topic , I see that there is a
> wooded area between your house and shed, hence there seems to be no free
> line of sight between the house and the shed.
> That's why it is difficult to calculate/predict the Gain you need to
> penetrate the wooded area with a 2.4 GHz signal.

YES - exactly.

I have been able to go laptop to laptop almost a mile with normal PCMCIA
cards, using patch antennas. (Well - normal cards modified to bring out the
signal to the antenna.) These antennas can be astonishingly directional.
Indeed, at 2.4 MHz, it is pretty easy to get antennas with amazing amounts
of gain. This translates into VERY CAREFUL aiming of the antenna. Also keep
in mind that at 2.4 GHz, RG-58 ain't gonna cut it. Most of what you put in
to one end of any normal coax will be sucked up by the coax and won't make
it out the other end. You need to use cable appropriate to the frequency.

With a wooded area, not only is it very difficult to calculate, but tiny
differences in the positioning of the two ends is going to make a huge
difference, as is summer to winter. Even a windy day is going to change
things.

Because of the small size, it can be pretty simple to build a yagi for
wireless. Yagis won' t have the gain of some of the other types of antennas,
but at the same time, they won't be nearly as critical.

Depending on your situation, you may find a directional antenna a better
choice than more power. Lots of people driving by like to "borrow" your
wireless, and I personally don't like the idea of strangers roaming my LAN,
even if they aren't typical crackers. (Seems to me that salesmen are the
most common intruders. They have learned that they can find a wireless
connection almost anywhere). I find getting coverage into the back yard,
while NOT getting coverage well into the street is a bit of a challenge.
Yes, I use encryption and MAC filtering, but I'd still rather not have lots
of wardrivers trying to break in.

...

Geoffrey S. Mendelson

July 4th 06, 03:30 PM

xpyttl wrote:

> I have been able to go laptop to laptop almost a mile with normal PCMCIA
> cards, using patch antennas. (Well - normal cards modified to bring out the
> signal to the antenna.) These antennas can be astonishingly directional.
> Indeed, at 2.4 MHz, it is pretty easy to get antennas with amazing amounts
> of gain.

There are restrictions on the RADIATED power, transmitter output power,
etc of unlicensed 2.4gHz transmitters, such as WiFi. You should check
them out. They vary from country to country.

If you have a ham license, then you can use 2.4gHz for data transmission,
but then you are restricted in transmission mode, encryption and data
content.

For example, the infamous Pringles can antenna was developed in the U.S. by
an FBI agent in the course of an investigation. It's use as a WiFi transmission
antenna is illegal in many places. The well pubicised long distance link in
Egypt was illegal.

Here in Israel we are limited to 100mW EIRP for civilian useage, except
for ham satellite operations which are limited to 25w.

BTW, there are limitations in the U.S. too, I just don't know them.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

Beverly Erlebacher

July 4th 06, 06:58 PM

On Tue, 4 Jul 2006 11:03:49 -0400, Peter Pan wrote:
>> Can you help me roughly CALCULATE how to increase the range of my
>> home Internet wireless WiFi setup to a shed 300 feet away
....
> I Had a linksys WRT54G in the house attached to my sat,
> and used one of the 4 router outputs to daisy chain one to the wan input of
> another WRT54G (same ssid) and a semi-directional antenna pointed towards
> the garage about 500ft away,

Hi Peter Pan,

Oh my! Is "wireless" daisy chaining workable? Is it that easy?

I did not think I could just daisy chain multiple routers! Are you sure?
(My shed has no power but I think I could run an extension cord into it if
that would make things workable.)

Would I just set the second Linksys router (which, amazingly, has it's own
wikipedia entry at http://en.wikipedia.org/wiki/WRT54G) in the shed on the
same channel (SSID=12, name = default) as the first router in the house?

That is, could I put one linksys WRT54G in the house (perhaps with one
antenna replaced with a 7 dBd higher-gain directional antenna); and then
put the other Linksys WRT54G in the shed 300 feet away (perhaps with one of
it's antennas replaced with a similar 7 dBd directional antenna)?

Or, is it best to hardwire with cat5 the first router downstairs in the
house to the second router, say upstairs in the attic window pointing the
antenna toward the shed? I didn't even know that two routers could be daisy
chained. That might solve my dilemma.

Can someone confirm that two routers could be daisy chained either by wire
cat5 cable or by wireless signals as long as they use the same SSID channel
and network name? That solution seems to easy to be true ...

Beverly

Beverly Erlebacher

July 4th 06, 07:15 PM

On Tue, 04 Jul 2006 09:07:39 -0500, wrote:
> Here is an easy way to hack your $60 wireless router into a $600
> router (they use Linksys as the example):

Wow. I've never "modified" a router before but that is interesting that one
can increase the $75 Linksys WRT54G router
(http://en.wikipedia.org/wiki/WRT54G) RF output from 28 millwatts up to 251
milliwatts (http://tinyurl.com/lpk7w).

Being true to the original intent of this thread, how do I CALCULATE what
that does to my range?

Is this 9 dBd calculation of the modification roughly correct?
a) Power gain = Power2/Power1 = 251/28 milliwatts = 9x power gain
b) Range gain = sqrt(Power gain) = sqrt(9) = 3X range gain
c) Range = original range * range gain = 100 feet * 3 = 300 feet

Beverly

Beverly Erlebacher

July 4th 06, 07:18 PM

On Tue, 04 Jul 2006 11:48:12 +0100, Highland Ham wrote:

> Beverly Erlebacher wrote:
>> Can you help me roughly CALCULATE how to increase the range of my home
>> Internet wireless WiFi setup to a shed 300 feet away from my house?
>>
>> Presently, I can walk about half the way through the wooded area to the
>> shed with my laptop in hand before I lose the connection to the PCMCIA
>> 802.11b,g Linksys card. Basically I need to gain 150 feet in "range".
>>
>> But how?
> ================================================== ==
> Having followed today's postings on this topic , I see that there is a
> wooded area between your house and shed, hence there seems to be no free
> line of sight between the house and the shed.
> That's why it is difficult to calculate/predict the Gain you need to
> penetrate the wooded area with a 2.4 GHz signal.
>
> If you wish to use the laptop inside the shed at a fixed location it
> MIGHT be good enough if you install a corner reflector yagi (High
> Gain)antenna at both the house AND the shed. However then your laptop
> needs a plug-in PCMCIA WiFi tansceiver with a connection for an external
> antenna.
> One of such units is the Make: Buffalo - Air Station Turbo G ,High Power
> -unit which also has a built-in antenna.
> Note : The coaxial cable between the 2 devices and their associated
> antenna should be limited to only a few metres because of the high
> frequency being 2.4GHz
>
> Communication here is 2 way . Your laptop might receive the ( antenna
> amplified) signal from your router located in the house ,but that does
> not mean the router will receive the signal from the laptop without
> additional facilities at the laptop.
>
> Again , because of the probably partly obstructed path (wooded area) it
> is difficult making any sensible calculations.
>
> Frank GM0CSZ / KN6WH

Hi Highland Ham,

I see there are multiple solutions. Probably on the end of my list is
adding a wire to the laptop because then it wouldn't be wireless. Still,
it's an intriguing idea (I never knew laptops could have fixed antenna's
connected to them by wire).

If I do use two antennas, does that "add" the gain?

a) Antenna 1 transmits with a directional gain of, say 7 dBd
b) Antenna 2 receives with a directional gain of, say 7 dBd
c) Does that get me a 14 dBd overall gain?

Beverly

Beverly Erlebacher

July 4th 06, 07:40 PM

On Tue, 04 Jul 2006 06:11:27 -0700, Dan Richardsonk6mhe wrote:
> If your goal is to increase your range then add an extender
> (hams would prefer to call them repeaters).

Oh my. The seemingly perfect option.

I had come across the concept of wireless "repeaters" in my initial
googling before I went to the store, e.g., in this Microsoft "how to
increase range" article
http://www.microsoft.com/athome/moredone/wirelesstips.mspx and in this
"Extending WLAN Range" article
http://www.wi-fiplanet.com/tutorials/article.php/1571601

The repeater most often recommended was the "Linksys Wireless-G Range
Expander WRE54G".

However, I can't find that 802.11b,g WiFi repeater (aka range expander or
extender) anywhere in the local stores. The salesperson who sold me the
$300 USD 802.11n router and PCMCIA card combination said they didn't work
so they dropped it.

This solution seems to be the most elegant of all (but someone else
suggested just using a second router).

Can someone unconfusify the situation?

Is placing a repeater (on the same SSID) in the shed really the same as
adding a second router instead?

Beverly

Beverly Erlebacher

July 4th 06, 07:47 PM

On Tue, 04 Jul 2006 08:17:19 -0700, David wrote:
> A "range extender" or "repeater" will cut the speed in half.

Hi David,

Interesting this speed difference. I'm worried about RANGE and all of a
sudden other factors come into play! Thank you for enlightening me. I know
more now than I ever did from you wonderful guys!

As I noted to someone else just now, I DID try to find the "Linksys
Wireless-G Range Expander WRE54G" WiFi repeater in the local stores but
they did not exist in any of the three stores I checked.

Also, some of the articles talk about an "access point"
(http://www.wi-fiplanet.com/tutorials/article.php/1571601).

Can someone tell me what part of my setup I would call the "access point"?

Beverly

Beverly Erlebacher

July 4th 06, 08:06 PM

On Tue, 04 Jul 2006 17:57:22 GMT, stephen wrote:
> but - you mentioned you could run power out to your shed. Why not plumb it
> in for power and networking?
> then you can add a separate access point there and avoid antennae, gain,
> loss through leaves and the rest.

Hi Stephen,
I'm confused about this "access point" thing.

Is that the same as a "router"?

Is it as simple as buying a second router (routers are familiar to me) and
just hooking that second router to the first router by cable and that would
extend my range by the distance of the cable connecting the two routers?

This is a key confusion point for me!
Beverly

Rod Speed

July 4th 06, 08:11 PM

Beverly Erlebacher > wrote:
> On Tue, 04 Jul 2006 08:17:19 -0700, David wrote:
>> A "range extender" or "repeater" will cut the speed in half.
>
> Hi David,
>
> Interesting this speed difference. I'm worried about RANGE and all of
> a sudden other factors come into play! Thank you for enlightening me.
> I know more now than I ever did from you wonderful guys!
>
> As I noted to someone else just now, I DID try to find the "Linksys
> Wireless-G Range Expander WRE54G" WiFi repeater in the local stores
> but they did not exist in any of the three stores I checked.
>
> Also, some of the articles talk about an "access point"
> (http://www.wi-fiplanet.com/tutorials/article.php/1571601).

> Can someone tell me what part of my setup I would call the "access point"?

The wireless part.

Rod Speed

July 4th 06, 08:11 PM

Beverly Erlebacher > wrote:
> On Tue, 04 Jul 2006 05:50:02 -0400, Rôgêr wrote:
>>> Do folks here recommend the pringles cantenna or the pie tin
>>> antenna for my 2-antenna router 802.11b,g directional application
>>> where I need to also feed the computers within the house in
>>> addition to the shed 300 feet away?
>>
>> I use panel antennas almost exclusively, exceptions being some 24dbi
>> mesh antennas for backhaul.
>
> Hi Rôgêr,
>
> After reading all the articles posted, I now understand that:
>
> a) The pringles can is hip; but it's the worst performer
> http://www.oreillynet.com/cs/weblog/view/wlg/448
> (it's not even metal foil lined and it's too small in diameter)
>
> b) The coffee cantenna is more effective than the pringles cantenna
> http://www.oreillynet.com/cs/user/view/wlg/1124
>
> c) The dish antenna is the simplest of all and almost as good
> http://www.freeantennas.com/projects/template
> http://www.freeantennas.com/projects/template2/index.html
>
> I also see, as Rod Speed so kindly noted, that the give and take is
> that we lose range in some directions in favor of range in the
> desired direction. Fair enough.
>
> My one question is a practical one.
>
> Why are there two antennas on my router anyway?

That gives a more reliable coverage than with one.

> Is one transmit and the other receive?
> Or are they both transmit and receive?

They're normally both transmit and receive.

> Given I have TWO omnidirectional antennas on my wireless router,
> if I put the parabolic dish antenna on one to direct it to my shed,
> does that allow the OTHER antenna to radiate around the house
> to handle the other computers roving around the house?

Yes.

xpyttl

July 4th 06, 08:38 PM

"Geoffrey S. Mendelson" > wrote in message
...

> If you have a ham license, then you can use 2.4gHz for data transmission,
> but then you are restricted in transmission mode, encryption and data
> content.

And wireless channels, as well. Some of the channels are outside the U.S.
ham bands. Since this is an amateur radio newsgroup, I made the (possibly
rash) assumption that OP was aware of these limitations. For amateurs in
the U.S., the main issue is encryption. Few of us can afford to get
anywhere near the power limits at these frequencies!

...

Allodoxaphobia

July 4th 06, 09:31 PM

On Tue, 4 Jul 2006 08:30:46 -0400, xpyttl wrote:

....
> Indeed, at 2.4 MHz, it is pretty easy to get antennas with amazing amounts
> of gain. ......

Sigh... If only that were true! HI!HI!

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
38.24N 104.55W | @ config.com | Jonesy | OS/2
*** Killfiling google posts: <http//jonz.net/ng.htm>

Geoffrey S. Mendelson

July 4th 06, 11:31 PM

Beverly Erlebacher wrote:
> I'm confused about this "access point" thing.

An access point is a device with an ethernet port on one side and a wifi
port on the other. In technical terms it would be called a "bridge". It
"bridges" two seperate network segments, although in this case they use
different topologies (100Base-T and WiFi).

> Is that the same as a "router"?

The usual WiFi router consists of a four port ethernet hub (LAN ports),
a seperate single ethernet port (WAN port) and a WiFi access point.
It is set up to "route" between the single (aka WAN) port and the other
two ports, the LAN and WiFi. Most of what it does for routing is NAT (network
address translation) and some sort of IP tunneling.

If you ignore the WAN port and just use the LAN ports, you have a four port
hub and an access point.

> Is it as simple as buying a second router (routers are familiar to me) and
> just hooking that second router to the first router by cable and that would
> extend my range by the distance of the cable connecting the two routers?

Yes. Just make sure to use the LAN ports. It would be best to use different
channels. Most WiFi clients are smart enough to use the channel that is the
strongest if they have access points on more than one with the same SSID.

Make sure to use encryption. Encryption is NOT to keep your data safe,
nothing can do that. If someone is intent on accessing your network, WEP
encryption will not keep them out.

What it is for is to convince the guy driving down the street looking for an
open network to send out SPAM, or "share" kiddie porn, to drive on.
Unfortunately, most users don't even change the SSID of their network, let
alone set an encryption key.

Having tuned in late, if you want to have an open network, look up PublicIP.
It's a "live cd" that runs on a PII or better (x86) computer and provides
all the functions you need to offer a secure and safe open network.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

Geoffrey S. Mendelson

July 4th 06, 11:31 PM

Rod Speed wrote:
>> Is one transmit and the other receive?
>> Or are they both transmit and receive?
>
> They're normally both transmit and receive.

That's a shame. Here in Israel we are limited to 100mw EIRP, which
severly limits the transmit antenna. There is NO limitation on the
receive antenna.

Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

Rod Speed

July 5th 06, 12:27 AM

Geoffrey S. Mendelson > wrote
> Rod Speed wrote

>>> Is one transmit and the other receive?
>>> Or are they both transmit and receive?

>> They're normally both transmit and receive.

> That's a shame. Here in Israel we are limited to 100mw EIRP, which severly
> limits the transmit antenna. There is NO limitation on the receive antenna.

A receive antenna has no EIRP, it doesnt radiate any real power.

xpyttl

July 5th 06, 02:18 PM

hehe -- getting gain at the antenna isn't such a big deal ... getting the
goo TO the antenna is a whole 'nuther can of worms. It's pretty easy to
come up with 10 dB of gain and 20 dB of feedline loss! Of course, for WiFi,
we're often interested in gain AND omnidirectional -- that is something of a
challenge.

...

"Allodoxaphobia" > wrote in message
...
> On Tue, 4 Jul 2006 08:30:46 -0400, xpyttl wrote:
>
> ...
>> Indeed, at 2.4 MHz, it is pretty easy to get antennas with amazing
>> amounts
>> of gain. ......
>
> Sigh... If only that were true! HI!HI!
>
> Jonesy
> --
> Marvin L Jones | jonz | W3DHJ | linux
> 38.24N 104.55W | @ config.com | Jonesy | OS/2
> *** Killfiling google posts: <http//jonz.net/ng.htm>

Geoffrey S. Mendelson

July 5th 06, 03:30 PM

xpyttl wrote:
> hehe -- getting gain at the antenna isn't such a big deal ... getting the
> goo TO the antenna is a whole 'nuther can of worms. It's pretty easy to
> come up with 10 dB of gain and 20 dB of feedline loss! Of course, for WiFi,
> we're often interested in gain AND omnidirectional -- that is something of a
> challenge.

POE! POE! POE! (Power over ethernet). Put the access point at the antenna,
run a cat-5 cable (4 twisted pairs) to it. Four get used for the network
connection, 4 get used for DC.

Not only does it work well, but CAT-5 wire is cheap, 2.4gHz low loss coax
is not.

Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

John - KD5YI

July 8th 06, 06:08 PM

Rod Speed wrote:
> Geoffrey S. Mendelson > wrote
>
>>Rod Speed wrote
>
>
>>>>Is one transmit and the other receive?
>>>>Or are they both transmit and receive?
>
>
>>>They're normally both transmit and receive.
>
>
>>That's a shame. Here in Israel we are limited to 100mw EIRP, which severly
>>limits the transmit antenna. There is NO limitation on the receive antenna.
>
>
> A receive antenna has no EIRP, it doesnt radiate any real power.
>
>

Actually, when properly matched, it radiates half the received power.

Don K

July 8th 06, 07:37 PM

"John - KD5YI" > wrote in message news:XLQrg.2896$bd4.372@trnddc01...
> Rod Speed wrote:
>>
>> A receive antenna has no EIRP, it doesnt radiate any real power.
>
> Actually, when properly matched, it radiates half the received power.

How do you get that?
If the receiver input impedance is matched to the antenna, all the
received power is absorbed. There is no reflection. There is no radiation.

If the receiver matching is for optimal noise figure, there may be
some reflection and reradiation, but there's nothing pinning it to
be half the received power.

Don

Roy Lewallen

July 8th 06, 09:26 PM

Don K wrote:
> "John - KD5YI" > wrote in message news:XLQrg.2896$bd4.372@trnddc01...
>> Rod Speed wrote:
>>> A receive antenna has no EIRP, it doesnt radiate any real power.
>> Actually, when properly matched, it radiates half the received power.
>
>
> How do you get that?
> If the receiver input impedance is matched to the antenna, all the
> received power is absorbed. There is no reflection. There is no radiation.
>
> If the receiver matching is for optimal noise figure, there may be
> some reflection and reradiation, but there's nothing pinning it to
> be half the received power.

John is correct. A receiving antenna, when matched, reradiates half the
power it receives. An impinging field induces current in the antenna.
This causes radiation, just like the current in a transmitting antenna.
As it turns out, when the antenna is matched, the amount of power
radiated equals the amount of power delivered to the load, and that's
the best you can do. If you'd like a more in-depth and mathematical
explanation, you can find it in any antenna text, often discussed as
"scattering".

If a receiving antenna did absorb all the impinging power, it would be a
lot easier to make a shield or a stealth aircraft.

Roy Lewallen, W7EL

Rod Speed

July 8th 06, 09:35 PM

John - KD5YI > wrote:
> Rod Speed wrote:
>> Geoffrey S. Mendelson > wrote
>>
>>> Rod Speed wrote
>>
>>
>>>>> Is one transmit and the other receive?
>>>>> Or are they both transmit and receive?
>>
>>
>>>> They're normally both transmit and receive.
>>
>>
>>> That's a shame. Here in Israel we are limited to 100mw EIRP, which
>>> severly limits the transmit antenna. There is NO limitation on the
>>> receive antenna.
>>
>>
>> A receive antenna has no EIRP, it doesnt radiate any real power.
>>
>>
>
>
> Actually, when properly matched, it radiates half the received power.

Wrong.

Rod Speed

July 8th 06, 09:39 PM

Roy Lewallen > wrote
> Don K wrote
>> John - KD5YI > wrote
>>> Rod Speed wrote

>>>> A receive antenna has no EIRP, it doesnt radiate any real power.

>>> Actually, when properly matched, it radiates half the received power.

>> How do you get that?
>> If the receiver input impedance is matched to the antenna, all the
>> received power is absorbed. There is no reflection. There is no
>> radiation.

>> If the receiver matching is for optimal noise figure, there may be
>> some reflection and reradiation, but there's nothing pinning it to
>> be half the received power.

> John is correct.

Nope.

> A receiving antenna, when matched, reradiates half the power it receives.

Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.

> An impinging field induces current in the antenna. This causes radiation, just like the
> current in a transmitting antenna. As it turns out, when the antenna is matched, the
> amount of power radiated equals the amount of power delivered to the load, and that's
> the best you can do.

Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.

> If you'd like a more in-depth and mathematical explanation, you can find it in any
> antenna text, often discussed as "scattering".

Not relevant to the original point, any effect on the EIRP restriction.

> If a receiving antenna did absorb all the impinging power, it would be a lot easier to
> make a shield or a stealth aircraft.

Not relevant to the original point, any effect on the EIRP restriction.

John L. Sielke

July 8th 06, 10:42 PM

Rod Speed wrote:
> Roy Lewallen > wrote
>> Don K wrote
>>> John - KD5YI > wrote
>>>> Rod Speed wrote
>
>>>>> A receive antenna has no EIRP, it doesnt radiate any real power.
>
>>>> Actually, when properly matched, it radiates half the received power.
>
>>> How do you get that?
>>> If the receiver input impedance is matched to the antenna, all the
>>> received power is absorbed. There is no reflection. There is no
>>> radiation.
>
>>> If the receiver matching is for optimal noise figure, there may be
>>> some reflection and reradiation, but there's nothing pinning it to
>>> be half the received power.
>
>> John is correct.
>
> Nope.
>
>> A receiving antenna, when matched, reradiates half the power it receives.
>
> Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.
>
>> An impinging field induces current in the antenna. This causes radiation, just like the
>> current in a transmitting antenna. As it turns out, when the antenna is matched, the
>> amount of power radiated equals the amount of power delivered to the load, and that's
>> the best you can do.
>
> Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.
>
>> If you'd like a more in-depth and mathematical explanation, you can find it in any
>> antenna text, often discussed as "scattering".
>
> Not relevant to the original point, any effect on the EIRP restriction.
>
>> If a receiving antenna did absorb all the impinging power, it would be a lot easier to
>> make a shield or a stealth aircraft.
>
> Not relevant to the original point, any effect on the EIRP restriction.
>
>
Always amazinmg how when some people are proven wrong, the revert to the "Is
NOT, IS NOT," type of argument used by small children, then when that doesn't
work, the argument becomes irrelevant.

Rod, I suggest you LEARN something from your intellectual and technical betters
BEFORE you show the world your ignorance.

John

John L. Sielke

July 8th 06, 10:45 PM

Roy Lewallen

July 8th 06, 11:00 PM

Rod Speed wrote:
> Roy Lewallen > wrote
> . . .
>> A receiving antenna, when matched, reradiates half the power it receives.
>
> Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.
> . . .

It's real power, but that power all comes from the impinging field; it's
not contributing any new power. So you're right that the EIRP
restriction doesn't apply. The receive antenna reduces the amount of
power in the field by the amount delivered to the antenna's termination,
plus any losses along the way. The intent of the EIRP restriction is to
limit the amount of field strength added by a transmitter.

Roy Lewallen, W7EL

Rod Speed

July 8th 06, 11:12 PM

John L. Sielke > wrote:
> Rod Speed wrote:
>> Roy Lewallen > wrote
>>> Don K wrote
>>>> John - KD5YI > wrote
>>>>> Rod Speed wrote
>>
>>>>>> A receive antenna has no EIRP, it doesnt radiate any real power.
>>
>>>>> Actually, when properly matched, it radiates half the received
>>>>> power.
>>
>>>> How do you get that?
>>>> If the receiver input impedance is matched to the antenna, all the
>>>> received power is absorbed. There is no reflection. There is no
>>>> radiation.
>>
>>>> If the receiver matching is for optimal noise figure, there may be
>>>> some reflection and reradiation, but there's nothing pinning it to
>>>> be half the received power.
>>
>>> John is correct.
>>
>> Nope.
>>
>>> A receiving antenna, when matched, reradiates half the power it
>>> receives.
>>
>> Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.
>>
>>> An impinging field induces current in the antenna. This causes
>>> radiation, just like the current in a transmitting antenna. As it
>>> turns out, when the antenna is matched, the amount of power
>>> radiated equals the amount of power delivered to the load, and
>>> that's the best you can do.
>>
>> Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.
>>
>>> If you'd like a more in-depth and mathematical explanation, you can
>>> find it in any antenna text, often discussed as "scattering".
>>
>> Not relevant to the original point, any effect on the EIRP
>> restriction.
>>
>>> If a receiving antenna did absorb all the impinging power, it would
>>> be a lot easier to make a shield or a stealth aircraft.
>>
>> Not relevant to the original point, any effect on the EIRP
>> restriction.

> Always amazinmg how when some people are proven wrong, the
> revert to the "Is NOT, IS NOT," type of argument used by small
> children, then when that doesn't work, the argument becomes irrelevant.

Never ever could bull**** its way out of a wet paper bag.

> Rod, I suggest you LEARN something from your intellectual and
> technical betters BEFORE you show the world your ignorance.

Never ever could bull**** its way out of a wet paper bag.

While your original was technically correct, its completely
irrelevant to what was actually being discussed, WHETHER
THE RECEIVE ANTENNA EVER RADIATES ENOUGH TO
BE RELEVANT TO THE EIRP RESTRICTION.

Rod Speed

July 8th 06, 11:15 PM

Roy Lewallen > wrote:
> Rod Speed wrote:
>> Roy Lewallen > wrote
>> . . .
>>> A receiving antenna, when matched, reradiates half the power it
>>> receives.
>>
>> Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.

> It's real power,

Yes, BUT NOT IN THE EIRP RESTRICTION SENSE.

> but that power all comes from the impinging field; it's not contributing any new power.
> So you're right that the EIRP restriction doesn't apply.

And that is what was being discussed when John made such a
spectacular fool of himself mindlessly rabbiting on about what
is no news to anyone with a clue about receiving antennas.

> The receive antenna reduces the amount of power in the field by the amount delivered to
> the antenna's termination, plus any losses along the way. The intent of the EIRP
> restriction is to limit the amount of field strength added by a
> transmitter.

Duh. So John was mindlessly rabbiting on about a complete
irrelevancy WHEN THE EIRP RESTRICTION WAS BEING DISCUSSED.

Mark McIntyre

July 9th 06, 12:08 AM

On Sun, 9 Jul 2006 07:12:11 +1000, in alt.internet.wireless , "Rod
Speed" > wrote:

>John L. Sielke > wrote:
>
>> Always amazinmg how when some people are proven wrong, the
>> revert to the "Is NOT, IS NOT," type of argument used by small
>> children, then when that doesn't work, the argument becomes irrelevant.
>
>Never ever could bull**** its way out of a wet paper bag.
>
>> Rod, I suggest you LEARN something from your intellectual and
>> technical betters BEFORE you show the world your ignorance.
>
>Never ever could bull**** its way out of a wet paper bag.
>
>While your original was technically correct, its completely
>irrelevant to what was actually being discussed, WHETHER
>THE RECEIVE ANTENNA EVER RADIATES ENOUGH TO
>BE RELEVANT TO THE EIRP RESTRICTION.

I've not been following this thread, but I can tell you straight off,
I am significantly more inclined to believe the guys who are not
shouting and hurling abuse.

Make of that what you will, but my suggestion is to counter with
rational argument backed up by references and facts, rather than
insults and obscenities.

--
Mark McIntyre

Rod Speed

July 9th 06, 01:30 AM

Mark McIntyre > wrote
> Rod Speed > wrote
>> John L. Sielke > wrote

>>> Always amazinmg how when some people are proven wrong, the
>>> revert to the "Is NOT, IS NOT," type of argument used by small
>>> children, then when that doesn't work, the argument becomes irrelevant.

>> Never ever could bull**** its way out of a wet paper bag.

>>> Rod, I suggest you LEARN something from your intellectual and
>>> technical betters BEFORE you show the world your ignorance.

>> Never ever could bull**** its way out of a wet paper bag.

>> While your original was technically correct, its completely
>> irrelevant to what was actually being discussed, WHETHER
>> THE RECEIVE ANTENNA EVER RADIATES ENOUGH TO
>> BE RELEVANT TO THE EIRP RESTRICTION.

> I've not been following this thread, but I can tell you
> straight off, I am significantly more inclined to believe
> the guys who are not shouting and hurling abuse.

You have always been, and always will be, completely and utterly irrelevant.

What you may or may not be inclined to believe in spades.

Anyone with a clue considers the facts, not the style stuff, ****wit.

> Make of that what you will,

I flush it where it belongs.

> but my suggestion is to counter with rational
> argument backed up by references and facts,

Dont need 'references' on that basic fact that even
when the receiving antenna does reradiate about
half of what it receives, THAT IS COMPLETELY
IRRELEVANT TO THE LEGISLATED ERIP LEVEL.

> rather than insults and obscenities.

I suggest you take your stupid suggestion
and shove it up your arse, where it belongs.

Don K

July 9th 06, 02:50 AM

"Roy Lewallen" > wrote in message ...
> Don K wrote:
>> "John - KD5YI" > wrote in message news:XLQrg.2896$bd4.372@trnddc01...
>>> Rod Speed wrote:
>>>> A receive antenna has no EIRP, it doesnt radiate any real power.
>>> Actually, when properly matched, it radiates half the received power.
>>
>>
>> How do you get that?
>> If the receiver input impedance is matched to the antenna, all the
>> received power is absorbed. There is no reflection. There is no radiation.
>>
>> If the receiver matching is for optimal noise figure, there may be
>> some reflection and reradiation, but there's nothing pinning it to
>> be half the received power.
>
> John is correct. A receiving antenna, when matched, reradiates half the power it receives. An
> impinging field induces current in the antenna. This causes radiation, just like the current in a
> transmitting antenna. As it turns out, when the antenna is matched, the amount of power radiated
> equals the amount of power delivered to the load, and that's the best you can do. If you'd like a
> more in-depth and mathematical explanation, you can find it in any antenna text, often discussed
> as "scattering".
>
> If a receiving antenna did absorb all the impinging power, it would be a lot easier to make a
> shield or a stealth aircraft.
>
> Roy Lewallen, W7EL

Maybe to some extent, it's a matter of nit-picking over what
"received power" means. You can think of an antenna as having an
effective aperture size over which it captures all the energy
crossing that cross-sectional area. To me it's logical to think
of "received power" as the power that actually gets scooped
up and delivered.

Effective aperture increases with antenna gain. Obviously something
like a dipole has a relatively small effective aperture. But the
effective aperture of a high-gain horn antenna for instance, will
approach its actual physical cross-sectional area.

For instance, look at Figure 13 in this pdf.
http://www.coe.montana.edu/ee/rwolff/EE548/EE548-S06/UWB/Intro_UWBAntennas.pdf

Don

John - KD5YI

July 9th 06, 03:43 AM

Rod Speed wrote:
> John - KD5YI > wrote:
>
>>Rod Speed wrote:
>>
>>>Geoffrey S. Mendelson > wrote
>>>
>>>
>>>>Rod Speed wrote
>>>
>>>
>>>>>>Is one transmit and the other receive?
>>>>>>Or are they both transmit and receive?
>>>
>>>
>>>>>They're normally both transmit and receive.
>>>
>>>
>>>>That's a shame. Here in Israel we are limited to 100mw EIRP, which
>>>>severly limits the transmit antenna. There is NO limitation on the
>>>>receive antenna.
>>>
>>>
>>>A receive antenna has no EIRP, it doesnt radiate any real power.
>>>
>>>
>>
>>
>>Actually, when properly matched, it radiates half the received power.
>
>
> Wrong.

Wrong.

xray

July 9th 06, 12:00 PM

On Sun, 9 Jul 2006 09:30:46 +1000, "Rod Speed" >
wrote, in part:

>What you may or may not be inclined to believe in spades.

That assemblage does not appear to be a sentence.

>
>Anyone with a clue considers the facts, not the style stuff, ****wit.

But it is distracting when you choose to code your message content in
the style of an illiterate A-hole. I also think you should have said
"content" rather than "facts." Most of what you have been posting here
recently seems to be opinion rather than fact.

Mark McIntyre

July 9th 06, 12:21 PM

On Sun, 9 Jul 2006 09:30:46 +1000, in alt.internet.wireless , "Rod
Speed" > wrote:

>You have always been, and always will be, completely and utterly irrelevant.

Oh, I've just recognised your name. Conversation over, I don't waste
my time talking to the sort of fool who thinks that because they're
hiding on usenet they can emit language which would get them a severe
slapping in real life.

Nobody cares what you think. Not even you.

*plonk*
--
Mark McIntyre

Rod Speed

July 9th 06, 08:10 PM

xray > wrote:
> Rod Speed > wrote

<reams of your puerile **** flushed where it belongs>

> Most of what you have been posting here
> recently seems to be opinion rather than fact.

Best get your seems machinery seen to then.

Its a fact that even when a receiving antenna does radiate back
half of what it recieves, THAT IS NOT RELEVANT TO WHAT WAS
BEING DISCUSSED, THE LEGISLATED EIRP LEVEL ALLOWED.

Not a shred of opinion involved what so ever.

Oscar Jones

July 9th 06, 08:11 PM

Some terminal ****wit claiming to be
Mark McIntyre >
wrote just the puerile **** thats all it can ever manage.

Rex

July 9th 06, 10:12 PM

On Mon, 10 Jul 2006 04:10:46 +1000, "Rod Speed"
> wrote:

>xray > wrote:
>> Rod Speed > wrote
>
><reams of your puerile **** flushed where it belongs>
>
>> Most of what you have been posting here
>> recently seems to be opinion rather than fact.
>
>Best get your seems machinery seen to then.
>
>Its a fact that even when a receiving antenna does radiate back
>half of what it recieves, THAT IS NOT RELEVANT TO WHAT WAS
>BEING DISCUSSED, THE LEGISLATED EIRP LEVEL ALLOWED.
>
>Not a shred of opinion involved what so ever.
>

Look at this part of the thread...

[John said:]
If the receiver matching is for optimal noise figure, there may be
some reflection and reradiation, but there's nothing pinning it to
be half the received power.

[Roy said:]
John is correct.

[Rod said:]
Nope.

[Roy said:]
A receiving antenna, when matched, reradiates half the power it
receives.

[Rod said:]
Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.

---
So John made a factual statment. Roy agreed. Your opinion was to
disagree with the simple factual statment.

Roy added a clarifying statment. You started to go off the hook and
SHOUT because you were fixated on EIRP. When I read it I never saw any
direct implication about EIRP or legalities in the explanation; it was a
simple explanation about antennas.

Your *opinion* was involved in deciding you knew the exact intent of the
posting and that it had implications in the EIRP thing, just because
that is the interpretation that passed through your mind.

Ok, I'm done here. Not sure why I took the time for this one last post.

Rod Speed

July 9th 06, 10:25 PM

Rex > wrote
> Rod Speed > wrote
>> xray > wrote
>>> Rod Speed > wrote

>>> Most of what you have been posting here
>>> recently seems to be opinion rather than fact.

>> Best get your seems machinery seen to then.

>> Its a fact that even when a receiving antenna does radiate back
>> half of what it recieves, THAT IS NOT RELEVANT TO WHAT WAS
>> BEING DISCUSSED, THE LEGISLATED EIRP LEVEL ALLOWED.

>> Not a shred of opinion involved what so ever.

> Look at this part of the thread...

> [John said:]
> If the receiver matching is for optimal noise figure, there may be
> some reflection and reradiation, but there's nothing pinning it to
> be half the received power.
>
> [Roy said:]
> John is correct.
>
> [Rod said:]
> Nope.

Not about that particular para of John's. I was saying that John was
not correct on the original point about whatever the receiving anntenna
radiates BEING RELEVANT TO THE LEGISLATED EIRP LEVEL.

No opinion there, just fact.

> [Roy said:]
> A receiving antenna, when matched, reradiates half the power it
> receives.

> [Rod said:]
> Yes but that ISNT ANY REAL POWER in the EIRP restriction sense.

> ---
> So John made a factual statment. Roy agreed.

It wasnt relevant to what was actually being discussed,
WHETHER WHATEVER THE RECEIVING ANTENNA
RADIATES HAS ANYTHING TO DO WITH THE LEGISLATED
EIRP WAS ACTUALLY BEING DISCUSSED.

> Your opinion was to disagree with the simple factual statment.

It wasnt an opinion, it was a statement of fact that that
comment John made WAS NOT RELEVANT TO THE
LEGISLATED EIRP LEVEL THAT WAS BEING DISCUSSED.

> Roy added a clarifying statment. You started to go off the
> hook and SHOUT because you were fixated on EIRP.

The legislated EIRP level WAS WHAT WAS BEING DISCUSSED
WHEN JOHN MADE SUCH A SPECTACULAR FOOL OF HIMSELF
RABBITING ON ABOUT WHAT THE RECIEVING ANTENNA RADIATES.

> When I read it I never saw any direct implication about EIRP or legalities
> in the explanation; it was a simple explanation about antennas.

Pity it was a comment made WHEN THE LEGISLATED EIRP LEVEL WAS
BEING DISCUSSED WITH REFERENCE TO THE RECEIVING ANTENNA.

> Your *opinion* was involved in deciding you knew the exact intent of the posting

Wrong again. It is a FACT that John's comment had no
relevance what so ever to what was being discussed,
whether the receiving antenna has any relevance what
so ever to the legislated EIRP level. It doesnt.

> and that it had implications in the EIRP thing, just because
> that is the interpretation that passed through your mind.

Nothing to do with my mind, it was what was being discussed.

> Ok, I'm done here. Not sure why I took the time for this one last post.

Yeah, you just made a VERY spectacular fool of yourself, yet again.

Jeff Liebermann

July 9th 06, 10:33 PM

[misc.consumers.frugal-living dropped from distribution list.]

Roy Lewallen > hath wroth:

>Don K wrote:
>> "John - KD5YI" > wrote in message news:XLQrg.2896$bd4.372@trnddc01...
>>> Rod Speed wrote:
>>>> A receive antenna has no EIRP, it doesnt radiate any real power.
>>> Actually, when properly matched, it radiates half the received power.
>>
>>
>> How do you get that?
>> If the receiver input impedance is matched to the antenna, all the
>> received power is absorbed. There is no reflection. There is no radiation.
>>
>> If the receiver matching is for optimal noise figure, there may be
>> some reflection and reradiation, but there's nothing pinning it to
>> be half the received power.
>
>John is correct. A receiving antenna, when matched, reradiates half the
>power it receives. An impinging field induces current in the antenna.
>This causes radiation, just like the current in a transmitting antenna.
>As it turns out, when the antenna is matched, the amount of power
>radiated equals the amount of power delivered to the load, and that's
>the best you can do. If you'd like a more in-depth and mathematical
>explanation, you can find it in any antenna text, often discussed as
>"scattering".
>
>If a receiving antenna did absorb all the impinging power, it would be a
>lot easier to make a shield or a stealth aircraft.
>
>Roy Lewallen, W7EL

I'm not so sure. I couldn't find any specific references to this
effect in several books I skimmed. Same with internet searches. If
true, then the concept of converting solar power in an orbital
satellite, converting it to microwaves, beaming it down to an antenna
array in the middle of the desert, and converting it back to
electricity, isn't going to work if the array re-radiates half the
power. That's going to ruin quite a few nifty science fiction stories
and innovative business plans.

I also note that the common microwave path analysis calculations don't
take re-radiation into account. For example, if I start with an EIRP
of perhaps XX dBm from a transmit antenna, -YY dB of path loss, and ZZ
dB receive antenna gain, the power delivered to the receiver (ignoring
coax losses) is calculated at (XX - YY + ZZ) dBm without any mention
of the -3dB that would need to be subtracted if half the receive power
is re-radiated from the rx antenna. It would seem that the common
formula and web forms for link calculations are -3dB off.

I trust your judgement in such matters and you have far more expience
than me, but something seems wrong or I'm missing something. Can you
point me to any books or refernences? I just skimmed Chapter 2
(Fundamentals of Antennas) in "Antenna Engineering Handbook" by Jasik
(1961) and found no obvious mention of this effect.

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

John - KD5YI

July 9th 06, 11:40 PM

Jeff Liebermann wrote:
> [misc.consumers.frugal-living dropped from distribution list.]
>
> Roy Lewallen > hath wroth:
>
>
>>Don K wrote:
>>
>>>"John - KD5YI" > wrote in message news:XLQrg.2896$bd4.372@trnddc01...
>>>
>>>>Rod Speed wrote:
>>>>
>>>>>A receive antenna has no EIRP, it doesnt radiate any real power.
>>>>
>>>>Actually, when properly matched, it radiates half the received power.
>>>
>>>
>>>How do you get that?
>>>If the receiver input impedance is matched to the antenna, all the
>>>received power is absorbed. There is no reflection. There is no radiation.
>>>
>>>If the receiver matching is for optimal noise figure, there may be
>>>some reflection and reradiation, but there's nothing pinning it to
>>>be half the received power.
>>
>>John is correct. A receiving antenna, when matched, reradiates half the
>>power it receives. An impinging field induces current in the antenna.
>>This causes radiation, just like the current in a transmitting antenna.
>>As it turns out, when the antenna is matched, the amount of power
>>radiated equals the amount of power delivered to the load, and that's
>>the best you can do. If you'd like a more in-depth and mathematical
>>explanation, you can find it in any antenna text, often discussed as
>>"scattering".
>>
>>If a receiving antenna did absorb all the impinging power, it would be a
>>lot easier to make a shield or a stealth aircraft.
>>
>>Roy Lewallen, W7EL
>
>
> I'm not so sure. I couldn't find any specific references to this
> effect in several books I skimmed. Same with internet searches. If
> true, then the concept of converting solar power in an orbital
> satellite, converting it to microwaves, beaming it down to an antenna
> array in the middle of the desert, and converting it back to
> electricity, isn't going to work if the array re-radiates half the
> power. That's going to ruin quite a few nifty science fiction stories
> and innovative business plans.
>
> I also note that the common microwave path analysis calculations don't
> take re-radiation into account. For example, if I start with an EIRP
> of perhaps XX dBm from a transmit antenna, -YY dB of path loss, and ZZ
> dB receive antenna gain, the power delivered to the receiver (ignoring
> coax losses) is calculated at (XX - YY + ZZ) dBm without any mention
> of the -3dB that would need to be subtracted if half the receive power
> is re-radiated from the rx antenna. It would seem that the common
> formula and web forms for link calculations are -3dB off.
>
> I trust your judgement in such matters and you have far more expience
> than me, but something seems wrong or I'm missing something. Can you
> point me to any books or refernences? I just skimmed Chapter 2
> (Fundamentals of Antennas) in "Antenna Engineering Handbook" by Jasik
> (1961) and found no obvious mention of this effect.
>

Antennas For All Applications by John D. Kraus and Ronald J. Marhefka
Third Edition
Page 746, Paragraph 21-15

"Prec=(Rr/(Ra+Rr))Pa

where

Rr=receiver impedance, ohms
Ra=antenna radiation resistance, ohms

For a perfect match, Rr=Ra, so that

Prec=(Rr/(Rr+Rr))Pa=0.5Pa (W)

and the receiver gets 1/2 the power collected by the antenna. The other half
is reradiated."

Also see "TV and Other Receiving Antennas" by Arnold B. Bailey published in
1950 by Rider Publishing. Beginning on page 235 near the bottom:

"In radio receiving antennas the predominant resistance is, strangely
enough, largely due to the fact that no electrons can move on the antenna
surface *without also sending radio energy back out into space*. So here we
have the paradox of a receiving antenna, having the prime function of
collecting or extracting energy from space, but unable to do so *without
itself returning radio energy of like kind* into space. The amount which it
returns is one-half of the total that it extracts under properly matched
conditions. In a good installation, with the antenna properly connected to
its receiver load, the receiving antenna will be able to *deliver to its
load one-half of the energy* it extracts from the oncoming radio wave but,
by necessity, *must return the other half to free space*. A receiving
antenna, then, is itself a *new source* of radiation. This is not so
surprising, since *any* reflecting surface, as we have seen, establishes a
new source of radiation"

(Note: The emphasis in the book was italics)

Cheers,
John

John - KD5YI

July 9th 06, 11:40 PM

Mark McIntyre

July 9th 06, 11:49 PM

On Sun, 09 Jul 2006 13:33:43 -0700, in alt.internet.wireless , Jeff
Liebermann > wrote:

>[misc.consumers.frugal-living dropped from distribution list.]
>
>Roy Lewallen > hath wroth:
>
>>John is correct. A receiving antenna, when matched, reradiates half the
>>power it receives.

>>If a receiving antenna did absorb all the impinging power, it would be a
>>lot easier to make a shield or a stealth aircraft.
>>
>
>I'm not so sure. I couldn't find any specific references to this
>effect in several books I skimmed.
>
>I trust your judgement in such matters and you have far more expience
>than me, but something seems wrong or I'm missing something. Can you
>point me to any books or refernences? I just skimmed Chapter 2
>(Fundamentals of Antennas) in "Antenna Engineering Handbook" by Jasik
>(1961) and found no obvious mention of this effect.

Scroggie's "Foundations of Wireless", the book I cut my teeth on (and
my father before me...) mentions this in the chapter on Radiation and
Aerials where he describes the reratiation as a fact of great
importance in recieving aerial design.

I think however Rod's final remark is perhaps the most telling - if an
antenna really did absorb all the energy landing on it, there would be
highly curious side effects.
--
Mark McIntyre

Roy Lewallen

July 10th 06, 07:15 AM

Jeff Liebermann wrote:
>
> I'm not so sure. I couldn't find any specific references to this
> effect in several books I skimmed. Same with internet searches. If
> true, then the concept of converting solar power in an orbital
> satellite, converting it to microwaves, beaming it down to an antenna
> array in the middle of the desert, and converting it back to
> electricity, isn't going to work if the array re-radiates half the
> power. That's going to ruin quite a few nifty science fiction stories
> and innovative business plans.
>
> I also note that the common microwave path analysis calculations don't
> take re-radiation into account. For example, if I start with an EIRP
> of perhaps XX dBm from a transmit antenna, -YY dB of path loss, and ZZ
> dB receive antenna gain, the power delivered to the receiver (ignoring
> coax losses) is calculated at (XX - YY + ZZ) dBm without any mention
> of the -3dB that would need to be subtracted if half the receive power
> is re-radiated from the rx antenna. It would seem that the common
> formula and web forms for link calculations are -3dB off.
>
> I trust your judgement in such matters and you have far more expience
> than me, but something seems wrong or I'm missing something. Can you
> point me to any books or refernences? I just skimmed Chapter 2
> (Fundamentals of Antennas) in "Antenna Engineering Handbook" by Jasik
> (1961) and found no obvious mention of this effect.

I could add more references to the ones already mentioned, but you
should be able to find it in most antenna texts. Look in the index under
aperture and scattering cross section. When dealing with path loss
calculations, the effective aperture is used, and this has the
reradiation already accounted for. In fact, the reradiated power has its
own descriptive unit, the scattering aperture. A good and brief
description of these can be found in Kraus' _Antennas_, p. 29ff, and
many other texts.

You're right that the antennas used to receive beamed power will catch
only half of it at best. But many, many business plans have been
developed and billions in stock sold for schemes which are much less
plausible. For starters, how about the current idea of hydrogen "fuel",
"made from water"? (For those not acquainted with the harsh reality of
thermodynamics, it takes more energy to extract hydrogen from water than
you'll get back when you burn it. Charlatans notwithstanding, there's
just flat no way around this little fact.) Then there's SDI. . .

Roy Lewallen, W7EL

John Navas

July 10th 06, 07:30 AM

On Sun, 09 Jul 2006 22:15:00 -0700, Roy Lewallen > wrote
in >:

>You're right that the antennas used to receive beamed power will catch
>only half of it at best. But many, many business plans have been
>developed and billions in stock sold for schemes which are much less
>plausible. For starters, how about the current idea of hydrogen "fuel",
>"made from water"? (For those not acquainted with the harsh reality of
>thermodynamics, it takes more energy to extract hydrogen from water than
>you'll get back when you burn it. Charlatans notwithstanding, there's
>just flat no way around this little fact.) Then there's SDI. . .

The point of hydrogen is a means of energy storage and transmission, not
power generation. Typically the hydrogen will be released from water by
solar or nuclear power. See:
<http://en.wikipedia.org/wiki/Hydrogen_economy>
<http://auto.howstuffworks.com/hydrogen-economy.htm>
>http://www.aip.org/pt/vol-57/iss-12/p39.html>

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
Wi-Fi How To: <http://wireless.wikia.com/wiki/Wi-Fi_How_To>
Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

Invalid@charter.net

July 11th 06, 12:11 AM

On Sat, 08 Jul 2006 16:08:23 GMT, John - KD5YI
> wrote:

>Rod Speed wrote:
>> Geoffrey S. Mendelson > wrote
>>
>>>Rod Speed wrote
>>
>>
>>>>>Is one transmit and the other receive?
>>>>>Or are they both transmit and receive?
>>
>>
>>>>They're normally both transmit and receive.
>>
>>
>>>That's a shame. Here in Israel we are limited to 100mw EIRP, which severly
>>>limits the transmit antenna. There is NO limitation on the receive antenna.
>>
>>
>> A receive antenna has no EIRP, it doesnt radiate any real power.
>>
>>
>
>
>Actually, when properly matched, it radiates half the received power.

True, but it's such a low level as to normally be considered
insignificant. Unfortunately some take that to mean there is none.

If there were none, a Yagi antenna which used all passive elements
save for the driven element would not work. On receive that driven
element plays an active (pardon the pun) roll.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Roger

Invalid@charter.net

July 11th 06, 12:24 AM

On Tue, 4 Jul 2006 21:31:06 +0000 (UTC), (Geoffrey
S. Mendelson) wrote:

>Beverly Erlebacher wrote:
>> I'm confused about this "access point" thing.
>
>An access point is a device with an ethernet port on one side and a wifi
>port on the other. In technical terms it would be called a "bridge". It
>"bridges" two seperate network segments, although in this case they use
>different topologies (100Base-T and WiFi).
>
>> Is that the same as a "router"?
>
>
>The usual WiFi router consists of a four port ethernet hub (LAN ports),
>a seperate single ethernet port (WAN port) and a WiFi access point.
>It is set up to "route" between the single (aka WAN) port and the other
>two ports, the LAN and WiFi. Most of what it does for routing is NAT (network
>address translation) and some sort of IP tunneling.
>
>If you ignore the WAN port and just use the LAN ports, you have a four port
>hub and an access point.
>
>
>> Is it as simple as buying a second router (routers are familiar to me) and
>> just hooking that second router to the first router by cable and that would
>> extend my range by the distance of the cable connecting the two routers?
>
>Yes. Just make sure to use the LAN ports. It would be best to use different
>channels. Most WiFi clients are smart enough to use the channel that is the
>strongest if they have access points on more than one with the same SSID.
>
>Make sure to use encryption. Encryption is NOT to keep your data safe,
>nothing can do that. If someone is intent on accessing your network, WEP
>encryption will not keep them out.

True, but the ones that use the dynamic encryption can do a reasonably
good job along with a firewall and router. The golden rule is
"Nothing is bullet proof"

>
>What it is for is to convince the guy driving down the street looking for an
>open network to send out SPAM, or "share" kiddie porn, to drive on.
>Unfortunately, most users don't even change the SSID of their network, let
>alone set an encryption key.
>

One of the locals mentioned doing a bit of "war driving" around town
just for curiosity. About 80 to 90% of the networks heard were
unencrypted AND over half of those _still_used_
the_default_name_and_PW.
I use hard wired Cat5e in a gigabit network as with the amount of
traffic wireless is just too slow even if it is full duplex.

NOTE I only receive the two amateur radio news groups.
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

>Having tuned in late, if you want to have an open network, look up PublicIP.
>It's a "live cd" that runs on a PII or better (x86) computer and provides
>all the functions you need to offer a secure and safe open network.
>
>Geoff.
Roger

Rod Speed

July 11th 06, 12:34 AM

wrote
> John - KD5YI > wrote
>> Rod Speed wrote
>>> Geoffrey S. Mendelson > wrote
>>>> Rod Speed wrote

>>>>>> Is one transmit and the other receive?
>>>>>> Or are they both transmit and receive?

>>>>> They're normally both transmit and receive.

>>>> That's a shame. Here in Israel we are limited to
>>>> 100mw EIRP, which severly limits the transmit
>>>> antenna. There is NO limitation on the receive antenna.

>>> A receive antenna has no EIRP, it doesnt radiate any real power.

>> Actually, when properly matched, it radiates half the received power.

> True, but it's such a low level as to normally be considered insignificant.

Which is what I said in different words.

> Unfortunately some take that to mean there is none.

The word REAL was used for a reason.

> If there were none, a Yagi antenna which used all passive
> elements save for the driven element would not work. On
> receive that driven element plays an active (pardon the pun) roll.

Having fun thrashing that straw man are you ?

John Navas

July 11th 06, 01:51 AM

On Tue, 11 Jul 2006 08:34:24 +1000, "Rod Speed"
> wrote in >:

wrote
>> John - KD5YI > wrote
>>> Rod Speed wrote
>>>> Geoffrey S. Mendelson > wrote
>>>>> Rod Speed wrote
>
>>>>>>> Is one transmit and the other receive?
>>>>>>> Or are they both transmit and receive?
>
>>>>>> They're normally both transmit and receive.
>
>>>>> That's a shame. Here in Israel we are limited to
>>>>> 100mw EIRP, which severly limits the transmit
>>>>> antenna. There is NO limitation on the receive antenna.
>
>>>> A receive antenna has no EIRP, it doesnt radiate any real power.
>
>>> Actually, when properly matched, it radiates half the received power.
>
>> True, but it's such a low level as to normally be considered insignificant.
>
>Which is what I said in different words.
>
>> Unfortunately some take that to mean there is none.
>
>The word REAL was used for a reason.
>
>> If there were none, a Yagi antenna which used all passive
>> elements save for the driven element would not work. On
>> receive that driven element plays an active (pardon the pun) roll.
>
>Having fun thrashing that straw man are you ?

Take a deep breath. He was more or less on your side.
Not nice to lash out at him too (or anyone for that matter).

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
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Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

Don K

July 11th 06, 01:51 AM

> wrote in message ...
> On Sat, 08 Jul 2006 16:08:23 GMT, John - KD5YI
> > wrote:
>>
>>Actually, when properly matched, it radiates half the received power.
>
> True, but it's such a low level as to normally be considered
> insignificant. Unfortunately some take that to mean there is none.
>
> If there were none, a Yagi antenna which used all passive elements
> save for the driven element would not work. On receive that driven
> element plays an active (pardon the pun) roll.

Still, that's a special case.

I can choose a different special case with a different result.
For a large, high-gain aperture-type antenna such as a big horn or dish,
virtually the received energy orthogonally incident on its cross-section
will be sucked up and absorbed.

Therefore you can't really say that an antenna always radiates at least
half the received power.

Don

John Navas

July 11th 06, 01:54 AM

On Mon, 10 Jul 2006 18:24:27 -0400, wrote in
>:

>On Tue, 4 Jul 2006 21:31:06 +0000 (UTC), (Geoffrey
>S. Mendelson) wrote:

>>Make sure to use encryption. Encryption is NOT to keep your data safe,
>>nothing can do that. If someone is intent on accessing your network, WEP
>>encryption will not keep them out.
>
>True, but the ones that use the dynamic encryption can do a reasonably
>good job along with a firewall and router. The golden rule is
>"Nothing is bullet proof"

Not even in the same universe -- WEP is easily cracked in minutes,
little more than the Emperor's new clothes. Use WPA with a strong
passphrase for any real security.

>One of the locals mentioned doing a bit of "war driving" around town
>just for curiosity. About 80 to 90% of the networks heard were
>unencrypted AND over half of those _still_used_
>the_default_name_and_PW.

Yep ... really bad ... shame on the wireless hardware companies!

>I use hard wired Cat5e in a gigabit network as with the amount of
>traffic wireless is just too slow even if it is full duplex.

Wi-Fi is half duplex.

--
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John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
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Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

Rod Speed

July 11th 06, 03:35 AM

John Navas > wrote
> Rod Speed > wrote
>> wrote
>>> John - KD5YI > wrote
>>>> Rod Speed wrote
>>>>> Geoffrey S. Mendelson > wrote
>>>>>> Rod Speed wrote

>>>>>>>> Is one transmit and the other receive?
>>>>>>>> Or are they both transmit and receive?

>>>>>>> They're normally both transmit and receive.

>>>>>> That's a shame. Here in Israel we are limited to
>>>>>> 100mw EIRP, which severly limits the transmit
>>>>>> antenna. There is NO limitation on the receive antenna.

>>>>> A receive antenna has no EIRP, it doesnt radiate any real power.

>>>> Actually, when properly matched, it radiates half the received power.

>>> True, but it's such a low level as to normally be considered insignificant.

>> Which is what I said in different words.

>>> Unfortunately some take that to mean there is none.

>> The word REAL was used for a reason.

>>> If there were none, a Yagi antenna which used all passive
>>> elements save for the driven element would not work. On
>>> receive that driven element plays an active (pardon the pun) roll.

>> Having fun thrashing that straw man are you ?

> Take a deep breath.

Get stuffed.

> He was more or less on your side.

Duh.

> Not nice to lash out at him too

You wouldnt know what a lash was if it was applied to your lard arse.

> (or anyone for that matter).

You get no say what so ever on whose arse gets lashed either.

John Navas

July 11th 06, 03:37 AM

On Tue, 11 Jul 2006 11:35:37 +1000, "Rod Speed"
> wrote in >:

>[SNIP]

*plonk*

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
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Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>

Oscar Jones

July 11th 06, 05:09 AM

John Navas > wrote:
> On Tue, 11 Jul 2006 11:35:37 +1000, "Rod Speed"
> > wrote in >:
>
>> [SNIP]
>
> *plonk*

Fat lot of good that will do you, you stupid plonker.

Highland Ham

July 11th 06, 11:53 AM

>> One of the locals mentioned doing a bit of "war driving" around town
>> just for curiosity. About 80 to 90% of the networks heard were
>> unencrypted AND over half of those _still_used_
>> the_default_name_and_PW.
>
> Yep ... really bad ... shame on the wireless hardware companies!
========================
You probably mean 'shame on the users' who haven't got a clue.

By the way it is the same situation here in the north of Scotland .
Driving in Inverness you can freely access WiFi points allover town
,from commercial companies to hotels..........but not at locations where
you would expect it ....like 'Starbuck' and bookshops like 'Borders'
Also in California you have to pay for WiFi access at
Starbuck.........must constitute a increasing part of their
income,considering the number of people with laptops.....usually without
a coffee..

I know ,I know ...life isn't a freebee

Frank GM0CSZ / KN6WH

Geoffrey S. Mendelson

July 11th 06, 12:31 PM

Highland Ham wrote:

> By the way it is the same situation here in the north of Scotland .
> Driving in Inverness you can freely access WiFi points allover town
> ,from commercial companies to hotels..........but not at locations where
> you would expect it ....like 'Starbuck' and bookshops like 'Borders'

This will go on until the Scotish police start doing what the English do.
They track traffic at the ISP level looking for "kidde porn". Once they
find it, they locate the person sending or receiving the files.

They have no trouble getting a warrant and come in and arrest the owner of
the account and confiscate their equipment.

As soon as they do this, "users" will go looking for unencrypted
networks and use them, if they don't know I don't know Scotish law, but
in most places the owner of the network is responsible for what is done
with it.

There was a case in Canada of a man found driving five miles per hour
in a residential neighborhood. When the police stopped him, his pants
were around his ankles and there was a laptop on his lap.

Canada unlike most places has a law prohibiting using other people's internet
connections without permission. Most places don't.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

John Navas

July 11th 06, 03:53 PM

On Tue, 11 Jul 2006 10:53:18 +0100, Highland Ham
> wrote in
>:

>>> One of the locals mentioned doing a bit of "war driving" around town
>>> just for curiosity. About 80 to 90% of the networks heard were
>>> unencrypted AND over half of those _still_used_
>>> the_default_name_and_PW.
>>
>> Yep ... really bad ... shame on the wireless hardware companies!
>========================
>You probably mean 'shame on the users' who haven't got a clue.

No, I mean shame on the wireless hardware companies, as I wrote, for
such a gross disservice to their customers -- it shouldn't be necessary
to be an IT expert to use Wi-Fi safely. It should just work properly.
Otherwise it's not ready for the market.

--
Best regards, FAQ for Wireless Internet: <http://Wireless.wikia.com>
John Navas FAQ for Wi-Fi: <http://wireless.wikia.com/wiki/Wi-Fi>
Wi-Fi How To: <http://wireless.wikia.com/wiki/Wi-Fi_How_To>
Fixes to Wi-Fi Problems: <http://wireless.wikia.com/wiki/Wi-Fi_Fixes>