On Thu, 03 Jun 2010 02:00:06 +0000, Larry wrote:

Bruce wrote in
:

No hand phone, or just the old "number's only" cell phone?



USA nationwide service on Verizon Wireless' most complete system, the
best of the best in the USA.....

50 cents per month user fee + 3.6 cents per minute ($US2.16/hour)
prepaid on MVNO system of Pageplus Cellular. No $4000 phone bills, no
bogus fees and charges noone can explain, no Verizon wienies lying to
you every time they open their mouths. NOONE beats Pageplus for service
and price point.

http://www.pagepluscellular.com/

The numbers on this website need to be updated. It used to cost us
5.3c/min, but $80 PINs now get you 2000 minutes for about $72 with the
discounts Callingmart gives us so the price numbers on the webpage are
too high but the concept works great:

http://nordicgroup.us/prepaid/pageplus.html

We must buy "something", even if it's only a $10 payment, within 120
days of the last entry. It's as simple as entering the PIN number we
get from Callingmart.com. We can buy PINs at big discounts when
Callingmart has a sale, then store the PIN on Callingmart until our next
120 days is up....or....you can store the PIN up to a year on
Callingmart's account to use any time you like.

Noone here beats the price point. Verizon has the finest coverage of
any carrier in the USA and Pageplus uses the same system across the
country.

Yep...."just the old "number's only" cell phone". That's me.

No monthly bill....NO FUNNY BUSINESS....No giving back minutes every
month you don't use, which is crazy.

Last month's cellular service cost me less than $11US


You are right down to what us benighted 3rd world residents pay. I use
prepaid refills - the most popular phone scheme in Thailand, and it
seldom costs me US$ 12.00 a month. Usually a bit less.

And I can travel anywhere in the country and the cost per minute is
the same. No long distance changes. Actually, a hand phone is cheaper
then a land line as the land line charges long distance charges for
anywhere outside your local area.

New Subject:

Am in the process of making a wi-fi "dual quad" antenna, two diamond
shaped lobes with the feed line and ground connected at each side at
the center.. . My question is if the actual shape of the lobes is
critical, assuming that the length of the loop is correct. In other
words, if it were two triangles instead of two squares would it make a
measurable difference?


Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Bruce wrote in
:

Am in the process of making a wi-fi "dual quad" antenna, two diamond
shaped lobes with the feed line and ground connected at each side at
the center.. . My question is if the actual shape of the lobes is
critical, assuming that the length of the loop is correct. In other
words, if it were two triangles instead of two squares would it make a
measurable difference?



Wrong thinking. The quad has side and rear reception. Unless you live
in a totally rural (in Bangkok??!! HA!!) area with no other interfering
signals, your enemy is other stations getting into your receiver,
crashing with your packets coming from the node. Quads are for HF,
maybe VHF to 150 Mhz as I had dual 2 meter quads up for years. Wifi is
a microwave band where microwave antennas are king. Waveguide antennas
are far better than any quad at 2.4Ghz. The N band at 5.5 Ghz is even
worse. Every time someone within 5 miles lights off a 2.450 Ghz leaky
microwave oven, your signal is trashed.

Build one of these for almost nothing:
http://www.turnpoint.net/wireless/has.html

Look at the various designs and note the gain and interference figures.
That quad would be 10 meters long in a tin shed to even come close to a
good Pringle's can with the internal flatwasher tuning to set its
bandwidth for only this band.

We're building this one:
http://www.oreillynet.com/cs/weblog/view/wlg/448
His gain measurements are very close to our observations:

Here were the average received signal and noise readings from each, in
roughly the same position:

Antenna Signal Noise
10db A: -83db -92db
10db B: -83db -92db
11db: -82db -95db
24db: -67db -102db
Pringles can
(shotgun): -78db -99db
Pringles can
(internal): -81db -98db

Here's your other enemy:

"The test partner (AP side) signal results were virtually the same.
Interestingly, even at only 0.6 mile, we saw some thermal fade effect;
as the evening turned into night, we saw about 3db gain across the board
(it had been a particularly hot day: almost 100 degrees. I don't know
what the relative humidity was, but it felt fairly dry.)"

That quad would have to be a thousand metres in the air to keep from
seeing the hot buildings and parking lots around it. Night shots are
much less noisy. At 2.4Ghz, the thermal noise is a killer.

Two 12db Pringles cans like his will connect up in flat terrain about 4
km, reliably, if there are no obstructions. Mountain top to mountain
top, 10 km is easy, maybe 15 km is possible.

It's about 1.5km between my public hotspot with a 3db omnidirectional
antenna running 200mw ERP up 10 meters inside an inverted plastic bucket
to keep the rain off my router on Channel 6, to the Pringle's antennas
on top of the enlisted barracks at the Air Force Base. Except in rain
storms, which suck up 2.4Ghz like a carbon sponge, the boys have a
nicely usable signal over that path. There isn't much interference
because I'm across the street from the base and the Air Force doesn't
trust wifi for its own stuff, of course, so that keeps them off the air.
Works great...(c;]



--
Creationism is to science what storks are to obstetrics.

Larry

On Thu, 03 Jun 2010 15:55:43 +0000, Larry wrote:

Bruce wrote in
:

Am in the process of making a wi-fi "dual quad" antenna, two diamond
shaped lobes with the feed line and ground connected at each side at
the center.. . My question is if the actual shape of the lobes is
critical, assuming that the length of the loop is correct. In other
words, if it were two triangles instead of two squares would it make a
measurable difference?



Wrong thinking. The quad has side and rear reception. Unless you live
in a totally rural (in Bangkok??!! HA!!) area with no other interfering
signals, your enemy is other stations getting into your receiver,
crashing with your packets coming from the node. Quads are for HF,
maybe VHF to 150 Mhz as I had dual 2 meter quads up for years. Wifi is
a microwave band where microwave antennas are king. Waveguide antennas
are far better than any quad at 2.4Ghz. The N band at 5.5 Ghz is even
worse. Every time someone within 5 miles lights off a 2.450 Ghz leaky
microwave oven, your signal is trashed.

Build one of these for almost nothing:
http://www.turnpoint.net/wireless/has.html

Look at the various designs and note the gain and interference figures.
That quad would be 10 meters long in a tin shed to even come close to a
good Pringle's can with the internal flatwasher tuning to set its
bandwidth for only this band.

We're building this one:
r
His gain measurements are very close to our observations:

Here were the average received signal and noise readings from each, in
roughly the same position:

Antenna Signal Noise
10db A: -83db -92db
10db B: -83db -92db
11db: -82db -95db
24db: -67db -102db
Pringles can
(shotgun): -78db -99db
Pringles can
(internal): -81db -98db

Here's your other enemy:

"The test partner (AP side) signal results were virtually the same.
Interestingly, even at only 0.6 mile, we saw some thermal fade effect;
as the evening turned into night, we saw about 3db gain across the board
(it had been a particularly hot day: almost 100 degrees. I don't know
what the relative humidity was, but it felt fairly dry.)"

That quad would have to be a thousand metres in the air to keep from
seeing the hot buildings and parking lots around it. Night shots are
much less noisy. At 2.4Ghz, the thermal noise is a killer.

Two 12db Pringles cans like his will connect up in flat terrain about 4
km, reliably, if there are no obstructions. Mountain top to mountain
top, 10 km is easy, maybe 15 km is possible.

It's about 1.5km between my public hotspot with a 3db omnidirectional
antenna running 200mw ERP up 10 meters inside an inverted plastic bucket
to keep the rain off my router on Channel 6, to the Pringle's antennas
on top of the enlisted barracks at the Air Force Base. Except in rain
storms, which suck up 2.4Ghz like a carbon sponge, the boys have a
nicely usable signal over that path. There isn't much interference
because I'm across the street from the base and the Air Force doesn't
trust wifi for its own stuff, of course, so that keeps them off the air.
Works great...(c;]


Interesting. The "double quad's all use a reflector which greatly
attenuates interference from the back side of the antenna.

What I'll do is build one of each and see :-)

Thanks for the idea.
Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Bruce wrote in
:

What I'll do is build one of each and see :-)

Thanks for the idea.
Cheers,



Screwing around with wifi is almost as much fun as ham radio used to be....
(c;]

They used to make an aluminium dish for the kids to slide downhill in the
snow called a snow coaster. It had two handles to hang onto and was
relatively concave shaped until it hit its first good rock.

We've acquired a good one, nearly unused. If you lean it against something
on the lee side of the internally-antenna'd netbook, you can move the
netbook around while watching the signal level to find where the signal
reflects off the metre-wide aluminum dish as a reflector, concentrating the
signal from a distant hotspot into the behind-the-screen wifi antennas.

Even if it didn't work so great, and it does, the looks you get from
passersby more than make up for any deficiencies in RF effects....(c;]

Maybe the passersby have noticed the CIA official logo we put on the back
of it and think we're government spies....hee hee.

--
Religion is to reality what homeopathy is to medical science.

Larry

On Fri, 04 Jun 2010 01:07:36 +0000, Larry wrote:

Bruce wrote in
:

What I'll do is build one of each and see :-)

Thanks for the idea.
Cheers,



Screwing around with wifi is almost as much fun as ham radio used to be....
(c;]

They used to make an aluminium dish for the kids to slide downhill in the
snow called a snow coaster. It had two handles to hang onto and was
relatively concave shaped until it hit its first good rock.

We've acquired a good one, nearly unused. If you lean it against something
on the lee side of the internally-antenna'd netbook, you can move the
netbook around while watching the signal level to find where the signal
reflects off the metre-wide aluminum dish as a reflector, concentrating the
signal from a distant hotspot into the behind-the-screen wifi antennas.

Even if it didn't work so great, and it does, the looks you get from
passersby more than make up for any deficiencies in RF effects....(c;]

Maybe the passersby have noticed the CIA official logo we put on the back
of it and think we're government spies....hee hee.


Over here you just go down to the market and buy a "wok". I have no
idea what the largest size made is but a 26 incher is right off the
shelf. Works a treat but my wife doesn't think that they create a
suitable ambience hanging on the living room wall :-)


Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Bruce wrote in
:

Over here you just go down to the market and buy a "wok". I have no
idea what the largest size made is but a 26 incher is right off the
shelf. Works a treat but my wife doesn't think that they create a
suitable ambience hanging on the living room wall :-)



What could be more beautiful than a microwave dish pointed at a really
nice, really fast wifi hotspot?

If you want to fool around with a wok, point it at the sun and take a
piece of paper and find its focal length, where the sun focuses and
burns a hole in the paper. Sorta measure the distance from the center
of the wok to the paper (without burning your fingers, please). At that
distance from the wok, which we may assume is sort of a truncated
sphere, point the open end of the pringle's cantenna into it and rig up
a coathanger wire mount to hold the pringle's cantenna in position,
running the coax up the vertical wire to the top of the dish before
routing it away to the computer.

This increases the capture area from the hole in the end of the
pringle's can to an effective hole the size of the outer diameter of the
wok, the bigger the better. It's NOT a good idea to point this beast at
any nearby wifi radiating transmitters as it may blow the receiver front
end out of the computer. Don't blame me, in other words.

This is a powerful antenna, now, and you wifi transmitter has now become
nearly a ray gun. I'm not sure how much gain that would have but I'd
bet it would be in the 30db area. The pringles cantenna is narrow
enough that it would receive very little back radiation from around the
edges of the dish, so if the dish is kept in the shade, not in the sun
cooking eggs, the thermal noise floor would be quite deep, increasing
its effectiveness even more. Now you've got a small S-band point-to-
point microwave antenna any woman should be proud to display to her
astonished friends on the couch....(c;]

Try not to burn any holes in the wall or irradiate the neighbors' kids.

--
Religion is to reality what homeopathy is to medical science.

Larry