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

On 2 jun, 00:46, Larry wrote:
Len wrote in news:de4faa89-476d-416c-87b8-
:

I tried to install MaxSea 10.3.2.1 on a new laptop with W7 Home
Premium.
Installation went fine but it won't run.
Anybody here who found a solution?

Regards,
Len.

Why in hell would anyone buy a new 64-bit Win7 laptop to replace a
perfectly-good-working WinXP (or whatever it was) laptop that MaxSea
10.3.2.1 ran perfectly under?

Is there a motive I missed??

Larry,
It's just a simple story about a laptop reaching the end of its
technical lifetime...
After the screen quit I used a stand alone screen on the vga output.
After the CPU fan began screeming I carefully greased the bearings.
After the keyboard started to give in I replaced that. They are quite
standard, I noticed.
After random stopping and complete and spontaneous restarting I
started to think about a new one.
I now invested 599 dollars in a blazingly fast laptop with a super
16:9 screen that hopefully will last again for 6-7 years...
The only problem was this Windows 7 not running my MaxSea.

In the mean time I discovered that MaxSea 10.3.2.1 does run under
Windows 7 Starter Edition without doing or changing anything.
Virtual PC solved my problem under Windows 7 Home Premium. For those
who are interested: Virtual PC runs on all W7 platforms, excluding the
most basic one.
There is no need to upgrade to Pro or Ultimate or whatever, even if
Microsoft says so.
The proof is on my table...

Regards, Len.

Len wrote in news:08ecb758-f5bf-4ce7-a073-
:

On 2 jun, 00:46, Larry wrote:
Len wrote in news:de4faa89-476d-416c-87b8-
:

I tried to install MaxSea 10.3.2.1 on a new laptop with W7 Home
Premium.
Installation went fine but it won't run.
Anybody here who found a solution?

Regards,
Len.

Why in hell would anyone buy a new 64-bit Win7 laptop to replace a
perfectly-good-working WinXP (or whatever it was) laptop that MaxSea
10.3.2.1 ran perfectly under?

Is there a motive I missed??

Larry,
It's just a simple story about a laptop reaching the end of its
technical lifetime...
After the screen quit I used a stand alone screen on the vga output.
After the CPU fan began screeming I carefully greased the bearings.
After the keyboard started to give in I replaced that. They are quite
standard, I noticed.
After random stopping and complete and spontaneous restarting I
started to think about a new one.
I now invested 599 dollars in a blazingly fast laptop with a super
16:9 screen that hopefully will last again for 6-7 years...
The only problem was this Windows 7 not running my MaxSea.

In the mean time I discovered that MaxSea 10.3.2.1 does run under
Windows 7 Starter Edition without doing or changing anything.
Virtual PC solved my problem under Windows 7 Home Premium. For those
who are interested: Virtual PC runs on all W7 platforms, excluding the
most basic one.
There is no need to upgrade to Pro or Ultimate or whatever, even if
Microsoft says so.
The proof is on my table...

Regards, Len.


Ah, I see....sorry.

--
http://www.goveg.com/feat/agriproces...UStatement.asp
Watch the FULL video. I dare ya! Shechitah barbarians!

Larry