Hi Freak Antennna - WiFi That Is

Any Black Magic types out there?

Black Magic as in Antenna Design?

I am goofing around with this WiFi Internet thing.

Hey, it's like being a Hammie all over again!

Here is a commericial antenna I bought.
2.4 gah gah ga gig.

Of course I had to hack.

Can I just resize everything by two and get 4 times the gain?

Interesting reflector plate.
You can see the traces on the back side showing thru.

This guy says 6 db,m but I have my doubts.
It is directional, which helps. Not just a stick picking up every cell phone in town.



Here is the schematic if anyone wants a cool 35 dollar tenna for cheap, just wait for wifi to come to a town near you.

Next stop is the big parabolic.
The guy looked worried when I pointed and said "That!"

schematic- 1/32 inch thick pc board.

No rG59! Must be low loss 2.4 gig pipe.

http://vacuumbrain.com/The_Lab/TA/WiFi/wifi_b.jpg

Note the sneaky weird delay tactics with the smaller hot trace:



So the question is how can I DIY a 24 db WiFi grabber?

Thanks!

You can add more panels with exactly the same dipoles on it and feed them in phase. That's what an F-16 radar antenna looks like. Dozens of those.

But the feedline loss as you get further away from the main coax negates the additional antenna gain.=)

I think a Pringle's can with a dipole in it is the approved hacktenna.

The area where there is trace on both board sides of dipoles is the coupling capacitor.

1-3pf

Tapering hot trace is impedance conversion from 50 ohm to 300 ohm to feed 4- 75 ohm dipoles.

teflon coax or forget it!

Pringle's can with a dipole

absolutely. I've seen folks driving around finding open networks with those..

Larry, that is awesome info on that inocent looking thing.
I should have know about the capacitance, Langevin uses the same trick on the AM 16 board, from the in to out iron.

Cool on the Pringles can, but what does the dipole thing look like and how does the coax get hooked up?
Shield goes to the pringles can, or is the can just a reflector/selector?

That dipole may have a diode inside the stinger?
But then, how would it transmit?

You an use some of these antenna layout tricks on audio, for chassis layout food for thought.

Thanks for all the info.

The guy at Express Nets says I would be bumping everybody off line if I hooked up a 1oo KW SSB repeater station to the parabolic.

Hey, I could charge the hood for service!

Does TI make a 2.4 gig chip?
Has to be TX/RX.

I have a rat shack HDTV antenna taken apart and hacked if anyone is interested.
It has a little 6 pin SSD chip in there, phantom power fed thru the coax.

that 2.4 gig coax is $$$ per foot!

Here is the Pringle's can shootout:
http://www.turnpoint.net/wireless/has.html

2Ghz is about as high as you can use normal glass epoxy as a dielectic. Then you go to teflon pcb material above that.

Great link!
You just save me $150 on a parabola, and another $150 on the amp.

The coffee can works great!

Increased download time from 70 kb/sec to 140 kb on a sample load.

You turn it 180, and all loading stops.

I will Post a Picture of Pathetic DIY Parabola that Peter Purpose Picked in between Pork Pies at the Pub.

:grin:

(built before Lar's post.)

Now point the can into a DirecTv dish and lookout!

I recieved a free Terk 2.2 ghz from the freak next door when he went Comcast.
Put it up on a a surf casting outfit that was also given to me so from the second story balconey, I got that sucker up there about 30 feet..
I am reeling in the stations, yessir.
Put a mirror on the couch, grab the surf reel, twist the mast til you get channel 9.
Manual TenaRotor, if anyone remembers those.



It works great for TV. So now the I gots free TV and free internet.
All because of DIY.
Got rid of the phone I was so happy.

Saving about 100 a month between no cell, no phone, and no cable.

Once I get this can finalized, it can go up there with the Terk.

So now I am ready for the next rent increase.
:twisted:

[quote author="Larrchild"]Now point the can into a DirecTv dish and lookout![/quote]

Yes.
At work, my computer is far from the main wireless transmitter, so by putting my remote antenna inside an old TV antenna dish and pointing it in the right direction......gets me a strong signal....up two bars.

=FB=

Hi CJ,

Whats your need and plan for WiFi? I have a little experience with it. For work I tend to throw 802.11b offshore 20 miles to ships. It is funny to get a call at 3am from some scientist who cann get to eBay.

Parabolas are difficult to aim at any distance by the way.

-E

OK, I have been around the block with every DIY wifi antenna you can name, and went back to the stock di-pole hailed up a tree.

Why?

If you use a directional antenna, like a high dollar parabolic dish, you are now locked in to that one transmission node. So you have no redundancy.
Right now, I am picking up 100 percent signal strength on 6 of the 8 Google WiFi gateways, with a crappy ol Buffalo air station.
So cheaper, the better.
Dont waste your money on a NetGenius hi tech antenna and a 5 megawatt transmitter.

With microwave, (which is what 2.4 Ghz is,) it is very line of sight, and very weather related.
So you want to be able to shift around and connect to different nodes, as things change.

Location Location Locatio.
Same as real estate. Thats what wifi is all about.
Siganl to noise, and IP popularity.

Now I need to bootl3eg a POE box. I do not like running 120 vac into a dry redwood tree.
I need 5 volts at the end of a 60 foot cat 5 cable.
Anybody ever do it?
Different modes, depending onthe speed of the network card.
I tried last nigth, but no luck.
Its kind of like pphantom power.
Heres is a Wikpedia exazmple:
Homebrew:

Commonly just wires the spare pairs 4-5 (positive) and 7-8 (negative) to an appropriate DC power source. Issues like wire resistance and maximum current have to be calculated. In many countries there are regulations for voltages above 50 V to be considered.

Example: Linksys WRT54G (12 V, 1 A) fed over 10 m Cat 5 cable (AWG 24, 0.2 mm²). The cable resistance will be 0.8 Ω, the resulting voltage drop 0.8 V. As the Linksys converts the voltage to 5 V internally this drop is not critical and the installation will work fine.
[edit] Notes

Now I need to bootl3eg a POE box. I do not like running 120 vac into a dry redwood tree.
I need 5 volts at the end of a 60 foot cat 5 cable.

Click to expand...

Use a pair of 6 or 12v xfmrs back to back for proper "Class II" wiring, up the tree. 120>6.3-----6.3<120 vac ...use speaker wire.

Nice!
31 mm, right? N or S?


1 5/8 inches from the back?
Yuban give 1/2 db extra.

Only problem with those, great reception, but transmitting sucks all of your 100 mw of power. Goes into the can, not the air.

Larry, nice idea.
a 100 ma xfmr won't break the fishin line.

Do I need a blinking red LED on top for the airplanes?

24v doorbell xfmrs would allow thinnest wire gauge, actually.

Weird how they turn four pairs intp a tunerd circuit.
Kind of like the API tramsformer/

Lots of stuff on the net about PoE.

I was thinkin solar panel, b8ut the guy says they get too hot, whatever that means.
Then a repeater, down the tree. But then the whole neighborhood....but what do I care?

There are two 75 ohm resistors ON THE lan CARD that go to a pair, i DO NOT KNOW WHAT THE DEAL IS THERE.
Interesting, CAT 5 means 5 twists per inch:

http://bugclub.org/beginners/networking/cat5.html

[quote author="CJ"]Nice!
31 mm, right? N or S?


1 5/8 inches from the back?
Yuban give 1/2 db extra.

Only problem with those, great reception, but transmitting sucks all of your 100 mw of power. Goes into the can, not the air.

[/quote]

http://seattlewireless.net/index.cgi/BuildingYagiAntennas

I've been installing WiFi stations on the Oregon Coast for the last few years. I'll be running out on thursday to put in another one near Newport. I'm using 14 dBi 120 degree sector panels ($150) and an amplifier. I really recommend these amps. You get power on the transmit side and gain on the receive side. They run around $170 each.

You are allowed up to 4 watts ERP in unlicensed mode. So with a 1 watt amp and a 6dB antenna you are legal. The bonus is the (antenna and amp) 21 dB receive gain.

I'm sending Wifi out to research vessels limited by the curvature of the Earth. Thats 21 miles....Nautical miles that is.

Take a look at hyperlink technologies site.

I tend to use LMR400 cable. But when ever possable I use an outdoor amp next to the antenna with the power injector next to the WiFi card.

Thanks EVM!

tHE GUY DOWN AT eNPRESS nETS (THEY DO WORK IN pORTLAND) RECOMENDED THIS.
hAVE YOU USED IT?

http://www.doubleradius.com/Engenius-2-4-GHz-54-Mbps-Access-point-with-9-dBi-Integrated-antenna?sc=2&category=2813

The ship to shore stuff sounds tuff, camt use a parbolic becuase it is too directional?
The do reach out there.

Never Used that one. Most of our stuff is on the coast and exposed to salt air. We tend to get industrial strength hardware.

I have however set up wireless for my yacht club. Using a 1 watt amp and a 6 dB omni I can cover the entire moorage about 600' by 600' and all of the Columbia river for a mile or so up and down stream.

As for boats. The rolling tends to limit higher gain antennas. A 15 dB omni has a 8 degree vert pattern. So if you roll the boat 4 degrees you lose 3 dB. And you never quite know where they will be. Shore side the 120 degree 14 dB sectors work well.

As for parabolas I have a pair of 24 dB. They are a bear to aim. You best bet in aiming this is to hook up a spectrum analyzer to one and have a strong signel at the other side. Then you can adjust in vert and horiztal until you have the best signal. Then go to the opposit site and do the same.

I go for wider beam widths and more power. Makes life easier.