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Possible idea for diy antenna


Painkiller667

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here is my adapter. Its the naked airnet awu108.

http://www.flickr.com/photos/30208246@N00/316151102/

here is the possible antenna

http://www.flickr.com/photos/30208246@N00/316151106/

another pic of the antenna showing the tip(jack)

http://www.flickr.com/photos/30208246@N00/316151104/

and finally, how it looks like if i just slip it on.

http://www.flickr.com/photos/30208246@N00/316151107/

The antennas are the old cellphone antenna and a cut out bottom of a soda can. Call me a noob, and you would be right, but it sure does look fine the way i set it up. Maybe the frequencies of the adapter's antenna, which btw, i found out the model of the antenna to be MS-156NB, are different than the cellphones, but they sure do fit right into eachother. I was also thinking of getting a sma cable if this doesnt work out, and soldering the sma onto the chip. I also have a crazy question/idea. What if you take an ordinary antenna that comes standard with a tv that you buy, and you plug that jack into the cable you had mounted onto the usb. Anyway, if both ideas are fucked up then please enlighten me. Thank you. :)

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i think the TV antenna might work BUT me and my friends have converted an old satellite dish *the direct TV ones, NOT the big ones* in to a wireless antenna. This design only works when you know where is wi-fi is coming from because it is VERY uni-directional, but it helps to steal wi-fi from the guy down the road. all it requires is some modification to the transmitter head

***

engadget.com

awsome PDF full of info

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but it is totally different from the directv dish because the directv, you just use it for the parabolic shape; you put the usb adapter in the holder and its done. I meant those antennas that look like / the ones that come with new televisions. They have the tv jack and I was wondering if it was possible to get a connector for my MS-156 antenna on my usb adapter to connect it to a tv jack. So that I could just plug my usb into a tv antenna and use it. First main question is if it is possible to find such a converter: ms-156 to (whatever the tv jack is called). And the second question, is if the tv antenna is going to pick up the right signals.

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I also have a crazy question/idea. What if you take an ordinary antenna that comes standard with a tv that you buy, and you plug that jack into the cable you had mounted onto the usb.

You don't want to do that unless you are certain that the antenna will resonate on the frequencies your Wifi uses. If you have an unbalanced antenna with the transmitter, you could backfeed back into the transmitter and see the magic smoke in a short matter of time.

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What would be cool is to build a cantana out of a metal garbage can.

Now THAT needs to be done :D How the hell would you mount it, though? You'd need a pretty large amplifier to drive it too....

Actually, no....it's a common misconception that the size of antenna delegates how much power drives it. As long as it is RESONANT on the frequency that it operates on, it can be as big as you want.

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well, now that i scanned for networks from my house with a usb adapter and a parabolic antenna, I know which ones are closer to me and where they are located. I think now I need to get a cantenna to focus on that one signal thats best for me to connect to. I found that parabolic antennas are for general signal strengthening and signal searching while cantennas are best for focusing on one access point and are sensitive to position, so ill just point the cantenna to one access point and get even stronger signal than the parabolic antenna.

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Sounds like you need to calibrate your parabolic dish a bit better,

For a start you should have a directional feed which goes directly towards the center of the dish - a cantenna would do this perfectly. The distance between the dish and the feeder is very important and to get optimal performance you need to do some equations to get the distance just right. You'll also need to do some equations on the feeder too so that signals from the entire dish are being recieved optimally.

An omnidirectional (such as the ones built into USB cards) are not really suitable for use with a parabolic dish due to their omnidirectional nature. Most of the signal reception will not be from the dish at all, rather from areas in front of the dish and to the sides of it.

Check out this link:

http://www.qsl.net/ki7cx/wgfeed.htm

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I found that parabolic antennas are for general signal strengthening and signal searching while cantennas are best for focusing on one access point and are sensitive to position, so ill just point the cantenna to one access point and get even stronger signal than the parabolic antenna.

Right, and you should never transmit out of a modified parabolic antenna....it was built for receive only operation, and quite possibly, the electronics in it don't consist of any transmitting parts..

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Right, and you should never transmit out of a modified parabolic antenna....it was built for receive only operation,

That is true. However, you are able to modify them for 2-way operation. Hams have been doing it for years. The old c-band ones are being modified and used by hams to bounce signals off the moon! One day I will have mine converted and have the radio to do just that.

and quite possibly, the electronics in it don't consist of any transmitting parts..

That is correct if you are trying to use the original hardware. That is why you need to modify the antenna for 2-way use. I will be using 2 for a link to operate an APRS gateway station.

stormadvisor

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The point you point it out as antenna connection is in real live just a messering point and not a antenna connection.

316151102_df1ac97e2c.jpg

The real antenna is the grey looking block that mounted under the print board number.

By removing this and soldering on that point your external antenna lead you have a better connection to the outside world if your antenna is a good working antenna with a good VSWR for this freq:

:wink:

Gerard

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Right, and you should never transmit out of a modified parabolic antenna....it was built for receive only operation,

That is true. However, you are able to modify them for 2-way operation. Hams have been doing it for years. The old c-band ones are being modified and used by hams to bounce signals off the moon! One day I will have mine converted and have the radio to do just that.

and quite possibly, the electronics in it don't consist of any transmitting parts..

That is correct if you are trying to use the original hardware. That is why you need to modify the antenna for 2-way use. I will be using 2 for a link to operate an APRS gateway station.

stormadvisor

I know, I am a ham too :-) I was speaking in terms of modifying it with no transmit equipment present.

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By removing this and soldering on that point your external antenna lead you have a better connection to the outside world if your antenna is a good working antenna with a good VSWR for this freq:

Oh how I cannot stress the importance of VSWR. Gerard is reinforcing what I am trying to say. Basically, if it isn't calibrated for the frequency you want it to transmit on...it will work like crap.

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What would be cool is to build a cantana out of a metal garbage can.

Now THAT needs to be done :D How the hell would you mount it, though? You'd need a pretty large amplifier to drive it too....

Screw the garbage can, I will get a 10 foot parabolic dish! I'll get a pickup truck and mount it in the back, it shouldn't look too suspicious! :-)

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