Linksys wusb54gc external antenna modification.

Well, me and my mate decided to modify Linsys wusb54gc for adding an external

antenna. As you probably know - this card has one of the best chipset available

for wardriving purposes - RT2571. Adding an antenna was like a great idea to get

better range, and, you can find a few manuals how to do this on the net. For example here:

http://www.ab9il.net/wlan-projects/wifi5.html

This is how this card looks like:

And this picture presents some statistics from airodump-ng before modification:

This little thing we are going to add:

Now some disclamers:

1. Main parts of a job were done by my friend, the guy who knows a lot about doing such stuff.

2. Everything has been done according to tutorials we have found on the net.

3. Each tutorial states successful result of modification.

4. We have failed.

Anyway, i am presenting here steps we have made, so you can see that i am not just writing

meaningless words.

Ok, first thing, we have to open our card, do it with knife or something sharp.

When you'll be done, here is what you will see:

Next, lets make some space for our small antenna socket, for this we will need to cut our

card a little bit, lets see...

See this red region a have marked? This we are going to cut, there are no circuit and stuff, so

no worries that we are going to break anything. You can use a grinding machine for it for example like we did.

Just 1 minute of work and here we go.

Ok, next we have to do some half holes in a casing, just like on the picture.

Now, main part that we are interested in, picture:

Let me explain:

*1 - actually this is internal antenna, the element, responsible for catching the signal.

Exactly this element we are going to modify. We are going to extend the circuit with an

external antenna socket, previously splitting this circuit - detaching ground from main

inductor.

*2 - not important for us. This part processes the signal.

*3 - Main inductor.

*4 – Ground.

First thing we have to do is to scrape the coating away from (*1) element. Just like on the pic:

Now, cut the circuit stripline in marked place. Another tutorials stands to cut in 2 places -

there is no difference - you simply need to "break the circle" for now, thats all.

To be sure we have succeed, lets check the signal:

As you can see there is no signal - the circuit has been splitted.

*Notice: even if you will now connect this card to a computer - it will be still showing

networks.

*Notice 2: At the end, we have done same thing like here: http://www.ab9il.net/wlan-projects/wifi5.html,

cutted stripline in 2 places. After doing this card no more can show networks, but that is just by

the way. After cutting in 2 places the final result is 100% the same like cutting in just 1 place.

Now, we are going to do some soldering. here is the final result of it:

In a few words, we have taken coaxial cable of 2cm lenght, soldered center conductor of

our socket to a main conductor stripline on our circuit. With cable's ground part we have connected

socket shield and ground stripline. In this way we have recreated the circuit back. By doing so

we have completed the modification. Now putting casing back together, and we got:

Now, i have told that we have failed. You may think - my card now doesnt show any networks.

No. It shows networks, take a look at the picture:

It shows now 7 networks with external antenna. With its original non-modified internal antenna it was showing

11 networks!

* Notice: Linksys wusb54gc has 14 - 17 dBi

Ok, so maybe my antenna is fucked up in any way? No. While writing these words - i got

here, to the left, another wireless adapter - i'll keep its name to myself, its power - 15 dBi.

It has external antenna connection socket. So lets check how many networks we will get with it.

We are connecting same antenna..

Terminal, and whole monitor was not enough to display all available networks, currently you

can see 35 networks! Add around 10 to this number and you'll get 45 fucking networks available

from my damn house! And all this on 15dBi card + 2 dBi antenna.

* Notice: in case of this card, airodump always shows Power = 0 on every network, even my own while

my router + access point are placed around 1 meter away from my laptop.

* Kewl: Imagin' how many networks i will have if i will use Alfa adapter (27dBi) + huge antenna (~18dBi)!

By this i have showed that external antenna is working just nice.

Conclusion: In our case, Linksys external antenna mod has failed, a card now 1.5 times less powerful,

then it was before. So, if you are about to modify your own card - think twice before doing so. I

dont know about these people writing this tuts on the net - have they realy succeed?

Cheers, cross.