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Old 01-19-2005   #7 (permalink)
Thorn
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Join Date: Apr 2002
Location: Villa Straylight
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Quote:
Originally Posted by humdinger
Firstly, can anyone spot any major flaws in the above two options, or point out a solution that I may have missed.
No major flaws. You've pretty much nailed it.

Quote:
Originally Posted by humdinger
Secondly - would it be possible to use a Yagi or Parabolic antenna indoors and sweep the building from my desk? Or would I have to wander around juggling a laptop and large antenna?
It's possible, but large antennae are better for exterior sweeps. A 24dBi dish is about 2ft. across. It's a bit awkward to be swinging one of those.

Quote:
Originally Posted by humdinger
Thirdly - It would appear that both the Yagi and Parabolic antennas offer very focused beams, is one more ideal than the other for this type of use?
For interior sweeps, use either a laptop and low-gain Yagi (~10dBi or less) on "mailroom" type cart (I like the Rubbermaid models - less metal to throw signals off) or a Pocket PC and a low-gain Yagi.

Quote:
Originally Posted by humdinger
Forthly - Is it possible to attach an external antenna to a PDA with a compact flash or SD I/O card based wireless adaptor? If so, which adaptor would you recommend?
It's possible, but it means cracking the case and adding cabling and connectors yourself; ugly but it works. You'll have to have some minimal skills with a soldering iron and electronics to do it. Check Google, I've seen one HOWTO for a CF card, but don't recall the address.

Quote:
Originally Posted by humdinger
Finally - Could I use the PDA in such a manner, whereby once I detect a wireless access point I could then dampen the field (by wrapping it in a foil bag). I could then use this limited range to help me get a better idea of where exactly the access point is located (using the logic - if it detects it whilst the signal is dampened then it must be close).
From experiments I've found that a Mylar-coated snack bag (e.g. Lay's Potato Chips) will consitantly attenuate the signal about 7 to 8dBm. Chris, myself and the other WarDriving Contest staff members used this exact method for the RunningMan Mini-Game at DefCon12. http://www.blackthornsystems.com/ed_runningman.htm This was the reverse application of what you want to do, but it works both ways.
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Thorn
"I'm The Doctor. I'm a Time Lord. I am from the planet Gallifrey in the constellation Kasterborous. I'm 903 years old and I am the man who is going to save your lives and all 6 billion people on the planet below... You got a problem with that?"

Last edited by Thorn : 01-19-2005 at 08:52 AM.
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