Your opinion on attennas

Chris_Schear · 09-08-2002

I've read almost every link I've found on constructing homebrew antennas; pringles cans, coffee cans, etc. I even read the http://www.turnpoint.net/wireless/has.html link that compares different types of cans. What I'm interested in is given your personal experimentations with external attennas, which you have found the most usefull for WarWalking.

Now, just because a particular type of can might give you the greatest range, it might be akward walking around the office parks with a 500 gallon drum you've constructed an antenna with and stapped onto your back with industrial strength nylon. So, from a corporate network security persepctive, if your mission is to seek out and SPECIFICALLY isolate where wireless access points lie - which can/antenna do you think is best suited for the job? The goal is to be able to essentially "point and click", and find/walk up to rogue access points.

Thoughts?

I'm inclined to think a can with a narrow diameter is best suited, so that it may be "aimed" more accurately. The last thing I want to do is walk around 9-some odd, 30+ story buildings..."guessing" at where rogue access points are located.

Eyecannon · 09-08-2002

Now that would be cool, if you could get GPS to work inside a building... you could use the elevation info available to map out a 3d path of where you were in the building

Anyway, different antennae do different things... one guy recently used a panel antenna in his backpack with some good results... I have been thinking of using my magmount in a backpack (hopefully it won't kill me!) It might be a little weird if you were walking around a building with a cantenna aiming it all over the place

rogerRabbit · 09-08-2002

You want directionality and, as you're interested in tracking down a site rather than maintaining a useable (hand-held) link, probably as much of it as you can get. By the sound of it, discretion is not an important factor for you

.

Using a cantenna, I'd go for a diameter of circa 3.75" and a length of at least 15". The diameter is more or less a given for 802.11b frequencies and the relatively longer length gives a higher gain/narrower beam. A shorter length (e.g. 6") makes isolating sources a slower process with low-rise buildings. I haven't tried with high-rise, but I'm sure I wouldn't be able to get a good guess, externally, as to a range of floors with just 6".

Chris_Schear · 09-08-2002

What I need to construct is an antenna what I can "aim" and walk. Stand somewhere, recieve a signal from an AP...slowly turn and determine what direction the signal is strongest from, hopefully indicating what direction the AP is.

"By the sound of it, discretion is not an important factor for you."

- No, it isn't...but I don't want to be lugging around some huge can, if some soup can will do the job

Eyecannon · 09-08-2002

Soup can is too short... but lots of people use pringle's cans!

Chris_Schear · 09-08-2002

Given your recommendation of lengths, I'm thinking a Pringles can is the way to go.

rogerRabbit · 09-09-2002

Quote:

Originally posted by Chris_Schear
Given your recommendation of lengths, I'm thinking a Pringles can is the way to go.

Too narrow! Solder/conducting tape three cans of the correct diameter together.

az2k · 09-10-2002

A regular soup can is too short but the larger Campbells can (family size or something like that ) is OK. It is the same size as the Hunt's pasta sauce can shown at turnpoint.net I made a cantenna using the Hunt's can and it works very well. The can is on the short side based on its diameter of 3.25" but it works.

Keith

Sh00t3r · 09-10-2002

The best results i've attained through warwalking is using my home brewed omni and then switching to the pringles can for a more directional view. Seems to work good.

Chris_Schear · 09-10-2002

Thanks for the feedback.

astcell · 09-23-2002

Let's say you're out at the Block at Orange where there are plenty of hi rise office buildings around. Of you are in NYC. If you had a good yagi, could you conceivably point it at all the windows on the buildings, all 40 floors maybe, and get any APs that may be out there? Or do they broadcast enough so that being at the ground floor would pick them up?

I'm trying to figure out the best way to stumble when hi rise office builsings are involved, surely there may be plenty of APs in those!

blackwave · 09-23-2002

Quote:

Originally posted by astcell
I'm trying to figure out the best way to stumble when hi rise office builsings are involved, surely there may be plenty of APs in those!

two words,
bungee cord
helmet optional

RaVenCorax · 09-23-2002

why use a soup can or a pringles can i know some one you know does sheetmetal its not that hard to make a perfect cantenna just give em the dimensions and a few dollars stainless with mounts and predrilled holes

astcell · 09-23-2002

I agree! THe plans I have see online for Pringles antennas are vague in the parts listing. "2 inches all-thread" is not really an item by that name, you need more info!

I would love to see a difinitive parts list, just like turning your AR-15 into an M-16. Information overload baby, that's the name of the game.

I wonder if offering a reward for a 50db antenna would be a challenge to anyone, and what $ amount would entice folks...

RaVenCorax · 09-24-2002

sinve people are always bitchong and going on about pringles can no being metal and soup cans to short make your own or pay someone to make the perfect aize what is it 3.75 inches and 16 in long

yellow pages peoples

09-08-2002	#1 (permalink)
Chris_Schear Packetmonkey Join Date: Aug 2002 Location: WDM, Iowa Posts: 243	Your opinion on attennas I've read almost every link I've found on constructing homebrew antennas; pringles cans, coffee cans, etc. I even read the http://www.turnpoint.net/wireless/has.html link that compares different types of cans. What I'm interested in is given your personal experimentations with external attennas, which you have found the most *usefull* for WarWalking. Now, just because a particular type of can might give you the greatest range, it might be akward walking around the office parks with a 500 gallon drum you've constructed an antenna with and stapped onto your back with industrial strength nylon. So, from a corporate network security persepctive, if your mission is to seek out and SPECIFICALLY isolate where wireless access points lie - which can/antenna do you think is best suited for the job? The goal is to be able to essentially "point and click", and find/walk up to rogue access points. Thoughts? I'm inclined to think a can with a narrow diameter is best suited, so that it may be "aimed" more accurately. The last thing I want to do is walk around 9-some odd, 30+ story buildings..."guessing" at where rogue access points are located.

09-08-2002	#2 (permalink)
Eyecannon Ward River Join Date: Aug 2002 Location: Santa Monix Posts: 679	Now that would be cool, if you could get GPS to work inside a building... you could use the elevation info available to map out a 3d path of where you were in the building Anyway, different antennae do different things... one guy recently used a panel antenna in his backpack with some good results... I have been thinking of using my magmount in a backpack (hopefully it won't kill me!) It might be a little weird if you were walking around a building with a cantenna aiming it all over the place __________________ No, officer, YOU are under arrest! http://eyecannon.com/wardrive.html

09-08-2002	#3 (permalink)
rogerRabbit Peripatetic Stumbler Join Date: Jun 2002 Location: Motueka Posts: 219	Re: Your opinion on attennas You want directionality and, as you're interested in tracking down a site rather than maintaining a useable (hand-held) link, probably as much of it as you can get. By the sound of it, discretion is not an important factor for you . Using a cantenna, I'd go for a diameter of circa 3.75" and a length of at least 15". The diameter is more or less a given for 802.11b frequencies and the relatively longer length gives a higher gain/narrower beam. A shorter length (e.g. 6") makes isolating sources a slower process with low-rise buildings. I haven't tried with high-rise, but I'm sure I wouldn't be able to get a good guess, externally, as to a range of floors with just 6".

09-08-2002	#5 (permalink)
Eyecannon Ward River Join Date: Aug 2002 Location: Santa Monix Posts: 679	Soup can is too short... but lots of people use pringle's cans! __________________ No, officer, YOU are under arrest! http://eyecannon.com/wardrive.html

09-10-2002	#10 (permalink)
Chris_Schear Packetmonkey Join Date: Aug 2002 Location: WDM, Iowa Posts: 243	Thanks for the feedback. __________________ Regards... http://packetmonkey.net

09-08-2002	#4 (permalink)
Chris_Schear Packetmonkey Join Date: Aug 2002 Location: WDM, Iowa Posts: 243	What I need to construct is an antenna what I can "aim" and walk. Stand somewhere, recieve a signal from an AP...slowly turn and determine what direction the signal is strongest from, hopefully indicating what direction the AP is. "By the sound of it, discretion is not an important factor for you." - No, it isn't...but I don't want to be lugging around some huge can, if some soup can will do the job

09-08-2002	#6 (permalink)
Chris_Schear Packetmonkey Join Date: Aug 2002 Location: WDM, Iowa Posts: 243	Given your recommendation of lengths, I'm thinking a Pringles can is the way to go.

09-10-2002	#8 (permalink)
az2k Registered Member Join Date: Aug 2002 Posts: 21	A regular soup can is too short but the larger Campbells can (family size or something like that ) is OK. It is the same size as the Hunt's pasta sauce can shown at turnpoint.net I made a cantenna using the Hunt's can and it works very well. The can is on the short side based on its diameter of 3.25" but it works. Keith

09-10-2002	#9 (permalink)
Sh00t3r Registered Member Join Date: Apr 2002 Location: Michigan Posts: 199	The best results i've attained through warwalking is using my home brewed omni and then switching to the pringles can for a more directional view. Seems to work good.

09-23-2002	#11 (permalink)
astcell Stumbling Stumbler Join Date: Aug 2002 Location: Southern CA Posts: 589	Let's say you're out at the Block at Orange where there are plenty of hi rise office buildings around. Of you are in NYC. If you had a good yagi, could you conceivably point it at all the windows on the buildings, all 40 floors maybe, and get any APs that may be out there? Or do they broadcast enough so that being at the ground floor would pick them up? I'm trying to figure out the best way to stumble when hi rise office builsings are involved, surely there may be plenty of APs in those!

09-23-2002	#13 (permalink)
RaVenCorax Registered Member Join Date: Sep 2002 Posts: 4	why use a soup can or a pringles can i know some one you know does sheetmetal its not that hard to make a perfect cantenna just give em the dimensions and a few dollars stainless with mounts and predrilled holes __________________ CAW!!

09-23-2002	#14 (permalink)
astcell Stumbling Stumbler Join Date: Aug 2002 Location: Southern CA Posts: 589	I agree! THe plans I have see online for Pringles antennas are vague in the parts listing. "2 inches all-thread" is not really an item by that name, you need more info! I would love to see a difinitive parts list, just like turning your AR-15 into an M-16. Information overload baby, that's the name of the game. I wonder if offering a reward for a 50db antenna would be a challenge to anyone, and what $ amount would entice folks...

09-24-2002	#15 (permalink)
RaVenCorax Registered Member Join Date: Sep 2002 Posts: 4	sinve people are always bitchong and going on about pringles can no being metal and soup cans to short make your own or pay someone to make the perfect aize what is it 3.75 inches and 16 in long yellow pages peoples __________________ CAW!!

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