"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
news:ik2pg49ee82pevd4cm6atbueg5get8hjv7@4ax.com...
> On Fri, 31 Oct 2008 19:50:33 -0700 (PDT), jimmie68@gmail.com wrote:
>
>>While working on an airport S band radar I taped my WiFi detector to
>>the feedhorn and rotated the antenna. I was picking up signals from
>>all over the place, at least 100 different ones probably more that I
>>could not discern from the others. With the detector removed from the
>>feedhorn I could only get 4, I think they are all the WiFI for the
>>airport.Gain of the antenna is 31db with a cosecant squared vertical
>>radiation pattern. Its amazing what a really good antenna will do.
>>
>>Jimmie
>
> Doing the math.... well maybe not... my calculator battery just died.
> Ok, the hard way... range doubles with every 6dB of gain.
> gain = range increase over 0dBi gain
> 6dB = 2x
> 12dB = 4x
> 18dB = 8x
> 24dB = 16x
> 30dB = 32x
> So, you've picked up perhaps 32 times the range or 32^2 = 1024 times
> the coverage area with the rotating antenna. If you assume a uniform
> density of access points, you should hear 1024 times as many. Nice.
>
> The local airport (WVI/KWVI) has about 100 access point scattered
> around the hangars, neighboring businesses, flight skools, and airport
> offices. My guess is about 25% are wide open and set to the default
> settings (SSID=linksys).
>
> Um.... How did you read the wi-fi detector while the antenna was
> rotating? It must have been quite a ride.
>
> --
> Jeff Liebermann jeffl@cruzio.com
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060 http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558
>
LOL,
I can imagine him sitting astride this big rotating radar with his laptop
procariously perched on one leg.
More to the point could you imagine the pilots thoughts bringing in a 747
seeing this guy going around and around with his laptop in hand ?
OT.
A couple of weeks ago I did stick my wireless usb to an old tv arial and
managed to pick up wireless from 3 streets away. It probably helps with me
living at the top of a high rise block ........... you would be suprised how
many people have unsecured wireless available, or have named the wireless
the same as their address so its easy for them to find.
;¬)
--
Regards
Trespasser
----------------------------
I try to take one day at a time, but sometimes two or three gang up on me.
I'm not paranoid, I know your watching me. (o-o)
Show me a wireless network, I'll show you free broadband.
So you think this sigantures bad ? You should see my handwriting
----------------------------
31 db gain antenna 
Linear Mode
