31 db gain antenna

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

Reply to
jimmie68
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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.

Reply to
Jeff Liebermann

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.

;¬)

Reply to
Trespasser

We were doing maint on the antenna. It was shut down at the time.

Jimmie

Reply to
jimmie68

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