From: Ellen K. 

The stuff a person can learn around here is amazing!!!!!!!

On Mon, 11 Dec 2006 20:55:51 +1200, black.hole.4.spam{at}gmail.com (Don Hills)
wrote in message :

>In article ,
>"Rich Gauszka"  wrote:
>>
>>According to the survey, the addition of Christmas and holiday ornamentation
>>(trees, decorations, etc.) to a standard office setting reduced wireless
>>signal strength by 25 percent. Furthermore, AirMagnet claims that signal
>>deterioration was increased by a factor of one-third, and made signal
>>distribution more uneven, reducing strength by an additional 10 percent in
>>different locations.
>
>I would finger the tinsel as the main offender.
>Specifically, those long "fuzzy ropes" of tinsel that are composed of
>thousands of thin metallised plastic strips, each a bit over an inch long,
>attached at one end to a string. Each strand forms a tiny radio antenna,
>"grounded" at one end. These are known as "quarter
wave" antennas because
>they absorb (and radiate) radio energy when the wavelength of the radio wave
>is 4 times their length. And you know what one quarter of a wavelength of a
>2.4 GHz wireless LAN signal is? A bit over an inch... (1.2 inches).
>
>This characteristic was employed to jam radar in World War 2 and is still
>used today. "Window", "Tinsel" or
"Chaff", as it was variously called,
>was/is composed of long thin strips of foil cut to a half wavelength of the
>radar it is intended to jam. (Half wavelength because both ends of the
>antenna are free, instead of one end being grounded.)

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