Re: Possible communications black hole.

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Crow Leader" <tesla-at-lists.symmetric-dot-net> 

These random "dead spots" are why good wireless access points have two
antennas, one may pick up a signal stronger than the other for a give
client. Look up wireless and "diversity" on google.


KEN

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, March 22, 2004 1:54 PM
Subject: Re: Possible communications black hole.


 > Original poster: Jim Lux <jimlux-at-earthlink-dot-net>
 >
 > At 08:06 AM 3/22/2004 -0700, you wrote:
 > >Original poster: "Christopher 'CajunCoiler' Mayeux" <cajuncoiler-at-cox-dot-net>
 > >I know it's likely to be something else, but is it
 > >possible that my idle Tesla coil is causing a bit
 > >of a communications "black hole" in my lab?
 > >
 > >I attempted to instigate wireless networking in
 > >the lab (802.11b-at-2.4Ghz), and found there to be a
 > >sharp drop in signal strength in a 4 foot radius
 > >around my coil. (which is not plugged in)
 > >
 > >Is this at all possible?  Or am I imagining this?
 >
 > You bet it's possible.. big metal thing, dimensions on the order of a
 > wavelength or two, all kinds of weird stuff is possible.  (2.4 GHz => 12.5
 > cm wavelength)  Of course, your body, and the antenna/laptop is also going
 > to perturb the field.
 >
 > In some (exceedingly) casual experiments over the weekend, I was mapping
 > the field strength on my kitchen table, trying to understand optimum
 > orientation and position of the laptop when sucking down that first cup of
 > coffee in the morning.  There are 10-20 dB changes in field strength over
a
 > distance of a few feet, and no apparent, obvious, pattern to it. (clearly,
 > it fits in the "complex multipath environment" category)
 >
 >
 >