hello! experience with 802.11x and extreme humidity?

[Darryl Smith]

There is also some interesting information on page 154 of "802.11
Wireless Networks - The definitive guide" from O'Reilly... It includes
information on how microwave ovens actually work and the like. If you
have the book, check it out. If not, buy the book...

Darryl

---------
Darryl Smith, VK2TDS   POBox 169 Ingleburn NSW 2565 Australia
Mobile Number 0412 929 634 [+61 4 12 929 634 International] 
Darryl at radio-active.net.au | www.radio-active.net.au  

-----Original Message-----
From: wireless-admin at lists.samba.org
[mailto:wireless-admin at lists.samba.org] On Behalf Of Chris Hill
Sent: Sunday, 13 October 2002 11:10 PM
To: Armin Roehrl; wireless at lists.samba.org
Subject: RE: hello! experience with 802.11x and extreme humidity?


Hi Armin,

Why do you say that 2.4GHz is a resonance frequency of water?  It's not.

For a basic starter, see :

http://howthingswork.virginia.edu/microwave_ovens.html


The first significant atmospheric attenuation peaks that I'm aware of,
are at 22.2GHz and 183.3GHz, both caused by water vapour resonances.
Further peaks at 60GHz and 120GHz are caused by resonances of molecular
oxygen.

(See p. 696 of "Microwave Engineering", by David Pozar, ISBN
0-201-50418-9)


So, yes, a 2.4GHz signal is attenuated by atmospheric water content,
but, no, 2.4GHz is not a resonant frequency of water.

Hope this helps,



Chris

p.s  If you go to the above URL, will you be able to resist reproducing
the grape experiment? http://www.pmichaud.com/grape/







-----Original Message-----
From: wireless-admin at lists.samba.org
[mailto:wireless-admin at lists.samba.org]On Behalf Of Armin Roehrl
Sent: Saturday, 12 October 2002 10:54 PM
To: wireless at lists.samba.org
Subject: hello! experience with 802.11x and extreme humidity?


Hello all,

	I subscribed to this Australian list hoping that
s.b. here has experience how 802.11x performs
under extreme humidity (fog, rain).

2.4 GHz is a resonance frequency of water -- so
I assume the receiving quality to go down with
humidity.

What about 5.6GHz?

Does anybody have concrete numbers to share?

I think the potential temperatures would be between
18C to 35C and I expect up to 80% humidity.

Thx & thank you very much for any experience you can share.
-A.

-----------------------------------------------
Armin Roehrl, http://www.approximity.com
Training, Development and Mentoring
OOP, XP, Java, Ruby, Smalltalk, .Net, Datamining, Parallel computing,
Webservices

I can't understand why people are frightened of new ideas.
I'm frightened of the old ones.
-- John Cage