>-----Original Message-----
>From: pic microcontroller discussion list [mailto:PICLIST@MITVMA.MIT.EDU]
>On Behalf Of Robert B.


>Has anybody had experiences with homebrew wifi antennas?  I built one this
>evening similar to the "cantenna" described in various places on the web,
>and it works OK, but not up to the level I was hoping for.
>
>The cantenna is located in a room separate from the desktop PC which gets
>no
>wifi signal at its manufacturer-supplied omni-antenna.  The laptop (built-
>in
>wifi) picks up a strong signal where the cantenna is located, but the
>desktop hooked to the cantenna in the same location picks up a very weak
>signal (~-85db snr).  I used about 15 feet of standard coaxial cable as the
>antenna line.. anybody know how to figure the theoretical signal loss
>through it?  I'm not sure but I doubt coax was designed for 2ghz+
>frequencies.  Does anybody know for certain?

I built one recently using a USB dongle and some Asian cookware, as
described on:

http://www.usbwifi.orcon.net.nz/

I used a free (after rebate) USB dongle from ecost.com, and a $10 18" wok
lid from "The Cupboard" (a local cookware shop - possibly a chain). I don't
have any hard performance numbers on it yet, but it can operate at much
lower SNR's than my $80 Proxim wireless card, and seems very directional.
Off the top of my head, I'd guestimate that I'm getting about 15-20db gain.
If I get around to it, I'll post a page on my website (I have pics, but no
page yet), and post it to the list.


TTYL!

- Robert

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