The Linksys WRT54G and GS 802.11g access point is arguably one of the most customizable
on the planet. Dozens of articles and millions of happy WRT owners can attest
to this. By downloading and installing custom
firmware, you can extend the range by several hundred percent, link WRT's
into a mesh network, run it as a client, and much, much more. The guts of the
WRT54G and GS is a circuit board based on the Broadcom chipmaker reference design.
This same design can be found in similar units from ASUS, Buffalotech, Belkin,
Dell, and many more. All of these AP's have a terrific circuit board and chips
encased in cheap, mass-produced plastic and all come with the little 2.2 dBi
antennas. This is a lot like putting a Ferrari engine into the body of a Chevy
Nova. While many folks use this AP at home and are quite happy with the little
blue plastic case, a few of us want to use the WRT where it shines. Namely outside
in a wide area wireless network stretching several miles or kilometers. To do
this we need to make a few modifications.
The above image is the result of several months of experimentation. Inside is a WRT54G circuit board, 14 dBi panel antenna, Power-Over-Ethernet, and an integrated pole mount all in a waterproof case. We have run these units at max power in the worst of Swedish winters for several months with no ill effects. If they can survive a winter in Sweden with constant rain and snowfall and temperatures of -25 Celsius and the Swedish summer with temperature of 30 Celsius or more they can survive just about anywhere.
Many folks have tried various ways of shoe-horning the little blue case into weatherproof boxes. Most of these methods are going to make this unit very unhappy due to overheating, moisture collection, antenna feedback, and generally cramped quarters. We had tried these simpler methods previously and found them lacking. The result was burned out units and shortened range. Our current design solves these problems nicely.
The core of the WRT is a MIPS processor running at up to 200 MHz. This is a lot of power for such a little box and it generates a lot of heat. One of the most important requirements to meet in placing the WRT in a weatherproof box is having a way to distribute the heat. Sealing a 200 Mhz MIPS processor into an insulated box is like building a mini-WRT sauna.
So without further ado let's take a look at how to properly armor the WRT54G and GS units for outdoor use!