This was a howto that I used to have on my website, it has to be at least 4 or 5 years old but I was doing some filesystem cleanup this weekend and I thought that I would post it.

The purpose of this post was to share my 802.11b homebrew wireless antenna parts list and experience. Today I have a Linksys WRT54G running the Sveasoft Talisman firmware but when I originally wrote this I was using a Linksys WAP11 access point. For a wireless card I use a Cabletron pcmcia wireless card.

The card that you use is very important important, internal wireless cards in my experience (if anyone know different please let me know) do not offer the ability to attach an external antenna. I recommend a card that uses the Prism/Prism2 chipset.

My research initially started with commercial antenna that were approx $120 to $150 for a 5dbi antenna (remember this was a few years ago and prices have come down). I then stumbled across the 802.11b Home Brew Wireless Shootout page. Since I originally wrote this I have upgraded to a commercial antenna, the thing is sick and if you never want to loose your signal I highly recommend it :). There are two important components, the antenna (in this case an omni-directional) and the amplifier.

For my homebrew antenna I choose the Flickenger coffee can waveguide design.

The hardest part of making the antenna was finding the proper parts. I have itemized the list of parts needed here:

(1) Coffe Can (36 oz, does not need to be a Yuban coffee can) – In my case it was a Maxwell House can – this happens to be what my parents drink. – $0

These parts I ordered from www.hyperlinktech.com. I would have included the direct links but they seem to change as the catalog changes.

(1) N-Female Panel Mount 4-Hole? 1 in. Flange Crimp Connector for Cable Types: RG58/141/142? Hyperlink CA195RW? WBC195? LMR195? Belden 8240/8219 – $32.90

(1) RP-TNC Plug to N-Male, 195-Series Cable – $20 (This allows connection of the antenna directly to the WAP device)

(1) ORiNOCO? AP-600/700/4000 Compatible to N-Male, 195R-Series Cable – $15 (The is for connecting the antenna directly to your pcmcia wireless card – great for war driving)

For additional instructions see Rob Flickenger’s web page on building the coffee can antenna. Happy homebrewing.
Good luck, I am in the process of doing some benchmarking on my coffee cantenna using netstumbler (http://www.netstumbler.com/). I should have the results posted after the holidays.