Tin Cantenna Made With Compact / Dongle USB Wireless Adapter

 for Long Distance Wireless Reception

 

July 7, 2004

 

 

Earlier this summer I installed DSL high speed internet and a Wireless Access Point at the marina where I keep my boat.  We chose DSL due to its significantly lower cost than cable internet.  For the Access point I installed a Linksys WRT54G.  I added a +11dBi external antenna from Fab-Corp (www.fab-corp.com).  We now have 802.11b and 802.11g wireless reception throughout the marina.

 

Next was to provide wireless access from my condo across the parking lot from the marina main clubhouse where the wireless access point and antenna is located.

 

I tried various USB adapters with only marginal success.  I would get a stable connection only intermittently.

 

I also tried a brand new Linksys WRE54g Range Extender.  No improvement.

 

Finally, after researching extending the range of wireless internet networks, using Google searches, I read about cantennas.  I had read about them previously.  The originated as a “Pringles can” with a small piece of wire as antenna and connected back to a wireless card with an external antenna connection.  However, in this search I learned about people using USB wireless devices in the cans.  No soldering or special fittings is required.  Now this IS something that even I can do!

 

I found a great web site with information on selecting the can diameter and length.  It also includes calculations for exactly where to place the hole in the side of the can to position the antenna the correct distance from the bottom of the can.

http://www.turnpoint.net/wireless/cantennahowto.html

 

I then purchased a D-link DWL-122 802.11b USB wireless adapter.  It is about 1 x 3 inches and rather flat.  On the end is a USB plug.  Also included was an approx 5 foot USB extension cord.

 

I used the web site to do the calculations and found that an empty and already cleaned out 1 lb. coffee can I had was close to perfect.  I drilled one large hold at the correct spot and used pliers to enlarge it to allow the USB plug to pass through.  I inserted the device in the can and connected it through the hold to the extension cord. 

 

Since my PC is next to a window with a clear view of the marina building (but not the antenna which is above the 2nd story on the opposite side of the building – with two sides of sloping roof between me and the antenna), I ran the extension cord out the window and taped the can to a plastic chair on the porch.  Aimed at the proper place.

 

Lastly I replaced the plastic lid on the can.

 

My Windows XP Pro PC reports the connection status as:

            Speed:  11 Mbps

            Signal Strength:  2 green bars (out of 5 possible)

 

I did Verizon speed tests on the link.  Results were generally around 1200 kbps down / 150k up.  Not sure why the up is lower except probably the lower signal strength from my USB adapter vs. the received signal strength.

 

If you have questions, contact the author at:

 

Bobalston9    AT    yahoo    DOT   com

 

 

Bob Alston

 

 

Keywords:

 

Tin can  -  can antenna  - tin cantenna

Compact USB wireless adapter 802.11b  802.11g

Extend internet wireless range / distance