Building Wireless Community Networks

The Pringles Can

At the Portland Summit last June, Andrew Clapp presented a novel yagi antenna design. It used a bolt, metal tubing, washers, and PVC tubing to make an inexpensive “shotgun” yagi, either 18” or 36” long. While his antenna shows between 12 and 15dBi gain (which is impressive for such a simple design), it’s also quite large. When we returned from Portland, some members of our local group and I realized that, if we were careful, we could fit a full wavelength inside a Pringles can, as shown in Figure 7-1. This would show a reduced total gain, but it would also make the entire antenna much more compact.

Figure 7-1. The complete antenna—it’s just a can!

Parts List

Here are the items you’ll need to make a Pringles can antenna:

Part	Approximate cost
All-thread, 5 5/8” long, 1/8” OD	$1.00
two nylon lock nuts	$0.10
five 1” washers, 1/8” ID	$0.10
6” aluminum tubing, 1/4” ID	$0.75
A connector to match your radio pigtail (we used a female N connector)	$3.00
1 1/2” piece of 12-gauge solid copper wire (we used ground wire from house electrical wiring)	negligible
A tall Pringles can (any flavor, Ridges are optional)	$1.50
Scrap plastic disc, 3” across (like another Pringles can lid)	negligible
TOTAL	$6.45

Of course, buying in bulk helps a lot. You probably won’t be able to find a 6-inch piece of all-thread; buy the standard size (usually one or two feet) and a ...