Final Construction and Weatherizing

This is the final stage of the coffee can antenna project.Time to put it all together!

Step 1: Building the N-Connector

Putting this together is fairly straightforward. The radiating element should fit inside the opening of the N-Connector. This might be a snug fit, but that’s okay. If you find that the radiating element will not fit properly, sand one end of the connector using some sandpaper until the element fits.

When the fit is snug, solder the radiating element to the connector to make a permanent and electrically strong connection. Soldering even a small amount will make the difference between a great antenna and a lousy one.

Once this is done, you should have a completed Connector/Element assembly similar to the one shown in Figure 3-16.

Step 2: Mounting the N-Connector

You can now insert the completed assembly into the hole you drilled in the side of the coffee can. As we mentioned, your N-Connector might be different than the one we used. Ours had four mounting holes. Mount the connector assembly to the coffee can using the screws provided.

Make sure that the screws are just the right length or only slightly longer. If they are too long and protrude into the can more than a few millimeters, the signal will be adversely affected. Figure 3-17 shows the connector mounted to the can.

Also ensure that the wedge’s flat edge is parallel to the bottom base of the can (see Figure 3-18). This isn’t critical, but it looks better!

Step 3: Weatherizing the Antenna

Weatherizing the antenna is easy. If you plan on using the antenna outdoors, you may want to spray paint the exterior of the antenna with a rust proof paint.To protect the interior of the antenna, simply cover the opening with the original plastic cover that came with the can (you may want to glue this cover on).

Some plastics block microwave energy. To test if the lid to your can is microwave safe and will keep your antenna working great, try the following: Using a standard microwave oven, place the lid on the floor of the microwave at least 2 inches from a cup of water. Start the microwave and run it until the water starts to boil. Carefully check the lid to see if it’s hot or not. If it’s cool to the touch, microwave energy does not affect the plastic and the lid is a good covering.

The cover of an antenna that keeps weather out but does not interfere with the antenna operation or signal is called a radome. In a sense, the plastic lid on your can antenna is the radome. Neat!

Your can antenna is now done! Now put the antenna to use by attaching it to the cable and pigtail you built in Chapter 1 (see Figure 3-19).