The electret microphone cartridge used in this project is about 1⁄4" in diameter. Therefore, the contact pads on the cartridge to which you solder wires are very small. Review the methods for soldering to contact pads that we  cover in Chapter 4. And don’t forget to use your magnifying glass after soldering to check for solder bridging (a clump of solder that could short out the connection) between the two pads.

If you find bridging solder, try using a utility knife to gently clean it out. Also, you might subscribe to the better-safe-than-sorry theory and consider ordering two of these microphone cartridges. That way, if you ruin one while learning how to solder to these small contact pads, you have a second one at the ready, saving you time and shipping fees for a second order. The parabolic dish comes with a reflective finish. We recommend spray painting it to avoid blinding yourself or others with the sun’s reflection from the dish’s original finish. Note: Before painting, be sure to wipe off the dish to get rid of dust or smudges because spray painting makes any smudges on the smooth surface really stand out.

Feel free to get creative when choosing a color for the dish; if you’re planning to listen to wildlife, you might want to paint the dish a color that will blend in, such as green or brown. We painted ours black because, well, we had the black paint. Use a special glue — PVC cement to connect the PVC fittings that form the microphone handle. You can get this type of glue at any building supply store. This glue provides a very strong joint, which you need because the dish is somewhat heavy and you don’t want the handle to fall apart, causing you to drop the dish on the ground. (This happened to us with a prototype we hadn’t yet glued together. Nancy’s ears are still ringing from the resulting amplified crash.) Be sure to wear some form of work gloves when using this glue because it melts plastic — you definitely don’t want this stuff on your hands! Also read the label for advice on safety, such as using the glue in a well-ventilated area as well as what to do if it does come into contact with your skin.