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.Perusing the Parts List ................................................................................
Here comes our favorite part — shopping for parts! The upcoming Figures 6-3
and 6-4 show many of the parts used in this project.Here’s what you’ll need:Electret microphone cartridgeTrust us. We tried a lot of microphones to get this working just right
(and save you the trouble). We finally decided on the Panasonic part
#WM61A because of its very high sensitivity that allows it to pick up
faint sounds. We found the WM61 at Digikey (www.digikey.com).
10 kohm potentiometer (R2)10 ohm resistor (R3)
5.6 kohm resistor (R1)0.1 microfarad ceramic capacitor (C1)
0.047 microfarad ceramic capacitor (C5)10 microfarad electrolytic capacitors (C2, C3)Chapter 6: Focusing Sound with a Parabolic Microphone 119