Cheap Stereo Microphone
Made from Radio Shack Stereo Clip-On Microphone(33-3028)
Perky-Pet Squirrel Baffler (No. 340)
The microphones are separated from each other with the cut off cap of a ballpoint pen. I have started with a separation distance of 1.75 inches as my first trial. The iron wire is threaded through the cap. This will mount the microphones to the parabola. A rubber band is threaded through the cap to hold the two microphones.
I have been using the threaded rods and rubber bands as a mounting method for many years and it has allow me to adjust the microphone distance for best results.
The parabola was reshaped from the squirrel baffle by baking it in a oven at 300 degrees F. for 15 minutes and squashing it between a plaster of paris die and mold I made. It has held its shape for four years without relaxing to its original shape. As you can see the mount is well worn, and I haven't lost a microphone yet. (Who would care they are cheap!)
The parabola is only 16 inches in diameter( I do have an 18 inch and 54 inch) but since I am usually hunting warblers it doesn't seem to make a difference.
By the way the 54 inch is made from cardboard to an old Scientific American recipe.