How to Make Parabolic Listening Devices
- 1). Cut the horn off of a small satellite dish using a hacksaw or other cutting tool. The horn is a small detector suspended above the surface of the reflector by a pole.
- 2). Position a vocal microphone so that its screen is right at the spot where the horn used to be. You may have to cut off part of the pole to get the mic positioned right. Attach the mic to the rod with epoxy to hold it in position.
- 3). Tape a small headphone amplifier to the back of the listening device. Tape the microphone's cord to the rod holding it in front of the dish, and plug the end of the cord into the headphone amp.
- 4). Plug in headphones and switch on the amp. Point the parabolic listening device at whatever you want to hear.
Source...