Making the Radio: The Tuning Capacitor

Our capacitor was constructed from half a saucepan and a semi-circular metal plate (make sure all edges are filed smooth). The metal plate should be just a little bigger than the base of the saucepan, with a 2-3cm (about 3/4-1 inch) diameter semi-circular hole cut out from the middle of its straight edge. Screw this plate at its corners to the wooden base.

Place a piece of heavy-duty plastic sheet over the plate and tack or tape it down to keep it from slipping around.

The saucepan should be fixed above the plastic-covered metal plate by a bolt. Use washers to ensure that the spacing is as small as possible but not so tight that it can't move. Pass the bolt through the semi-circular hole in the bottom plate to avoid making electrical contact. Use the saucepan's handle to tune the radio by varying the overlap between the metal plate and the saucepan. Run a flexible wire from connector E to the saucepan, and from connector A to one of the fixing screws on the bottom plate.

The detector and earpiece 

Major funding for Rough Science was provided by the National Science Foundation. Corporate funding was provided by Subaru.

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