Ballard, William Cyrus, Jr · New York [etc.] McGraw-Hill company, inc. · leaf 18
stationary and the other is attachedto the diaphragm and free to move with it. The spacebetween the two discs is loosely packed with carbon grainsabout the size of a pin head. The carbon granules have theproperty of varying the electrical resistance between the twocarbon discs, which resistance… … diaphraoi cose
Radio
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