PREOSTAT

[ RADIO RECEIVERS AND PARTS THEREOF; LOUDSPEAKERS, SWITCHES, FIXED AND ] CONTROLLABLE COATED AND WIRE-WOUND RESISTORS, ROTARY RESISTORS, AND VOLTAGE DIVIDERS HAVING A SWITCH ATTACHED THERETO, ROTARY RESISTORS AND VOLTAGE DIVIDERS FOR USE AS VOLUME AND TONE CONTROLLERS, AND GANGED ROTARY RESISTORS AND VOLTAGE DIVIDERS