9 PUBLIC ADDRESS SYSTEMS AND PARTS THEREOF, SOUND SYSTEMS AND PARTS THEREOF FOR PROVIDING BACKGROUND MUSIC, PAGING AND INTERCOMMUNICATION SYSTEMS BETWEEN REMOTELY SPACED LOCATIONS, ELECTRONIC ELEVATING LECTERNS AND ROSTRUMS CONSISTING OF MICROPHONES AND AMPLIFIERS AND PARTS THEREOF, PORTABLE MESSAGE ANNOUNCERS, PORTABLE DIRECTIONAL HORN SPEAKER SYSTEMS AND PARTS THEREOF, PORTABLE PUBLIC ADDRESS SYSTEMS AND MICROPHONES AND AMPLIFIERS FOR USE THEREWITH; AUDIO LEARNING DEVICES AND TEACHING AIDS - NAMELY TRANSCRIPTION PLAYERS, PHONOGRAPH RECORD PLAYERS, MAGNETIC TAPE RECORDING UNITS AND TAPE PLAYBACK UNITS, CASSSETTE RECORDER/PLAYER UNITS, COMBINATION AND RECORD-CASSETTE UNITS FOR RECORDING AND PLAYBACK, AND PARTS THEREOF; REMOTE CONTROL SYSTEMS AND COMPONENTS THEREOF - NAMELY, RADIO CONTROLLED SYSTEMS AND PARTS THEREOF FOR GARAGE AND WAREHOUSE ENTRANCE DOORS OR GATES, ANNUNCIATORS, MOTORS, BURGLAR ALARMS AND MATERIAL HANDLING APPARATUS, AND ANTENNAS, TRANSMITTERS, RECEIVERS, AND CONTROLLERS RESPONDING THERETO AND USED IN SUCH SYSTEMS; TELEVISION SERVICE AND MAINTENANCE EQUIPMENT - NAMELY, TELEVISION TUBE BRIHTENERS, TELEVISION TUBE SOCKET ADAPTERS AND VOLTAGE ADJUSTERS, ELECTRIC GARAGE DOOR OPENERS AND CLOSERS