Amplifiers, Including Direct-Current Differential, Multichannel, Audio, Video, Audio-High-Fidelity, Stereophonic, Radio-Frequency and Broad-Band Amplifiers, Pre-Amplifiers and Power Amplifiers, and Parts Thereof, and Consoles and Housings Therefor; Radio-Wave Receiving Apparatus Including Amplitude-Modulation, Phase- and Frequency-Modulation Tuners and Parts Thereof, Single and Multi-Channel and Multiplex Circuits, Radio-Amplifying Circuits Adapted for Receiving Radio Broadcast and Television-Band Transmissions, Converters, Antennas and Transmission Lines; Radio-Wave Broadcasting, Rebroadcasting and Relay Equipment, Including Radio-Frequency Generating Apparatus and Oscillators and Parts Thereof; Recording and Reproducing Amplifier Equipment and Parts Thereof Including Phonograph Record and Magnetic Tape Recording and Reproducing Equipment; Phonograph Disc Records; Loudspeakers and Cabinets Therefor; Turntable Apparatus Including Phonograph Record Players, Pickups and Arms; Noise Suppressors; Electric Filters, Networks, Attenuators, Equalizers; and Electro-Mechanical and Electro-Acoustical Tranducers

Audio-Frequency, Video-Frequency, Carrier-Frequency, Noise and Radio-Frequency Signal Generators; Sound-Level Meters; Sound Analyzers; Meters Including Voltmeters, Ammeters, Wattmeters, and Differential Voltmeters; Electron-Beam or Cathode-Ray Devices and Indicators; Electro-Optical Indicators; Electrical Signal-Level Indicators; Sound and Radio Detecting Apparatus; and Stroboscopic Devices