21 TRANSMITTING AND RECEIVING DEVICES FOR RADIO TRANSMISSION AND TELEPHONY AND PARTS THEREOF; AMPLIFIERS FOR HIGH AND LOW FREQUENCIES, ALSO AMPLIFIERS WITH ADJUSTABLE REVERBERATION EFFECT FOR EFFECTING AN ECHO SOUND; LOUDSPEAKERS AND LOUDSPEAKER COMBINATIONS; LOUDSPEAKER BOXES FOR STEREO-RECEPTION; WIRE BROADCASTING DEVICES; MICROPHONES, MICROPHONE-HOLDERS, MICROPHONE-STANDS; HEAD PHONES FOR RADIO BROADCASTING, MEASURING PURPOSES, MAGNET-TONE PURPOSES OR FOR DICTATING MACHINES; SOUND RECEIVING AND SCANNING DEVICES FOR SOUND-CARRIERS ON A MECHANICAL, MAGNETICAL,OR OPTICAL BASIS; RECORD-CUTTING DEVICES; TELEPHONE APPARATUS; NUMBER DIALS FOR TELEPHONE; INDUCTORS; RADIO AND TELEVISION SETS, ALSO TRANSISTOR PORTABLES AS WELL AS PARTS THEREOF, ALSO IN COMBINATION WITH CLOCKS, PROJECTORS FOR PROJECTION OF RADIO-RECEIVED OR STORED SIGNAL VOLTAGES, FOR INSTANCE, FOR RADIO-TELEVISION SETS; IMAGE RECTIFYING AND CLARIFYING APPARATUS; PICTURE TUBES WITH LINE SCANNED SCREEN FACE; REMOTE CONTROLS FOR PICTURE AND TONE; COMBINED MAGNET-TONE-PICTURE-PROJECTORS INCLUDING SYNCHRONIZED DRIVES; MAGNETIC-SOUND SUPPLEMENTAL DEVICES-NAMELY, MIXING DESKS FOR CONSOLIDATING VARIOUS SOUND SIGNALS AND SPEED INDICATOR FOR THE CONTROL OF THE PROJECTION OF PHOTOGRAPHS IN THE FORM OF SLIDES; FUSES; SWITCHES; AND INSULATING TAPES