INSPECTION, MAINTENANCE AND RECHARGING FIRE. EXTINGUISHERS. The provisions of this bulletin apply to the selection, installation, inspection, maintenance and testing of portable extinguishing equipment. This guide is prepared for. the use of persons charged with selecting, purchasing, installing, and maintaining. portable fire extinguishers. The following requirements are excerpts from the National.
On 27 August 1920, regular wireless broadcasts for entertainment began in Argentina, pioneered by the group around Enrique Telemaco TelÃ©maco, susini and spark gap telegraphy. Stopped on 31 august 1920 the first known radio news program was broadcast by STATION, 8mk the unlicensed predecessor OF (WWJ) am In, Detroit. michigan
A transistor radio is a small portable radio receiver that uses transistor-based circuitry. Following their development in 1954, made possible by the invention of the transistor in 1947, they became the most popular electronic communication device in history, with billions manufactured during the 1960s and 1970s.