#TRANSISTOR RADIO WITH BLUEX PORTABLE#

#TRANSISTOR RADIO WITH BLUEX PORTABLE#

The typical portable tube radio of the fifties was about the size and weight of a lunchbox and contained several heavy, non-rechargeable batteries - one or more so-called 'A' batteries to heat the tube filaments and a large 45- to 90-volt 'B' battery to power the signal circuits. It also allowed 'instant-on' operation, since there were no filaments to heat up. Since the transistor's base element draws current, its input impedance is low in contrast to the high input impedance of the vacuum tubes.

The use of transistors instead of vacuum tubes as the amplifier elements meant that the device was much smaller, required far less power to operate than a tube radio, and was more resistant to physical shock. Sanyo 8S-P3 transistor radio, which received AM and shortwave bands. RCA had demonstrated a prototype transistor radio as early as 1952, and it is likely that they and the other radio makers were planning transistor radios of their own, but Texas Instruments and Regency Division of I.D.E.A., were the first to offer a production model starting in October 1954. However, as with the early Texas Instruments units (and others) only prototypes were ever built it was never put into commercial production. It was built with four of Intermetall's hand-made transistors, based upon the 1948 invention of the 'Transistor'-germanium point-contact transistor by Herbert Mataré and Heinrich Welker. A workable all-transistor radio was demonstrated in August 1953 at the Düsseldorf Radio Fair by the German firm Intermetall. Texas Instruments had demonstrated all-transistor AM (amplitude modulation) radios as early as May 25, 1954, but their performance was well below that of equivalent vacuum tube models. There are many claimants to the title of the first company to produce practical transistor radios, often incorrectly attributed to Sony (originally Tokyo Telecommunications Engineering Corporation). After obtaining patent protection, the company held a news conference on June 30, 1948, at which a prototype transistor radio was demonstrated. The scientific team at Bell Laboratories responsible for the solid-state amplifier included William Shockley, Walter Houser Brattain, and John Bardeen. Vacuum tubes were also inefficient and fragile compared to transistors and had a limited lifetime.īell Laboratories demonstrated the first transistor on December 23, 1947. The need for a low voltage high current source to power the filaments of the tubes and high voltage for the anode potential typically required two batteries.

Although portable vacuum tube radios were produced, they were typically bulky and heavy. Ī seven-transistor Soviet Orljonok radio with the back open, showing parts.īefore the transistor was invented, radios used vacuum tubes. Beginning around 1980, however, cheap AM transistor radios were superseded initially by the boombox and the Sony Walkman, and later on by digitally-based devices with higher audio quality such as portable CD players, personal audio players, MP3 players and (eventually) by smartphones, many of which contain FM radios. The pocket size of transistor radios sparked a change in popular music listening habits, allowing people to listen to music anywhere they went. Billions of transistor radios are estimated to have been sold worldwide between the 1950s and 2012. Transistor radios are still commonly used as car radios. The mass-market success of the smaller and cheaper Sony TR-63, released in 1957, led to the transistor radio becoming the most popular electronic communication device of the 1960s and 1970s. Following the invention of the transistor in 1947-which revolutionized the field of consumer electronics by introducing small but powerful, convenient hand-held devices-the Regency TR-1 was released in 1954 becoming the first commercial transistor radio. A classic Emerson transistor radio, circa 1958Ī transistor radio is a small portable radio receiver that uses transistor-based circuitry.

Transistor radio with bluex