By Rick Hirsh Chrysler Corporation Tunes in with "Transistor-ized" Music Chrysler Corporation was the "first" car manufacturer, to advertise the use of transistors in its production car models. Chrysler and Philco Corporations had originally developed and produced an all- transistor car radio (Mopar model 914HR) in 1955. This “ground breaking” news was first announced in the Wall Street Journal newspaper on April 28, 1955. And it was an “option” for the new 1956 Chrysler and Imperial car models, that became available in its showrooms starting on October 21, 1955. But, it was short- lived, for Chrysler had decided to discontinue its new all-transistor car radio "option" before the end of 1956, due to poor sales and its expensive manufacturing costs to produce. Some of the advantages of using all-transistors versus tubes for car radios … Instant radio turn-on power versus 30-second warm-up time. Uses 90% less battery power supply. Produces less heat than conventional vacuum tube car radios. Uses no noisy vibrator power supply, which supplies the high-voltage needed for the radio's conventional vacuum tubes and was also the number one radio part to fail. Chrysler Corporation had decided that transistors were still the cutting edge of technology and was the wave of the future. And they had made the decision during the fall of 1956, to go with a newly developed “transistorized-hybrid” (vacuum tubes + transistors) car radio design, for all of its divisions and new 1957 car models. Large vacuum tube manufacturers like Tung-Sol had started to worry about its future, with regards to the newly developed transistor technology that would replace its vacuum tubes in car radios. And starting in late 1955, Tung-Sol had developed a special “space-charge” car radio vacuum tube, that was able to operate on a regular 12 volt car battery and it also had “eliminated ” the need for using the “noisy” troublesome car radio vibrators. These newly developed special space-charge tubes were able to replace all of the existing conventional car radio's high-voltage vacuum tubes, except for the audio output tubes, which it was not powerful enough to drive the car's speaker. Car radio and transistor manufacturers, like Philco, Motorola, Bendix, and Delco Radio were able to use these specially developed space-charge vacuum tubes into a newly developed car radio “transistorized-hybrid” design, by adding its Power Transistor to the radio's audio output circuitry. The low voltage newly developed transistorized-hybrid car radios had used 50% less battery power supply, than the older conventional vacuum tube car radios. And it also had eliminated a lot of the troublesome high-voltage car radio parts that were used, which was the vibrator power supply, power transformer, rectifier vacuum tube, and audio output vacuum tubes. Motorola had used its 2N176 or 2N178 and Philco had used its AR-6 Power Transistor, for the audio output in the 1957 Chrysler Corporation car radio's circuitry. Chrysler Corporation had complete confidence in this new transistor technology development. And they were the very “first ” car manufacturer to offer this newly developed transistorized-hybrid car radios, for all of its divisions and car models for 1957. Chrysler had called it “Transistor Powered ” and it was also much cheaper to produce, than the original (Mopar model 914HR) all-transistor car radio that was used previously for its 1956 Chrysler and Imperial car models. Chrysler Corporation had primarily used Philco and Motorola Corporations, to supply the transistorized-hybrid (Transistor Powered) car radios for its complete line of 1957 Chrysler, Imperial, Plymouth, DeSoto, and Dodge car models. Other car manufacturer's radio information ... General Motor's Delco Radio Division was the very “first” to develop and produce a transistorized- hybrid car radio (Delco model 3725156), which was an “option” for its 1956 Chevrolet Corvette car models. And General Motors had decided to offer transistorized-hybrid car radios in 1957, for its Chevrolet and Pontiac divisions only, and not for its Cadillac, Buick, or Oldsmobile division cars. Ford Motor Company had also decided to offer transistorized-hybrid car radios in 1957, but only for its Ford model cars, and not for its Lincoln/Mercury division cars. American Motors (Rambler, Nash, Hudson) did not offer transistorized-hybrid car radios in 1957. 1957 Chrysler's Transistorized-Hybrid ( Transistor Powered) Car Radios ... Chrysler Corporation had used a few different types of transistorized-hybrid (Transistor Powered) car radios for all of its divisions and 1957 car models, which was an “Electro-Touch” AM signal- seeking search tuner radio with seven push buttons, that contained six space-charge low-voltage 12v tubes and one audio output Power Transistor (Mopar models 917HR, 918HR, 919HR, 920HR, and 921HR). Another Chrysler Transistor Powered car radio model that was used was a “Music Master” AM radio with five push buttons, that contained five space-charge low-voltage 12v tubes and one audio output Power Transistor (Mopar models 845, 846, 847, 848 and 849). And one another Chrysler Transistor Powered car radio model that was used was a “Velvetone” AM radio with manual tuning only with no push buttons, that contained five space-charge low-voltage 12v tubes and one audio output Power Transistor (Mopar model 624 – Dodge car models). 1957 model - 6 vacuum tubes + 1 transistor car radio manufactured by Philco Corporation The new development of the “transistorized-hybrid ” car radio was an important “milestone,” for the car radio and electronic industries. This development was a major technology breakthrough, for it was the first time that vacuum (space-charge) tubes could operate on a regular low voltage car battery. Prior to the transistorized-hybrid car radio development, commercial car radios were originally developed in 1926 (Patent # 1,626,464) by William Heina/Automobile Radio Corporation. And it had used high- voltage vacuum tubes, which needed external high-voltage batteries to operate the car radio. And the transistorized-hybrid car radio development had also eliminated the high-voltage car radio vibrator power supply, which was originally used since 1932 and was developed by the P.R. Mallory (Elkron Division), to eliminate the use of the external high-voltage batteries that were originally needed to operate the car radio. Chrysler Corporation would continue to use the newly developed transistorized-hybrid (Transistor Powered) car radios in all of divisions and car models from 1957 until around 1963, when they finally decided started to again offer all-transistor (solid-state) car radios for their future new car models. Chrysler Corporation had made an “important milestone” starting in 1955, by opening its car doors and using the new transistor technology in its car radios. This action had “paved the road” for the future of all car radios that became fully solid-state and ending an era of using vacuum tube car radios, that first began in the late 1920's..