SONY TR-55, THE FIRST TRANSISTOR RADIO IN JAPAN

The Grandma arrives to Sony Gallery, Barcelona

Today, The Grandma has gone to repair her TR-55 transistor radio, a valuable item that belongs to the first series that Sony, launched to the market in 1955. The Grandma has a closer relationship with transistor radios because she is from Andorra and during decades, this beautiful and small country in the middle of the Pyrenees was a meeting point, an increadible oasis for people who wanted to buy cheap technology, sugar, tobacco, alcohol and perfume in south Europe.

Before going to Sony Gallery, The Grandma has studied a new lesson of her Ms. Excel course.

Chapter 10. Spell Check (I) (Spanish Version)

 
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. Their pocket size sparked a change in popular music listening habits, allowing people to listen to music anywhere they went. Beginning in the 1980s, however, cheap AM transistor radios were superseded by devices with higher audio quality such as portable CD players, personal audio players, boomboxes, and eventually smartphones, some of which contain radios themselves.

More information: Sony

Before the transistor was invented, radios used vacuum tubes. Although portable vacuum tube radios were produced, they were typically bulky and heavy. 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. Vacuum tubes were also inefficient and fragile compared to transistors, and had a limited lifetime.

Bell Laboratories demonstrated the first transistor on December 23, 1947. The scientific team at Bell Laboratories responsible for the solid-state amplifier included William Shockley, Walter Houser Brattain, and John Bardeen. After obtaining patent protection, the company held a news conference on June 30, 1948, at which a prototype transistor radio was demonstrated.

Sony Transistor Radios

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.

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.

A workable all-transistor radio was demonstrated in August 1953 at the Düsseldorf Radio Fair by the German firm Intermetall. It was built with four of Intermetall's hand-made transistors, based upon the 1948 invention of the Transistron-germanium point-contact transistor by Herbert Mataré and Heinrich Welker. However, as with the early Texas Instruments units and others only prototypes were ever built; it was never put into commercial production.

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.

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 shock-resistant. Since the transistor base draws current, its input impedance is low in contrast to the high input impedance of the vacuum tubes. It also allowed instant-on operation, since there were no filaments to heat up.

More information: Tree Hugger

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.

By comparison, the transistor radio could fit in a pocket and weighed half a pound or less, and was powered by standard flashlight batteries or a single compact 9-volt battery. The now-familiar 9-volt battery was introduced for powering transistor radios.

Listeners sometimes held an entire transistor radio directly against the side of the head, with the speaker against the ear, to minimize the tinny sound caused by the high resonant frequency of its small speaker. Most radios included earphone jacks and came with single earphones that provided only mediocre-quality sound reproduction. To consumers familiar with the earphone-listening experience of the transistor radio, the first Sony Walkman cassette player, with a pair of high-fidelity stereo earphones, would provide a greatly contrasting display of audio fidelity.

While on a trip to the United States in 1952, Masaru Ibuka, founder of Tokyo Telecommunications Engineering Corporation, now Sony, discovered that AT&T was about to make licensing available for the transistor. 

Masaru Ibuka & his TR Models

Ibuka and his partner, physicist Akio Morita, convinced the Japanese Ministry of International Trade and Industry (MITI) to finance the $25,000 licensing fee, equivalent to $235,871 today.

For several months Ibuka traveled around the United States borrowing ideas from the American transistor manufacturers.

Improving upon the ideas, Tokyo Telecommunications Engineering Corporation made its first functional transistor radio in 1954. Within five years, Tokyo Telecommunications Engineering Corporation grew from seven employees to approximately five hundred. Other Japanese companies soon followed their entry into the American market and the grand total of electronic products exported from Japan in 1958 increased 2.5 times in comparison to 1957.

In August 1955, while still a small company, Tokyo Telecommunications Engineering Corporation introduced their TR-55 five-transistor radio under the new brand name Sony.

With this radio, Sony became the first company to manufacture the transistors and other components they used to construct the radio. The TR-55 was also the first transistor radio to utilize all miniature components. It is estimated that only 5,000 to 10,000 units were produced.

Since 1980, the popularity of portable radios has declined with the rise of portable audio players and smartphones, which allow users to carry and listen to the music of their choosing and may also include a radio tuner. This began in the late 1970s with boom boxes and portable cassette players such as the Sony Walkman, followed by portable CD players.

A common type now is the portable digital audio player. This type of device is a popular choice with listeners who are dissatisfied with terrestrial music radio because of a limited selection of music and reception problems. However, transistor radios are still popular for news, talk radio, weather, live sporting events and emergency alert applications.

More information: BT

So small it fits in your pocket. So powerful it plays everywhere.

Play it a home, at the office, when you travel... Anywhere!
 

Ad for Sony TR-610, 1958