## The Regency TR-1 was introduced on 18 October 1954 and was the worlds first commercially available domestic portable transistor radio.

Regency TR-1

In the early 1950s many people doubted the value of the new semiconductor transistors. They were expensive and not always reliable.

However many companies saw them as the future, and one of the challenges was to produce a portable transistor radio for domestic use.

The Regency TR-1 was the first portable transistor radio to be produced and it was launched on 18th October 1954. Although it cost a huge $49.95, it represented a major leap forwards. Today these Regency TR-1 radios are very rare and very collectible items, selling for many thousands of dollars each, and even then they normally do not work. ## Story behind Regency TR-1 transistor radio In the early 1950s, transistors were a novelty. They were expensive, and not always as reliable as they are today. The first transistors had all been germanium and their performance left a lot to be desired (although modern ones are far better!) Texas Instruments were a little known company at the time and they had made attracted some very talented innovators including Gordon Teal who had previously worked at Bell Laboratories. Texas Instruments needed to establish its name in the semiconductor market place. They manufactured germanium transistors, but also they introduced the first silicon transistors in 1954. A further way of establishing their name in the market was to produce a revolutionary domestic portable transistor radio, even if it used the cheaper germanium transistors of the time. Although Texas Instruments had approached several established radio companies about producing a radio using their transistors, none was interested. However one less well known company named Industrial Development Engineering Associates, I.D.E.A, which had previously focussed on building home antenna boosters, enthusiastically took up the challenge. The circuitry was developed from original Texas Instruments drawings and the cost was reduced as far as possible, because everyone knew that the price would be high. These cost reductions reduced the performance of the radio, lowering the output and reducing the specification in other areas. Even so the radio sold for$49.95 which was a huge amount in those days.

The radio was launched on 18th October 1954 and it could be obtained in a variety of colours: it was initially available in black, white, mandarin red, and light grey. Later other colours were added to the range: olive green, mahogany, and later still in lavender, pearl white, turquoise, pink, and lime.

This broke from tradition because most radios of the time were finished in wood colours or a few were available in white.

The radio measured 3 × 5 × 1.25 inches (7.62 × 12.7 × 3.2 cm) and weighed 12 ounces (340 g). This included the 22.5 volt battery that was required to power it.

## Uptake and performance

The Regency TR-1 was a major advance in technology. It was the first time that transistors had been used in a domestic radio and as a result it was well ahead of its time.

The design of the case and the overall size were also revolutionary. Such a small radio had never been seen before, and also the colours in which the radio could be obtained made a statement. In view of these aspects, the radio won a design award, and it was exhibited at the American Art and Design Exhibition in Paris in 1955.

Despite the good aesthetics, the cost cutting, which was needed to keep the price down meant that the performance was poor and it did not sell as well as had been originally anticipated.

Original prospective figures of 2.5 million units did not materialise and the radio actually sold between 100 000 and 150 000 units.

## Regency TR-1 circuit description

The TR-1 used a superheterodyne or superhet topology as the basis of the mode of operation. However the circuit was cut back to use the absolute minimum number of components as transistors were expensive, and costs needed to be minimised to ensure the radio was affordable by a sufficient number of people to make it viable.

Accordingly the circuit used only four germanium transistors and one diode.

The first transistor was used to provide the functions of local oscillator and mixer. It was similar in circuit layout to many later radios.

The second and third transistors were used as IF amplifiers which had transformer coupling between the mixer and then the two stages.

The output from the IF was applied to the detector diode which was used for both the audio output and also to provide an automatic gain control that was applied to the first IF stage.

The audio output used a single transistor. The single transistor was required to limit the number of transistors and keep the costs down, but it significantly reduced the output and the distortion levels were also high.

The Regency TR-1 was the first transistor portable radio to be made for the domestic market. It introduced new concepts of style and portability, but the performance was lacking and this significantly reduced its appeal, along with the cost!

However the TR-1 represented a significant milestone in radio receiver history and development, and it was followed by many other radios that emulated the style, and ambition of the TR-1.