Sony

Sony Gendis TR72

The transistor had been invented by Bardeen, Brattain and Shockley of Bell Laboritories in 1948, but what to do with it?

Akio Morita, in his autobiagraphy 'Made in Japan': Akio Marita and Sony writes about how he visitited Bell labs and gleened as much information about the makeup of transisitors as posible. His company simply didn't have the money to licence the transistor. His engineers set forth to make a transisitor and improve upon it. Morita beleived in the transistor as a way forward for the fledgling company from their failures such as a rice cooker that used the moisture to switch off the machine once the rice was cooked, and a sort of electric blanket that caught fire! They were having some success with a valve reel to reel tape recorder though.

Regency in the USA also had the idea of making a transistor radio and licenced the technology from Bell Lab's and managed to release their radio some six months prior to Tokyo Tsushin Kogyo company of Japan or Sony as it was to become known.

Although Sony was beaten at the post, in mid 1955 they released the TR55. This was the successor to the TR53. However, the TR53 had issues with the cabinet that had poor glue, thus allowing the front grill to fall off. It also had plastic cabinet that deformed in the right (wrong) conditions. This delay allowed Sony to improve the design of the TR55 and to fix production problems.

Unlike the Regency that used a 22.5 volt battery, the TR 55 used 4 1.5 volt cells for 6 volts setting the scene for low voltage radios. It was also small at 140 x 89 x 38 mm.

The TR55 was released in August 1955, around the same time as the Raython 8TP and models by General Electric.

Gendis is a Canadian company that was setup by Albert Cohen and his five brothers in the late 1940. They ran a chain of electrical stores and a large distribution network. Sony was looking for an "in" into the North American market.  It's not clear who approached who, but a parnership was agreed. Gendis had a self branded radio, and Sony had a Canadian partner.

Born from the parnership came the TR72.

The TR72 is a table model measuring 260 x 178 x 83 mm. It runs on on 3 1.5 volt cells for 4.5 volts and has 7 germainium transistors, and a number of germainium diodes.  Surprisingly, it is completely orginal and works.

Sony made around 40,000 of the sets over 3 years. A huge amount for a new technology and a company that was little more than 10 years old. My example is one of the later builds, and is Serial Number 34,893.  It works beautifully.  

It will be featured in a coming issue of Silicon Chip magazine in Australia and New Zealand, where Ian Batty will detail the workings of the radio.