Transistors were introduced into domestic radios in Australia around 1958. I can actually remember the first transistor set that I owned, a pocket Sony.
By today’s standards, this set was a poor performer and was only suitable for receiving stations in the near vicinity. Its main drawback was that it generated a fair amount of noise due to the germanium transistors used.
By about 1960, Australian manufacturers were producing quite reasonable transistor radios. However, although Japanese sets were by then using PC boards (of greatly varying quality), Australian manufacturers took longer to make the transition. In fact, some Australian manufacturers didn’t use PC boards until well into the early 1960s.
As a result, some early Australian-made transistor sets were built just like valve sets, with components wired point-to-point. Some even used sockets for the transistors, just as valve sets used sockets. However, Australian manufacturers did eventually move over to PC boards – the benefits of using PC boards were simply too great to ignore, especially in terms of cost and ease of assembly.
The AWA 693P
The AWA 693P 8-transistor radio featured here is one such Australian-made set that used valve-radio construction techniques. It is a well-made 3-band receiver that was manufactured some time around 1960.
In keeping with the era, it is housed in a wooden cabinet covered with leather and leatherette. It is similar in size to the valve receivers it was intended to replace and was no lightweight either, tipping the scales at a hefty 7.2kg (ie, about the same as a valve set).
Inside, the circuit used two second-generation PNP germanium transistors for the critical RF and autodyne converter stages, while all the other stages used first-generation germanium transistors. It also used an internal telescopic antenna but there are also terminals on the rear so that an external antenna and earth can be connected for improved performance. In addition, terminals are provided to allow a portable turntable to be connected to the audio input of the receiver.
The latter feature was probably rarely used. Battery powered turntables of that era were thin on the ground and their quality left much to be desired.
Fig.1: the circuit is a conventional 8-transistor superhet design, with transistor VT1 functioning as an RF amplifier stage, VT2 as the converter, VT3 & VT4 as IF amplifiers and VT5-VT8 as the audio stages. Diode MR4 is the detector.