Transistor radios came in three basic sizes during the period that Australian manufacture still existed: small (little bigger than a large pack of cigarettes), medium (about the size of a house brick) and large (about the size of a medium-sized valve portable).

During this period, a lot of work was done to reduce the size of the sets while still maintaining good sensitivity and audio output. For example, in medium-sized receivers, 200mm x 12mm-diameter ferrite rods were used to ensure good sensitivity, while the batteries were kept small to keep the size and weight to a reasonable level.

Unfortunately, using small batteries also meant that they had to be replaced frequently at some cost. Many of these portables spent more time in the kitchen than outside, although they were also often used for entertainment at the beach.

Saving batteries

In order to conserve the batteries, manufacturers had to look at ways of minimising or even eliminating battery drain in some circumstances – eg, when the radio was used in the kitchen. The answer was to provide a small external power supply that would allow the set to run off the mains. A switching contact on the set’s power socket isolated the battery when the external supply was plugged in.

Although still functional, the old AWA Radiola B29 was somewhat worse for wear. It's a fairly conventional 8-transistor set from the 1960s.

The AWA B29 8-transistor radio is one such set that can be used with an external power supply (or "battery eliminator"). It was a medium-sized receiver weighing 1.6kg without a battery, or about 1.85kg with its 2364 battery fitted. By contrast, the larger AWA B32 8-transistor receiver (which has an RF stage) weighs 3.2kg without a battery and just under 4kg with its quite sizable battery fitted.

The two sets draw around the same current. However, the battery in the B32 is more than three times heavier than the B29’s 2364 battery (800g versus 250g) and it provides nearly four times the operating life.

Although hardly a lightweight at 4kg, the B32 weighed much less than the mains-powered valve portables from the 1950s and 1960s. These weighed as much as 8kg, which made them rather heavy to move around.