Maker's Name: 
AWA (Amalgamated Wireless Australia)
Where made: 
before 1950

This item is an Australian made cathode ray oscilloscope (CRO), dating from around 1950. It has a very small display screen, a little over 5 cm in diameter. It has two amplifiers, one vertical and one horizontal, and adjustable focus and intensity controls for the electron beam. Horizontal and vertical shift controls vary the voltages on the deflection plates to shift the display on the screen. The oscilloscope has a bandwidth of 30c/s to 12 kc/s.

The cathode ray tube contains a cathode which is heated and emits electrons. These electrons are accelerated and focused into a narrow beam which passes through two pairs of parallel plates, one horizontal and one vertical. The beam is then directed onto the phosphor screen at the end of the tube where a glowing dot is formed. The dot can be moved up or down the screen by applying a voltage to the horizontal plates. When the electron beam is repetitively swept from side to side by a sawtooth ‘timebase’ voltage, the dot traces out a graph of the voltage as a function of time.

This model has been constructed completely from vacuum tube technology and predates the use of printed circuit boards. Instead, all connections are made through soldered wires, which was typical of its time. The controls of this oscilloscope do not have any calibrated scales. This means that the user can only observe qualitative information about the waveform, unless it is calibrated using an external oscillator. This item was made by Amalgamated Wireless Australia, a company which began in 1901 as a wireless agent for Telefunken, a German radio apparatus company. In 1913, following a patent enforcement lawsuit, they formed a new company, Amalgamated Wireless Australia Ltd, with exclusive rights throughout Australasia to patents ‘present and future’ of both Marconi and Telefunken. Throughout the 20th century AWA was Australia’s largest electronic organisation. They developed, manufactured and distributed valves, radios, telecommunications, televisions, audio equipment and broadcasting services.

This item is part of the UQ Physics Museum Oscilloscopes Tour
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