Noise-testing equipment
01 January 1933
The noise-testing equipment described has been specially designed to be (a) portable, (b) flexible in application, and (c) reliable. It comprises high-gain amplifiers, resonant wave analysers, variable or fixed frequency oscillators, thermo-milliam-meter sets, attenuators, search coils and a large quantity of subsidiary apparatus, such as battery boxes, resistance boxes and receivers. All connections are made by means of plug-ended cords, the cords being of the triple concentric type, the outer conductor being connected to the common earth circuit through the sleeves of the jacks. Details are given, of the various components, with a brief indication of the uses to which the equipment may be put.