A set of cylindrical primary & secondary coils with 4mm, socket & iron core.
This coil, specially designed for school use is suitable for vacuum tubes and audiometers etc. It is wound with insulated copper wire, has tungsten contacts and on/off reversing switch as communicator. Voltage tested condensers are fitted inside the teak polish wooden box. The top of the wooden box is provided with sunmica and relevant data engraved on the sunmica. Terminals are provided for H.T. output and L.T. input of the coil. Up to 25 mm spark is obtained with 4 to 6 volt D.C. input.
Spark : 25