Glossary

Channel - refers to the width-modulation of the pulses by the telephone lines entering a station, providing a 'channel' for the transmission of data.

Channel Unit - the circuitry that generates the fluctuating voltage which is responsible for determining the length of a pulse width.

Gate - this is an analogous term used to describe the process of separating the pulse signals. The receiver station knows to activate a one of eight circuits along which an in-coming pulse travels. Which of these gates opens depends upon its place in sequence after the synchronisation pulse. A gate is only opened once per cycle and closes before the next signal arrives approximately 3.5µsec later thereby allowing data specific to that channel to be received by that gate.

Magnetron - device that comprises an electric circuit within a strong but variable magnetic field. Electrons are produced at the cathode and are caused to spin in the magnetic field. The effect of their spin is the creation of short-wave radiation. The magnetron is installed within a cavity, which can be set to resonate at the frequency of the radiation being produced by the electrons. The oscillator transmits this as a signal.

Oscillator - this device performs the same role during the transmission and reception phases of the set, converting and interpreting the the electrical signals which correspond to the audio-channels.

Pulser Unit - This part of the WS10 was responsible for creating the electrical pulse that is superimpose onto the radio wave produced by the magnetron.

RADAR - RAdio Direction and RAnging, has a long history in the development of radio communication and was applied most successfully by the British during the Second World War as part to their coastal defence system. Click here to learn more.

Saw-tooth voltage - this electromotive force (e.m.f) is caused by the repetitive charging and discharging of capacitors arranged in sequence within the channel unit. The magnetron valve only becomes conductive when the voltage rises above the positive bias of the cathode.

Sender Unit - At this point of the unit the electrical pulse is combined with the radio wave to produce the signal which is transmitted to the receiving station. This unit consists of the magnetron and an oscillator.

Side-lobes - this is a term that describes the edges of a radio wave. The technology of the 1940s was not sufficiently accurate to detect information transmitted here and meant radio waves were a secure for of communication. Today however, the sensitivity of radio receivers has increased to the extent that any observer of a transmission can intercept the signal being sent.

Signals Experimental Establishment (SEE) - It is under this organisation that development of the WS10 took place. The WS10 was not the only set that was developed at this site; those selected for this project often had much experience building other pieces of radio equipment for the military.

Signals Research and Development Establishment (SRDE) - This was the name subsequently given to SEE after its move to Christchurch.

SR9 - this is the government department under which SEE was initially formed and is believe to stand for 'Signals Research'. The '9' indicated how many other organisations were involved in the development of telecommunications during the war.

Synchronisation Pulse - a 20-30µsec pulse which triggers the receiving WS10 to begin opening the gates through which in-coming information is delivered to the separator unit.

Time Division Multiplexing - This is the interspersing of a signal pulse with a very small time delay so that each 'packet' of information remains distinct from others being transmitted on the same radio wave. In telecommunication, this was an efficient method of making available multiple channels down which information could 'flow'.

60ft Tower - achieved elevation of the aerials so as to extend transmission range.

Wave-guide - This device is used to extend the height at which the 4ft aerials can be positioned. It is simply a hollow cable of diameter 2" which connects to trailer to the aerial. It is along this cable that the radio wave travels during transmission and reception.