TERMS AND EXPRESSIONS

Shannon News, 25 November 1927, Page 1

TERMS AND EXPRESSIONS

The following list is taken from Harmsworth's ‘Wireless' Encyclopedia’: — Trembler. —An interrupter for induction coils resembling ?;■ the *, hammer break, but on a small scale. I .The instrument is mounted on -an l ebonite panel, and is usually attached to the end of the coil cover. Trigger Battery.—Name given, to a small battery which is inserted in the grid circuit to give the grid its initial charge when the valve is . used: ■ for transmission, Triodo.—This is another > name for the three-electrode valve. Triple Condenser .-—A triple condenser is a condenser having three" identical sets of fixed „ and a moving vanes, the latter being all on the one spindle.

T.S.F.—These are the initials of the French term ‘‘Telegraphic sans fil,” or telegraphy without wires.

T.S.H.—Those letters form the letters of the words “telegrafia- sin hilos” the Spanish term for wireless telegraphy. .

Tube. —This is an American term used largely for valves of all kinds.

Tuned Anode. —Tuned .anbde .is an expression applied to a • method of amplification characterised by the,use of an induction coil in the anode circuit of the valve.

Tuner.—The expression tuner is. applied in . radio to an apparatus comprising an i,capacity, or both, and adapted for regulating a receiving or transmitting set so that messages can be sent but or received at any desired wave length. ■ Tuning Switch. —The ‘ ‘ tuning switch” is applied to all forms of selector switch, facilitating , tuning operations in a wireless receiving ot transmitting set. » Twin-wire Aerial.— 1 of aerial employing* two wires running parallel to and insulated from, each other except at the point of contact with the lead-in wire.

Two-electrode Valve.—The twoelectrode valve has only two electrodes—the filament and the anode. The two-electrode valve was invented by J. A. Filming, and was the first step forward in wireless telegraphy.

Umbrella Aerial.—An aerial whose component wires radiate from a centre pole or mast like the ribs of an umbrella.

Valve.—Form of t rectifier or am plifier first introduced by J. A. Flem ing. It generally contains three main parts—they filament, grid, sand plate.

Variable Condenser.—The term ‘ ‘ variable condenser ” is generally applied to instruments. 4 of the . moving vane type.

Variable Grid Leak.—Term used to describe all forms of grid leak, with ready forms 'for altering their valve. Variable Inductance. —Term used to describe all forms of grid leak, which are so arranged that the effective vpJjje can be altered at will. Variable Resistance.—Strictly speak ing, all forms of adjustable resistance. Vario-eoupler.—Name given to a type of tuning device. Variometer.—A form of variable in ductance in which the variations are made without alteration to the amount of conductor.

Vernier Condenser. —A condenser of low value, used in a circuit for fint tuning purposes. y o lt.—The unit of electro /motive force. . v Watt. —Unit of electrical power. Wave Length.—The distance be tween corresponding phases of -'COnseeutive waves in a wave train'measured in the direction of propagation at any instant. Wave Trap.—A device incorporated in a radio receiving installation for eliminating local interference. Whistling.—Sound heard in the speaker of a receiving set. It is generally due to the reaction coil being too tightly coupled. Vagi Spark Gap.—Form of spark gap due . to H. Yagi.