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What is a spark gap radio?
A spark-gap transmitter is an obsolete type of radio transmitter which generates radio waves by means of an electric spark. The radio signals produced by spark-gap transmitters are electrically “noisy”; they have a wide bandwidth, creating radio frequency interference (RFI) that can disrupt other radio transmissions.
How does spark gap radio work?
In concept, a very basic spark gap transmitter consists of a voltage source fed through a resistor to a capacitor which has the spark gap across. The voltage across the gap rises until it sparks. The spark gap is connected to the antenna which enables the signal to be radiated.
What is spark gap terminal?
A spark gap can be used to measure high voltage AC, DC, or pulses, but for very short pulses, an ultraviolet light source or radioactive source may be put on one of the terminals to provide a source of electrons.
What is the purpose of spark gap?
Spark Gaps. Gas filled spark gaps are high energy, voltage controlled switching devices, unique in their ability to repeatedly switch currents of thousands of amperes. They are ideally suited for diverting large electrical surges caused by lighting, EMP and other sources of high voltage, high current transients.
How did the spark gap transmitter get its name?
Use of the spark-gap transmitter led to many radio operators being nicknamed “Sparks” long after spark transmitters ceased to be used. Even today, the German verb “funken”, literally, “to spark”, also means “to send a radio message/signal”.
When did they start using spark gap oscillators?
As late as 1955, a Japanese radio-controlled toy bus used a spark transmitter and coherer receiver; the spark was visible behind a sheet of blue transparent plastic. Spark gap oscillators are still used to generate high frequency high voltage to initiate welding arcs in gas tungsten arc welding [1].
How did Hertz use a tuned spark gap transmitter?
Hertz used a tuned spark gap transmitter and a tuned spark gap detector (consisting of a loop of wire connected to a small spark gap) located a few meters away. In a series of UHF experiments, Hertz verified that electromagnetic waves were being produced by the transmitter.
What are the problems with the spark transmitter?
Another problem with the spark transmitter was a result of the shape of the waveform produced by each burst of electromagnetic radiation. These transmitters radiated an extremely “dirty” wide band signal which could greatly interfere with the reception of other transmissions on nearby frequencies.