Spark-gap transmitter

The bang radio transmitter was used to transmit messages in the form of Morse code wireless. The principle is based on the experimental evidence of the predicted by James Clerk Maxwell electromagnetic waves by Heinrich Hertz in 1886.

Operation

The capacitor C1 is charged to a high voltage ( depending on the plant some kV up to 100 kV). Once ignited, the spark gap, the two capacitors are connected in parallel, and a very large charging current flows to the capacitor C2, which forms a resonant circuit with a coil. The resonant circuit is the energy transmitted from the antenna that emits an evanescent wave. Thus, the resulting spark goes out again, which subsequently flowing current must be limited by a resistor. Upon discharge, a loud bang, like thunder in a thunderstorm.

Disadvantages

In the 1920s, pop radio stations were banned because they disturbed by the large bandwidth of the signal generated the reception of other stations. Once ignited, the spark gap, the frequency is lowered due to the parallel connection of the two capacitors C1 and C2. After extinction of the spark gap, the transmission rate increases because only C2 is connected to the coil. Another reason for the wide range is that generate sparks in principle with respect to the sinusoidal form a strongly distorted and thus broadband signal. This can be easily observed in the roaring noise of thunder flashes on the radio on long, medium and short wave. In addition, in this transmission technique, the resonant circuit only a short time is triggered, which affects the turn, and thus the effect of the circle. Also a lot of energy passes through the transfer of the charge on C2 is lost, which reduces the transmission power. The pop radio station in 1906 evolved into the quenched spark transmitter.

History

The Italian radio pioneer Guglielmo Marconi turned on with this type of station records. In 1899 he managed to overcome the English Channel, and in 1901 he presented a radio link across the North Atlantic by pop radio transmitter ago. In 1909, Marconi received and Ferdinand Braun, the basic technical requirements for the performance of the transmitter Marconi created, "in recognition of their contributions to the development of wireless telegraphy " the Nobel Prize for physics.

The flow of information called " spark telegraphy ", abbreviated FT. The German company Telefunken headed it from 1903 her name. First and most important supporter of the new technology was the particular military. There was also great interest in seafaring; 1909, the first FT distress call was transmitted.