About the article

Spark Transmitter

-

At the end of his scientific research carried out in 1887/1888 Heinrich Hertz was able to prove the existence of electromagnetic waves and describe some of their characteristics. The experiments were not only a scientific sensation, but also enabled Guglielmo Marconi, the first ‘radio dabbler’ to set up a communications path for morse traffic. In 1896, Marconi successfully covered a distance of about 3 km using electromagnetic waves. A little later, he established radio contact across water between Lavernock Point, South Wales and Flat Holm Island. The transmitter consisted of a spark inductor coupled to a dipole antenna. At the receiver side, he used another dipole and a glass tube filled with silver and nickel filings, the so-called coherer. The filings enabled the coherer to act as a ‘defined’ bad contact with the RF pulse energy ‘rattling’ the contact and thus driving the audio amplifiers connected to the output.
The circuit shown here operates on the same principle.
Downloading of this magazine article is reserved for Elektor Members only.
Already a member? click here to log in.
Loading comments...