Fig. 287 - The era of homebrew amateur radio equipment.
In 1901, just after the famous Marconi’s successful experiment with wireless transmission spanning over the Atlantic, put on the air either the commercial and amateur radio stations. In the beguinning the first amateur radio stations consisted of “home-brew” rigs, comprising the transmitter and the receiver. The former consisted of: the spark coil, the battery power source, the telegraph key, the antenna and a good ground connection. Fig 287
Fig 288 - An early spark gap transmitter.
In order to improve the transmitted signal strenght as well as the tuning ability, soon the transmittter was incorporated with a condenser and a tapped antenna coil arranged in a closed oscillating circuit. Fig 288
The receiver accompanying the aforementioned transmitter was quite simple also. It consisted of a tuning coil, the ear phone with a by-pass capacitor, a suitable antenna switch allowing operation either for transmitting or receiving modes, and finally the radio wave detector that could be crystal, electrolitic or any type available at the time. Fig 289
Due to the limited knowledge of the radio science, the first amateur radio stations operated in a very limited radio frequency spectrum,
Fig. 289 -The receiver acomapnying the spark transmitter was very siple also as the one shown in the illustration.
generally using only long waves and maximum antenna current.
In 1907, DeForest in the USA invented the first triode valve, as known as – Audion. The Thermionics help the springing of the amateur radio hobby all over the world, giving birth to the first wireless clubs and
Fig. 290 -Hira Percy Maxim, a pioneer radio amateur. He found in 1914 the American Radio Relay League, a paradigm for the birth of similar institution all over the world.
Radio Amateur Handbook
related associations; among them “The American Radio Relay League”, in the USA, founded by the patron of radio amateurs Hiram Percy Maxim.
In Europe, an early radio-pioneer A. Steringa-Idzerda, using triode valves, named as ‘IDEEZET” built a telephonic transmitter. The valves were made from components of small incandescent lamps made in the factory founded in 1851 by Gerard and Frederich Phillips the forerunner of N.V Philips Gloeilampnfabrieken. With such transmitter, Idzerda began to broadcast concerts from Kurhaus, in Scheveningen. Fig. 290
Thus just before WWI, a radio amateur needed only a small amount of money to purchase the basic components to build himself his own radio station. The spark gaps, crystal radio wave detectors were replaced now, by the new “radio lamp”, that could actuate as a reliable detector/amplifer device of the feeble radio frequencies to enable him to have the world on his finger tips.
Therefore, the great contribuition of the knights of the ether in the direct application of the radio science was felt during the WWI from 1914-1918. During the war, the majority of radiomen in the armies’ signal corps were radio amateurs. In order to improve the war effort, their skill and knowledge was employed either for operation as well as in the manteinance of the equipments used in the early electronic warefare.