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| 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
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| 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,
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| 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
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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.
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