The dawn of amateur radio in the U.K.(收音机雏形的诞生)

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The dawn of amateur radio in the U.K. and Greece : a personal view

The dawn of amateur

radio in the U.K.

Norman F. Joly.

The dawn of amateur radio in the U.K. and Greece : a personal view

Prologue

Thales of Miletus.

Thales, who was born in 640 B.C., was a man of exceptional wisdom

and one of the Seven Sages of Ancient Greece. He was the father of Greek,

and consequently of European philosophy and science. His speculations

embraced a wide range of subjects relating to political as well as to

celestial matters. One must remember that even up to the 18th century

there was no clear distinction between philosophy and science, both being

products of the human mind in its attempts to explain reality.

Thales had studied astronomy in Egypt so he was able to draw up

accurate tables forecasting when the River Nile would be in flood. But he

first became widely known by anticipating an eclipse of the sun for May

585 B.C., which happened to coincide with the final battle of the war

between the Lydians and the Persians. He had used some tables drawn up

by Babylonian astronomers, but he did not succeed in forecasting the exact

day (May 28th) or the hour of the spectacular event.

It can well be said that Thales was the first man ever recorded to have

cornered the market in a commodity: having foreseen a three-year drought

he bought up large quantities of olive oil and stored it for sale at a later

date.

But who could possibly have imagined that one of Thales' original

speculations would affect the Radio Amateurs of the 20th Century? He

believed that certain inanimate substances, like lodestones (magnetic rocks)

and the resin amber, possessed psyche (a soul).

Many centuries had to elapse before this soul was identified as static

electricity and magnetism and harnessed for the generation of mains

electricity which dramatically altered the pattern of life on our planet - and

also led to the creation of our hobby of Amateur Radio.

About 400 years ago an English scientist called William Gilbert

(1544-1603), who had read about the unexplained observation of Thales,

also became interested in the intangible property and decided to call it

electricity, from the classical Greek word for amber, which is electron.

The dawn of amateur radio in the U.K. and Greece : a personal view

CHAPTER ONE

THE DEVELOPMENT OF ELECTRICITY

The phenomenon which Thales had observed and recorded five

centuries before the birth of Christ aroused the interest of many scientists

through the ages. They made various practical experiments in their efforts

to identify the elusive force which Thales had likened to a 'soul' and which

we now know to have been static electricity.

Of all forms of energy, electricity is the most baffling and difficult to

describe. An electric current cannot be seen. In fact it does not exist

outside the wires and other conductors which carry it. A live wire carrying

a current looks exactly the same and weighs exactly the same as it does

when it is not carrying a current. An electric current is simply a movement

or flow of electrons.

Benjamin Franklin, the American statesman and scientist born in

Boston in 1706, investigated the nature of thunder and lightning by flying

a child's kite during a thunderstorm. He had attached a metal spike to the

kite, and at the other end of the string to which the kite was tied he secured

a key. As the rain soaked into the string, electricity flowed freely down the

string and Franklin was able to draw large sparks from the key. Of course

this could have been very dangerous, but he had foreseen it and had

supported the string through an insulator. He observed that this electricity

had the same properties as the static electricity produced by friction.

But long before Franklin many other scientists had carried out

research into the nature of electricity.

In England William Gilbert (1544-1603) had noticed that the powers

of attraction and repulsion of two non-metallic rods which he had rubbed

briskly were similar to those of lodestone and amber - they had acquired

the curious quality we call magnetism. Remembering Thales of old he

coined the word 'electricity'.

Otto von Guericke (1602-1686) a Mayor of Magdeburg in Germany,

was an amateur scientist who had constructed all manner of gadgets. One

of them was a machine consisting of two glass discs revolving in opposite

directions which produced high voltage charges through friction. Ramsden

The dawn of amateur radio in the U.K. and Greece : a personal view

and Wimshurst built improved versions of the machine.

A significant breakthrough occurred when Alessandro Volta (1745-

1827) in Italy constructed a simple electric cell (in 1799) which produced

a flow of electrons by chemical means. Two plates, one of copper and the

other of zinc, were placed in an acid solution and a current flowed through

an external wire connecting the two plates. Later he connected cells in

series (voltaic pile) which consisted of alternate layers of zinc and copper

discs separated by flannel discs soaked in brine or acid which produced a

higher electric pressure (voltage). But Volta never found the right

explanation of why his cell was working. He thought the flow of electric

current was due to the contact between the two metals, whereas in fact it

results from the chemical action of the electrolyte on the zinc plate.

However, his discovery proved to be of incalculable value in research, as

it enabled scientists to carry out experiments which led to the discoveries

of the heating, lighting, chemical and magnetic effects of electricity.

One of the many scientists and physicists who took advantage of the

'current electricity' made possible by Volta's cells was Hans Christian

Oersted (1777-1851) of Denmark. Like many others he was looking for a

connection between the age-old study of magnetism and electricity, but

now he was able to pass electric currents through wires and place magnets

in various positions near the wires. His epoch-making discovery which

established for the first time the relationship between magnetism and

electricity was in fact an accident.

While lecturing to students he showed them that the current flowing

in a wire held over a magnetic compass needle and at right angles to it

(that is east-west) had no effect on the needle. Oersted suggested to his

assistant that he might try holding the wire parallel to the length of the

needle (north-south) and hey presto, the needle was deflected! He had

stumbled upon the electromagnetic effect in the first recorded instance of a

wire behaving like a magnet when a current is passed through it.

A development of Oersted's demonstration with the compass needle

was used to construct the world's first system of signaling by the use of

electricity.

In 1837 Charles Wheatstone and William Cooke took out a patent for

The dawn of amateur radio in the U.K. and Greece : a personal view

the world's first Five-needle Telegraph, which was installed between

Paddington railway station in west London and West Drayton station a few

miles away. The five copper wires required for this system were embedded

in blocks of wood.

Electrolysis, the chemical decomposition of a substance into its

constituent elements by the action of an electric current, was discovered

by the English chemists Carlisle and William Nicholson (1753-1815). If

an electric current is passed through water it is broken down into the two

elements of which it is composed -- hydrogen and oxygen. The process is

used extensively in modern industry for electroplating. Michael Faraday

(1791-1867) who was employed as a chemist at the Royal Institution, was

responsible for introducing many of the technical terms connected with

electrolysis, like electrolyte for the liquid through which the electric

current is passed, and anode and cathode for the positive and negative

electrodes respectively. He also established the laws of the process itself.

But most people remember his name in connection with his practical

demonstration of electromagnetic induction.

In France Andre-Marie Ampere (1775-1836) carried out a complete

mathematical study of the laws which govern the interaction between

wires carrying electric currents.

In Germany in 1826 a Bavarian schoolmaster Georg Ohm (1789-

1854) had defined the relationship between electric pressure (voltage),

current (flow rate) and resistance in a circuit (Ohm's law) but 16 years had

to elapse before he received recognition for his work.

Scientists were now convinced that since the flow of an electric

current in a wire or a coil of wire caused it to acquire magnetic properties,

the opposite might also prove to be true: a magnet could possibly be used

to generate a flow of electricity.

Michael Faraday had worked on this problem for ten years when

finally, in 1830, he gave his famous lecture in which he demonstrated, for

the first time in history, the principle of electromagnetic induction. He had

constructed powerful electromagnets consisting of coils of wire. When he

caused the magnetic lines of force surrounding one coil to rise and fall by

interrupting or varying the flow of current, a similar current was induced

The dawn of amateur radio in the U.K. and Greece : a personal view

in a neighbouring coil closely coupled to the first.

The colossal importance of Faraday's discovery was that it paved the

way for the generation of electricity by mechanical means. However, as

can be seen from the drawing, the basic generator produces an alternating

flow of current.(A.C.)

Rotating a coil of wire steadily through a complete revolution in the

steady magnetic field between the north and south poles of a magnet

results in an electromotive force (E.M.F.) at its terminals which rises in

value, falls back to zero, reverses in a negative direction, reaches a peak

and again returns to zero. This completes one cycle or sine wave. (1Hz in

S.I.units).

In recent years other methods have been developed for generating

electrical power in relatively small quantities for special applications.

Semiconductors, which combine heat insulation with good electrical

conduction, are used for thermoelectric generators to power isolated

weather stations, artificial satellites, undersea cables and marker buoys.

Specially developed diode valves are used as thermionic generators with

an efficiency, at present, of only 20% but the heat taken away from the

anode is used to raise steam for conventional power generation.

Sir Humphry Davy (1778-1829) one of Britain's leading chemists of

the 18th century, is best remembered for his safety lamp for miners which

cut down the risk of methane gas explosions in mines. It was Davy who

first demonstrated that electricity could be used to produce light. He

connected two carbon rods to a heavy duty storage battery. When he

touched the tips of the rods together a very bright white light was

produced. As he drew the rods apart, the arc light persisted until the tips

had burnt away to the critical gap which extinguished the light. As a

researcher and lecturer at the Royal Institution Davy worked closely with

Michael Faraday who first joined the institution as his manservant and

later became his secretary. Davy's crowning honour in the scientific world

came in 1820, when he was elected President of the Royal Society.

In the U.S.A. the prolific inventor Thomas Alva Edison (1847-1831)

who had invented the incandescent carbon filament bulb, built a number of

electricity generators in the vicinity of the Niagara Falls. These used the

The dawn of amateur radio in the U.K. and Greece : a personal view

power of the falling water to drive hydraulic turbines which were coupled

to the dynamos. These generators were fitted with a spinning switch or

commutator (one of the neatest gadgets Edison ever invented) to make the

current flow in unidirectional pulses (D.C.) In 1876 all electrical

equipment was powered by direct current.

Today mains electricity plays a vital part in our everyday lives and its

applications are widespread and staggering in their immensity. But we

must not forget that popular demand for this convenient form of power

arose only about 100 years ago, mainly for illumination.

Recent experiments in superconductivity, using ceramic instead metal

conductors have given us an exciting glimpse into what might be achieved

for improving efficiency in the distribution of electric power.

Historians of the future may well characterise the 20th century as `the

century of electricity & electronics'. But Edison's D.C. generators could

not in themselves, have achieved the spectacular progress that has been

made. All over the world we depend totally on a system of transmitting

mains electricity over long distances which was originally created by an

amazing inventor whose scientific discoveries changed, and are still

changing, the whole world. His name was scarcely known to the general

public, especially in Europe, where he was born.

Who was this unknown pioneer? Some people reckon that it was this

astonishing visionary who invented wireless, remote control, robotics and

a form of X-ray photography using high frequency radio waves. A patent

which he took out in the U.S.A. in 1890 ultimately led to the design of the

humble ignition coil which energises billions and billions of spark plugs in

all the motor cars of the world. His American patents fill a book two

inches thick. His name was Nicola Tesla (1856-1943).

Nicola Tesla was born in a small village in Croatia which at that time

formed part of the great Austro-Hungarian Empire. Today it is a northern

province of Yugoslavia, a state created after the 1914-1918 war. Tesla

studied at the Graz Technical University and later in Budapest. Early in his

studies he had the idea that a way had to be found to run electric motors

directly from A.C. generators. His professor in Graz had assured him

categorically that this was not possible. But young Tesla was not

The dawn of amateur radio in the U.K. and Greece : a personal view

convinced. When he went to Budapest he got a job in the Central

Telegraph Office, and one evening in 1882, as he was sitting on a bench in

the City Park he had an inspiration which ultimately led to the solution of

the problem.

Tesla remembered a poem by the German poet Goethe about the sun

which supports life on the earth and when the day is over moves on to give

life to the other side of the globe. He picked up a twig and began to

scratch a drawing on the soil in front of him. He drew four coils arranged

symmetrically round the circumference of a circle. In the centre he drew a

rotor or armature. As each coil in turn was energised it attracted the rotor

towards it and the rotary motion was established. When he constructed the

first practical models he used eight, sixteen and even more coils. The

simple drawing on the ground led to the design of the first induction motor

driven directly by A.C.electricity.

Tesla emigrated to the U.S.A. in 1884. During the first year he filed

no less than 30 patents mostly in relation to the generation and distribution

of A.C. mains electricity. He designed and built his `A.C. Polyphase

System' which generated three-phase alternating current at 25 Hz. One

particular unit delivered 422 amperes at 12,000 volts. The beauty of this

system was that the voltage could be stepped down using transformers for

local use, or stepped up to many thousands of volts for transmission over

long distances through relatively thin conductors. Edison's generating

stations were incapable of any such thing.

Tesla signed a lucrative contract with the famous railway engineer

George Westinghouse, the inventor of the Westinghouse Air Brake which

is used by most railways all over the world to the present day. Their

generating station was put into service in 1895 and was called the Niagara

Falls Electricity Generating Company. It supplied power for the

Westinghouse network of trains and also for an industrial complex in

Buffalo, New York.

After ten years Tesla began to experiment with high frequencies. The

Tesla Coil which he had patented in 1890 was capable of raising voltages

to unheard of levels such as 300,000 volts. Edison, who was still

generating D.C., claimed A.C. was dangerous and to prove it contracted

The dawn of amateur radio in the U.K. and Greece : a personal view

with the government to produce the first electric chair using A.C. for the

execution of murderers condemned to death. When it was first used it was

a ghastly flop. The condemned man moaned and groaned and foamed at

the mouth. After four minutes of repeated application of the A.C.voltage

smoke began to come out of his back. It was obvious that the victim had

suffered a horribly drawn-out death.

Tesla said he could prove that A.C. was not dangerous. He gave a

demonstration of high voltage electricity flowing harmlessly over his body.

But in reality, he cheated, because he had used a frequency of 10,000

cycles (10 kHz) at extremely low current and because of the skin effect

suffered no harm.

One of Tesla's patents related to a system of lighting using glass tubes

filled with fluorine (not neon) excited by H.F.voltages. His workshop was

lit by this method. Several years before Wilhelm Roentgen demonstrated

his system of X-rays Tesla had been taking photographs of the bones in his

hand and his foot from up to 40 feet away using H.F.currents.

More astonishing still is the fact that in 1893, two years before

Marconi demonstrated his system of wireless signaling, Tesla had built a

model boat in which he combined power to drive it with radio control and

robotics. He put the small boat in a lake in Madison Square Gardens in

New York. Standing on the shore with a control box, he invited onlookers

to suggest movements. He was able to make the boat go forwards and

backwards and round in circles. We all know how model cars and aircraft

are controlled by radio today, but when Tesla did it a century ago the

motor car had not been invented, and the only method by which man could

cover long distances was on horseback!

Many people believe that a modification of Tesla's `Magnifying

Transmitter' was used by the Soviet Union when suddenly one day in

October 1976 they produced an amazing noise which blotted out all radio

transmissions between 6 and 20 MHz. (The Woodpecker) The B.B.C., the

N.B.C. and most broadcasting and telecommunication organisations of the

world complained to Moscow (the noise had persisted continuously for 10

hours on the first day), but all the Russians would say in reply was that

they were carrying out an experiment. At first nobody seemed to know

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The dawn of amateur radio in the U.K.(收音机雏形的诞生)

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