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THE RADIO AMATEUR'S HAND BOOK

[Illustration: A. Frederick Collins, Inventor of the Wireless
Telephone, 1899. Awarded Gold Medal for same, Alaska Yukon Pacific
Exposition, 1909.]




THE RADIO AMATEUR'S HAND BOOK

A Complete, Authentic and Informative Work on Wireless Telegraphy and
Telephony

BY

A. FREDERICK COLLINS

Inventor of the Wireless Telephone 1899; Historian of Wireless
1901-1910; Author of "Wireless Telegraphy" 1905





TO

WILLIAM MARCONI

INVENTOR OF THE WIRELESS TELEGRAPH




INTRODUCTION


Before delving into the mysteries of receiving and sending messages
without wires, a word as to the history of the art and its present day
applications may be of service. While popular interest in the subject
has gone forward by leaps and bounds within the last two or three
years, it has been a matter of scientific experiment for more than a
quarter of a century.

The wireless telegraph was invented by William Marconi, at Bologna,
Italy, in 1896, and in his first experiments he sent dot and dash
signals to a distance of 200 or 300 feet. The wireless telephone was
invented by the author of this book at Narberth, Penn., in 1899, and
in his first experiments the human voice was transmitted to a distance
of three blocks.

The first vital experiments that led up to the invention of the
wireless telegraph were made by Heinrich Hertz, of Germany, in 1888
when he showed that the spark of an induction coil set up electric
oscillations in an open circuit, and that the energy of these waves
was, in turn, sent out in the form of electric waves. He also showed
how they could be received at a distance by means of a ring detector,
which he called a _resonator_

In 1890, Edward Branly, of France, showed that metal filings in a tube
cohered when electric waves acted on them, and this device he termed a
_radio conductor_; this was improved upon by Sir Oliver Lodge, who
called it a coherer. In 1895, Alexander Popoff, of Russia, constructed
a receiving set for the study of atmospheric electricity, and this
arrangement was the earliest on record of the use of a detector
connected with an aerial and the earth.

Marconi was the first to connect an aerial to one side of a spark gap
and a ground to the other side of it. He used an induction coil to
energize the spark gap, and a telegraph key in the primary circuit to
break up the current into signals. Adding a Morse register, which
printed the dot and dash messages on a tape, to the Popoff receptor he
produced the first system for sending and receiving wireless telegraph
messages.

[Illustration: Collins' Wireless Telephone Exhibited at the Madison
Square Garden, October 1908.]

After Marconi had shown the world how to telegraph without connecting
wires it would seem, on first thought, to be an easy matter to
telephone without wires, but not so, for the electric spark sets up
damped and periodic oscillations and these cannot be used for
transmitting speech. Instead, the oscillations must be of constant
amplitude and continuous. That a direct current arc light transforms a
part of its energy into electric oscillations was shown by Firth and
Rogers, of England, in 1893.

The author was the first to connect an arc lamp with an aerial and a
ground, and to use a microphone transmitter to modulate the sustained
oscillations so set up. The receiving apparatus consisted of a
variable contact, known as a _pill-box_ detector, which Sir Oliver
Lodge had devised, and to this was connected an Ericsson telephone
receiver, then the most sensitive made. A later improvement for
setting up sustained oscillations was the author's _rotating
oscillation arc_.

Since those memorable days of more than two decades ago, wonderful
advances have been made in both of these methods of transmitting
intelligence, and the end is as yet nowhere in sight. Twelve or
fifteen years ago the boys began to get fun out of listening-in to
what the ship and shore stations were sending and, further, they began
to do a little sending on their own account. These youngsters, who
caused the professional operators many a pang, were the first wireless
amateurs, and among them experts were developed who are foremost in
the practice of the art today.

Away back there, the spark coil and the arc lamp were the only known
means for setting up oscillations at the sending end, while the
electrolytic and crystal detectors were the only available means for
the amateur to receive them. As it was next to impossible for a boy to
get a current having a high enough voltage for operating an
oscillation arc lamp, wireless telephony was out of the question for
him, so he had to stick to the spark coil transmitter which needed
only a battery current to energize it, and this, of course, limited
him to sending Morse signals. As the electrolytic detector was
cumbersome and required a liquid, the crystal detector which came into
being shortly after was just as sensitive and soon displaced the
former, even as this had displaced the coherer.

A few years ahead of these amateurs, that is to say in 1905, J. A.
Fleming, of England, invented the vacuum tube detector, but ten more
years elapsed before it was perfected to a point where it could
compete with the crystal detector. Then its use became general and
workers everywhere sought to, and did improve it. Further, they found
that the vacuum tube would not only act as a detector, but that if
energized by a direct current of high voltage it would set up
sustained oscillations like the arc lamp, and the value of sustained
oscillations for wireless telegraphy as well as wireless telephony had
already been discovered.

The fact that the vacuum tube oscillator requires no adjustment of its
elements, that its initial cost is much less than the oscillation arc,
besides other considerations, is the reason that it popularized
wireless telephony; and because continuous waves have many advantages
over periodic oscillations is the reason the vacuum tube oscillator is
replacing the spark coil as a wireless telegraph transmitter.
Moreover, by using a number of large tubes in parallel, powerful
oscillations can be set up and, hence, the waves sent out are radiated
to enormous distances.

While oscillator tubes were being experimented with in the research
laboratories of the General Electric, the Westinghouse, the Radio
Corporation of America, and other big companies, all the youthful
amateurs in the country had learned that by using a vacuum tube as a
detector they could easily get messages 500 miles away. The use of
these tubes as amplifiers also made it possible to employ a loud
speaker, so that a room, a hall, or an out-of-door audience could hear
clearly and distinctly everything that was being sent out.

The boy amateur had only to let father or mother listen-in, and they
were duly impressed when he told them they were getting it from KDKA
(the Pittsburgh station of the Westinghouse Co.), for was not
Pittsburgh 500 miles away! And so they, too, became enthusiastic
wireless amateurs. This new interest of the grown-ups was at once met
not only by the manufacturers of apparatus with complete receiving and
sending sets, but also by the big companies which began broadcasting
regular programs consisting of music and talks on all sorts of
interesting subjects.

This is the wireless, or radio, as the average amateur knows it today.
But it is by no means the limit of its possibilities. On the contrary,
we are just beginning to realize what it may mean to the human race.
The Government is now utilizing it to send out weather, crop and
market reports. Foreign trade conditions are being reported. The Naval
Observatory at Arlington is wirelessing time signals.

Department stores are beginning to issue programs and advertise by
radio! Cities are also taking up such programs, and they will
doubtless be included soon among the regular privileges of the
tax-payers. Politicians address their constituents. Preachers reach
the stay-at-homes. Great singers thrill thousands instead of hundreds.
Soon it will be possible to hear the finest musical programs,
entertainers, and orators, without budging from one's easy chair.

In the World War wireless proved of inestimable value. Airplanes,
instead of flying aimlessly, kept in constant touch with headquarters.
Bodies of troops moved alertly and intelligently. Ships at sea talked
freely, over hundreds of miles. Scouts reported. Everywhere its
invisible aid was invoked.

In time of peace, however, it has proved and will prove the greatest
servant of mankind. Wireless messages now go daily from continent to
continent, and soon will go around the world with the same facility.
Ships in distress at sea can summon aid. Vessels everywhere get the
day's news, even to baseball scores. Daily new tasks are being
assigned this tireless, wireless messenger.

Messages have been sent and received by moving trains, the Lackawanna
and the Rock Island railroads being pioneers in this field. Messages
have also been received by automobiles, and one inventor has
successfully demonstrated a motor car controlled entirely by wireless.
This method of communication is being employed more and more by
newspapers. It is also of great service in reporting forest fires.

Colleges are beginning to take up the subject, some of the first being
Tufts College, Hunter College, Princeton, Yale, Harvard, and Columbia,
which have regularly organized departments for students in wireless.

Instead of the unwieldy and formidable looking apparatus of a short
time ago, experimenters are now vying with each other in making small
or novel equipment. Portable sets of all sorts are being fashioned,
from one which will go into an ordinary suitcase, to one so small it
will easily slip into a Brownie camera. One receiver depicted in a
newspaper was one inch square! Another was a ring for the finger, with
a setting one inch by five-eighths of an inch, and an umbrella as a
"ground." Walking sets with receivers fastened to one's belt are also
common. Daily new novelties and marvels are announced.

Meanwhile, the radio amateur to whom this book is addressed may have
his share in the joys of wireless. To get all of these good things out
of the ether one does not need a rod or a gun - only a copper wire made
fast at either end and a receiving set of some kind. If you are a
sheer beginner, then you must be very careful in buying your
apparatus, for since the great wave of popularity has washed wireless
into the hearts of the people, numerous companies have sprung up and
some of these are selling the veriest kinds of junk.

And how, you may ask, are you going to be able to know the good from
the indifferent and bad sets? By buying a make of a firm with an
established reputation. I have given a few offhand at the end of this
book. Obviously there are many others of merit - so many, indeed, that
it would be quite impossible to get them all in such a list, but these
will serve as a guide until you can choose intelligently for yourself.

A. F. C.




CONTENTS


CHAPTER

I. HOW TO BEGIN WIRELESS

Kinds of Wireless Systems - Parts of a Wireless System - The Easiest Way
to Start - About Aerial Wire Systems - About the Receiving
Apparatus - About Transmitting Stations - Kinds of Transmitters - The
Spark Gap Wireless Telegraph Transmitter - The Vacuum Table Telegraph
Transmitter - The Wireless Telephone Transmitter.

II. PUTTING UP YOUR AERIAL

Kinds of Aerial Wire Systems - How to Put Up a Cheap Receiving
Aerial - A Two-wire Aerial - Connecting in the Ground - How to Put up a
Good Aerial - An Inexpensive Good Aerial - The Best Aerial That Can be
Made - Assembling the Aerial - Making a Good Ground.

III. SIMPLE TELEGRAPH AND TELEPHONE RECEIVING SETS

Assembled Wireless Receiving Sets - Assembling Your Own Receiving
Set - The Crystal Detector - The Tuning Coil - The Loose Coupled Tuning
Coil - Fixed and Variable Condensers - About Telephone Receivers -
Connecting Up the Parts - Receiving Set No. 2 - Adjusting the No. 1
Set - The Tuning Coil - Adjusting the No. 2 Set.

IV. SIMPLE TELEGRAPH SENDING SETS

A Cheap Transmitting Set (No. 1) - The Spark Coil - The Battery - The
Telegraph Key - The Spark Gap - The Tuning Coil - The High-tension
Condenser - A Better Transmitting Set (No. 2) - The Alternating Current
Transformer - The Wireless Key - The Spark Gap - The High-tension
Condenser - The Oscillation Transformer - Connecting Up the
Apparatus - For Direct Current - How to Adjust Your Transmitter. Tuning
With a Hot Wire Ammeter - To Send Out a 200-meter Wave Length - The Use
of the Aerial Switch - Aerial Switch for a Complete Sending and
Receiving Set - Connecting in the Lightning Switch.

V. ELECTRICITY SIMPLY EXPLAINED

Electricity at Rest and in Motion - The Electric Current and its
Circuit - Current and the Ampere - Resistance and the Ohm - What Ohm's
Law Is - What the Watt and Kilowatt Are - Electromagnetic
Induction - Mutual Induction - High-frequency Currents - Constants of an
Oscillation Circuit - What Capacitance Is - What Inductance Is - What
Resistance Is - The Effect of Capacitance.

VI. HOW THE TRANSMITTING AND RECEIVING SETS WORK

How Transmitting Set No. 1 Works - The Battery and Spark Coil
Circuit - Changing the Primary Spark Coil Current Into Secondary
Currents - What Ratio of Transformation Means - The Secondary Spark Coil
Circuit - The Closed Oscillation Circuit - How Transmitting Set No. 2
Works - With Alternating Current - With Direct Current - The Rotary Spark
Gap - The Quenched Spark Gap - The Oscillation Transformer - How
Receiving Set No. 1 Works - How Receiving Set No. 2 Works.

VII. MECHANICAL AND ELECTRICAL TUNING

Damped and Sustained Mechanical Vibrations - Damped and Sustained
Oscillations - About Mechanical Tuning - About Electric Tuning.

VIII. A SIMPLE VACUUM TUBE DETECTOR RECEIVING SET

Assembled Vacuum Tube Receiving Set - A Simple Vacuum Tube Receiving
Set - The Vacuum Tube Detector - Three Electrode Vacuum Tube
Detector - The Dry Cell and Storage Batteries - The Filament
Rheostat - Assembling the Parts - Connecting Up the Parts - Adjusting the
Vacuum Tube Detector Receiving Set.

IX. VACUUM TUBE AMPLIFIER RECEIVING SETS

A Grid Leak Amplifier Receiving Set. With Crystal Detector - The Fixed
Resistance Unit, or Grid Leak - Assembling the Parts for a Crystal
Detector Set - Connecting up the Parts for a Crystal Detector - A Grid
Leak Amplifying Receiving Set With Vacuum Tube Detector - A Radio
Frequency Transformer Amplifying Receiving Set - An Audio Frequency
Transformer Amplifying Receiving Set - A Six Step Amplifier Receiving
Set with a Loop Aerial - How to Prevent Howling.

X. REGENERATIVE AMPLIFICATION RECEIVING SETS

The Simplest Type of Regenerative Receiving Set - With Loose Coupled
Tuning Coil - Connecting Up the Parts - An Efficient Regenerative
Receiving Set. With Three Coil Loose Coupler - The A Battery
Potentiometer - The Parts and How to Connect Them Up - A Regenerative
Audio Frequency Amplifier - The Parts and How to Connect Them Up.

XI. SHORT WAVE REGENERATIVE RECEIVING SETS

A Short Wave Regenerative Receiver, with One Variometer and Three
Variable Condensers - The Variocoupler - The Variometer - Connecting Up
the Parts - Short Wave Regenerative Receiver with Two Variometers and
Two Variable Condensers - The Parts and How to Connect Them Up.

XII. INTERMEDIATE AND LONG WAVE REGENERATIVE RECEIVING SETS

Intermediate Wave Receiving Sets - Intermediate Wave Set With Loading
Coils - The Parts and How to Connect Them Up - An Intermediate Wave Set
with Variocoupler Inductance Coils - The Parts and How to Connect Them
Up - A Long Wave Receiving Set - The Parts and How to Connect Them Up.

XIII. HETERODYNE OR BEAT LONG WAVE TELEGRAPH RECEIVING SET

What the Heterodyne or Beat Method Is - The Autodyne or Self-heterodyne
Long Wave Receiving Set - The Parts and Connections of an Autodyne or
Self-heterodyne, Receiving Set - The Separate Heterodyne Long Wave
Receiving Set - The Parts and Connections of a Separate Heterodyne Long
Wave Receiving Set.

XIV. HEADPHONES AND LOUD SPEAKERS

Wireless Headphones - How a Bell Telephone Receiver is Made - How a
Wireless Headphone is Made - About Resistance, Turns of Wire and
Sensitivity of Headphones - The Impedance of Headphones - How the
Headphones Work - About Loud Speakers - The Simplest Type of Loud
Speaker - Another Simple Kind of Loud Speaker - A Third Kind of Simple
Loud Speaker - A Super Loud Speaker.

XV. OPERATION OF VACUUM TUBE RECEPTORS

What is Meant by Ionization - How Electrons are Separated from
Atoms - Action of the Two Electrode Vacuum Tube - How the Two Electrode
Tube Acts as a Detector - How the Three Electrode Tube Acts as a
Detector - How the Vacuum Tube Acts as an Amplifier - The Operation of a
Simple Vacuum Tube Receiving Set - Operation of a Regenerative Vacuum
Tube Receiving Set - Operation of Autodyne and Heterodyne Receiving
Sets - The Autodyne, or Self-Heterodyne Receiving Set - The Separate
Heterodyne Receiving Set.

XVI. CONTINUOUS WAVE TELEGRAPH TRANSMITTING SETS WITH DIRECT CURRENT

Sources of Current for Telegraph Transmitting Sets - An Experimental
Continuous Wave Telegraph Transmitter - The Apparatus You Need - The
Tuning Coil - The Condensers - The Aerial Ammeter - The Buzzer and Dry
Cell - The Telegraph Key - The Vacuum Tube Oscillator - The Storage
Battery - The Battery Rheostat - The Oscillation Choke Coil - Transmitter
Connectors - The Panel Cutout - Connecting Up the Transmitting
Apparatus - A 100-mile C. W. Telegraph Transmitter - The Apparatus You
Need - The Tuning Coil - The Aerial Condenser - The Aerial Ammeter - The
Grid and Blocking Condensers - The Key Circuit Apparatus - The 5 Watt
Oscillator Vacuum Tube - The Storage Battery and Rheostat - The Filament
Voltmeter - The Oscillation Choke Coil - The Motor-generator Set - The
Panel Cut-out - The Protective Condenser - Connecting Up the
Transmitting Apparatus - A 200-mile C. W. Telegraph Transmitter - A
500-mile C. W. Telegraph Transmitter - The Apparatus and Connections -
The 50-watt Vacuum Tube Oscillator - The Aerial Ammeter - The Grid Leak
Resistance - The Oscillation Choke Coil - The Filament Rheostat - The
Filament Storage Battery - The Protective Condenser - The
Motor-generator - A 1000-mile C. W. Telegraph Transmitter.

XVII. CONTINUOUS WAVE TELEGRAPH TRANSMITTING SETS WITH ALTERNATING
CURRENT

A 100-mile C. W. Telegraph Transmitting Set - The Apparatus
Required - The Choke Coils - The Milli-ammeter - The A. C. Power
Transformer - Connecting Up the Apparatus - A 200- to 500-mile C. W.
Telegraph Transmitting Set-A 500- to 1000-mile C. W. Telegraph
Transmitting Set - The Apparatus Required - The Alternating Current
Power Transformer-Connecting Up the Apparatus.

XVIII. WIRELESS TELEPHONE TRANSMITTING SETS WITH DIRECT AND
ALTERNATING CURRENTS

A Short Distance Wireless Telephone Transmitting Set - With 110-volt
Direct Lighting Current - The Apparatus You Need - The Microphone
Transmitter - Connecting Up the Apparatus - A 25- to 50-mile Wireless
Telephone Transmitter - With Direct Current Motor Generator - The
Apparatus You Need - The Telephone Induction Coil - The Microphone
Transformer - The Magnetic Modulator - How the Apparatus is Connected
Up - A 50- to 100-mile Wireless Telephone Transmitter - With Direct
Current Motor Generator - The Oscillation Choke Coil - The Plate and
Grid Circuit Reactance Coils - Connecting up the Apparatus - A 100- to
200-mile Wireless Telephone Transmitter - With Direct Current Motor
Generator - A 50- to 100-mile Wireless Telephone Transmitting Set - With
100-volt Alternating Current - The Apparatus You Need - The Vacuum Tube
Rectifier - The Filter Condensers - The Filter Reactance Coil -
Connecting Up the Apparatus - A 100- to 200-mile Wireless Telephone
Transmitting Set - With 110-volt Alternating Current - Apparatus
Required.

XIX. THE OPERATION OF VACUUM TUBE TRANSMITTERS

The Operation of the Vacuum Tube Oscillator - The Operation of C. W.
Telegraph Transmitters with Direct Current - Short Distance C. W.
Transmitter - The Operation of the Key Circuit - The Operation of C. W.
Telegraph Transmitting with Direct Current - The Operation of C. W.
Telegraph Transmitters with Alternating Current - With a Single
Oscillator Tube - Heating the Filament with Alternating Current - The
Operation of C. W. Telegraph Transmitters with Alternating Current -
With Two Oscillator Tubes - The Operation of Wireless Telephone
Transmitters with Direct Current - Short Distance Transmitter - The
Microphone Transmitter - The Operation of Wireless Telephone
Transmitters with Direct Current - Long Distance Transmitters - The
Operation of Microphone Modulators - The Induction Coil - The Microphone
Transformer - The Magnetic Modulator - Operation of the Vacuum Tube as a
Modulator - The Operation of Wireless Telephone Transmitters with
Alternating Current - The Operation of Rectifier Vacuum Tubes - The
Operation of Reactors and Condensers.

XX. HOW TO MAKE A RECEIVING SET FOR $5.00 OR LESS.

The Crystal Detector - The Tuning Coil - The Headphone - How to Mount the
Parts - The Condenser - How to Connect Up the Receptor.

APPENDIX

Useful Information - Glossary - Wireless Don'ts.




LIST OF FIGURES


Fig. 1. - Simple Receiving Set

Fig. 2. - Simple Transmitting Set

(A) Fig. 3. - Flat Top, or Horizontal Aerial

(B) Fig. 3. - Inclined Aerial

(A) Fig. 4. - Inverted L Aerial

(B) Fig. 4 - T Aerial

Fig. 5. - Material for a Simple Aerial Wire System

(A) Fig. 6. - Single Wire Aerial for Receiving

(B) Fig. 6. - Receiving Aerial with Spark Gap Lightning Arrester

(C) Fig. 6. - Aerial with Lightning Switch

Fig. 7. - Two-wire Aerial

(A) Fig. 8. - Part of a Good Aerial

(B) Fig. 8. - The Spreaders

(A) Fig. 9. - The Middle Spreader

(B) Fig. 9. - One End of Aerial Complete

(C) Fig. 9. - The Leading in Spreader

(A) Fig. 10. - Cross Section of Crystal Detector

(B) Fig. 10. - The Crystal Detector Complete

(A) Fig. 11. - Schematic Diagram of a Double Slide Tuning Coil

(B) Fig. 11. - Double Slide Tuning Coil Complete

(A) Fig. 12. - Schematic Diagram of a Loose Coupler

(B) Fig. 12. - Loose Coupler Complete

(A) Fig. 13. - How a Fixed Receiving Condenser is Built up

(B) Fig. 13. - The Fixed Condenser Complete

(C) and (D) Fig. 13. - Variable Rotary Condenser

Fig. 14. - Pair of Wireless Headphones

(A) Fig. 15. - Top View of Apparatus Layout for Receiving Set No. 1

(B) Fig. 15. - Wiring Diagram for Receiving Set No. 1

(A) Fig. 16. - Top View of Apparatus Layout for Receiving Set No. 2

(B) Fig. 16. - Wiring Diagram for Receiving Set No. 2

Fig. 17. - Adjusting the Receiving Set

(A) and (B) Fig. 18. - Types of Spark Coils for Set No. 1

(C) Fig. 18. - Wiring Diagram of Spark Coil

Fig. 19. - Other Parts for Transmitting Set No. 1

(A) Fig. 20. - Top View of Apparatus Layout for Sending Set No. 1

(B) Fig. 20. - Wiring of Diagram for Sending Set No. 1

Fig. 21. - Parts for Transmitting Set No. 2

(A) Fig. 22. - Top View of Apparatus Layout for Sending Set No. 2

(B) Fig. 22. - Wiring Diagram for Sending Set No. 2

Fig. 23. - Using a 110-volt Direct Current with an Alternating current
Transformer

Fig. 24. - Principle of the Hot Wire Ammeter

Fig. 25. - Kinds of Aerial Switches

Fig. 26. - Wiring Diagram for a Complete Sending and Receiving Set No. 1

Fig. 27. - Wiring Diagram for Complete Sending and Receiving Set No. 2

Fig. 28. - Water Analogue for Electric Pressure

Fig. 29. - Water Analogues for Direct and Alternating Currents

Fig. 30. - How the Ammeter and Voltmeter are Used

Fig. 31. - Water Valve Analogue of Electric Resistance

(A) and (B) Fig. 32. - How an Electric Current is Changed into Magnetic
Lines of Force and These into an Electric Current

(C) and (D) Fig. 32. - How an Electric Current Sets up a Magnetic Field

Fig. 33. - The Effect of Resistance on the Discharge of an Electric
Current

Fig. 34. - Damped and Sustained Mechanical Vibrations

Fig. 35. - Damped and Sustained Electric Oscillations

Fig. 36. - Sound Wave and Electric Wave Tuned Senders and Receptors

Fig. 37. - Two Electrode Vacuum Tube Detectors

Fig. 38. - Three Electrode Vacuum Tube Detector and Battery Connections

Fig. 39. - A and B Batteries for Vacuum Tube Detectors

Fig. 40. - Rheostat for the A or Storage-battery Current

(A) Fig. 41. - Top View of Apparatus Layout for Vacuum Tube Detector


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