A. Frederick (Archie Frederick) Collins.

Experimental television; a series of simple experiments with television apparatus; also how to make a complete home television transmitter and television receiver online

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COLLINS



From the collection of the



n
m



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v



PreTinger
JUibrary



San Francisco, California
2006



EXPERIMENTAL TELEVISION



SCIENCE BOOKS

By
A. FREDERICK COLLINS



FOR ALL AGES
EXPERIMENTAL TELEVISION

8vo. 313 -f- xxi pages. Frontispiece and One Hun-
dred and Eighty-Five Text Illustrations. Index.
Price, $2.50

FOR YOUNG PEOPLE
THE BOY ASTRONOMER

8vo. 246 + ix pages. Frontispiece and One Hundred
and Seventy-Fire Text Illustrations. Index. Price,
02.00

THE BOY CHEMIST

8vo. 300 + *ix pages. Frontispiece and One Hun-
dred and Seventy-Two Text Illustrations. Index.
Price, $2.00

THE BOY SCIENTIST

8vo. 447 + xxii pages. Frontispiece and Three Hun-
dred and Forty Text Illustrations. Index. Price, $2.50



LOTHROP, LEE & SHEPARD Co., BOSTON




TELEVISION SCANNING EQUIPMENT

DESIGNED BY HOLLIS S. BAIRD



EXPERIMENTAL
TELEVISION



A SERIES OF SIMPLE EXPERIMENTS
WITH TELEVISION APPARATUS

ALSO

How TO MAKE A COMPLETE HOME TELEVISION
TRANSMITTER AND TELEVISION RECEIVER



BY
A. FREDERICK COLLINS, F.R.A.S.

INVENTOR or THE WIRELESS TELEPHONE, 1899
HISTORIAN OF WIRELESS, 1901-1910

With One Hundred and Eighty-five Text

Illustrations and Diagrams

by the Author




LOTHROP, LEE



COPYRIGHT 1932

BY LOTHROP, LEE & SHEPARD CO.
Copyright in Great Britain, the British Dominions and Possessions

All Rights Reserved



EXPERIMENTAL TELEVISION



1



PRINTED IN U. S. A,



TO

HOLLIS S. BAIRD
AMERICA'S TELEVISION GENIUS



A WORD TO YOU



A SAYING that came into play a few years ago and which is
still often heard is, "Television is just around the corner/' Now,
as a matter of fact, television is really here, and this is especially
so as far as the amateur experimenter is concerned.

As a token of the truth of this statement, I submit that there
are at the present time at least 35 licensed telecasting stations
in the United States, of which about 12 are already active, and
10 or 12 hi other countries. These stations send out television
programs nightly while thousands of lookers-in view the repro-
duced images that come to them on the transcendental wings of
short electric waves.

Nearly all these stations also broadcast the voices of the artists
who are being televised, and this adds mightily to the pleasure of
those who are looking-in at the images. These sight programs,
as they are called, are usually sent out on a shorter wave length
than the sound programs which accompany them, and, it follows,
they are telecasted and broadcasted by independent transmitters.
An exception to the above rule is the station W2XAB, of New
York, which sends sight on 107 meters, and whose cooperative
station W2XE sends sound on 49 meters.

To give you an idea, in the remote event that you do not
already know, of the sight and sound programs that are tele-
casted and broadcasted from the dual stations, here is a typical

program which I have taken from The New York Times:

vii



viii A WORD TO YOU

TELEVISION PROGRAMS

TODAY
W2XAB New York



Sight on
107 meters.



Sound on
W2XE,

49 meters.



2:00 to 6:00 Experimental program.

8:00 Sue Read, songs.

8:15 Sports parleys.

8:30 Harold Boggess, songs.

8:45 Juvenile artists.

9:00 Mystery sketch.

9:15 Ruth Kerner and Gladys Kahn, songs.

9:30 Don Sal and Franky Brown, songs.

9:45 Elliot Jaffee, tenor.

The transmission of sight and sound programs requires appara-
tus that must be very accurately designed and made, and its
operation must be in the hands of technicians who are highly
skilled in the art, but with this you do not need to concern your-
self. To belong to the ever-increasing army of lookers-in as well
as listeners-in, you must, of course, have a television receiver as
well as a radio receiver, and it has been my pleasure to tell you
how to make one with which you can get the desired results.

Now, while television is here, I would not have you believe that
the received images are perfect; nay, they are not even good, but
it is this very fact that gives the television experimenter a thrill,
for, like wireless telegraphy and telephony of yore, he has a
practically unlimited field in which to exercise his inventive
ability.

This being the way of it, I have written this book chiefly for
the amateur experimenter and based it on the scanning-disk



A WORD TO YOU ix

method the only one that is in actual use at the present time for
sending and receiving television images. Moreover, the experi-
ments are put down in sequence so that, even if you are the
veriest tyro in this new and fascinating art, you can follow them
along step by step and acquire quite a wide and useful knowledge
of the subject in the easiest and pleasantest way imaginable.

The scanning disk, though, is not the only method by which
television is, at least, theoretically possible, the chief contender
at the present moment being the cathode-ray oscillograph tube.
As this seems to be a potential successor of the scanning disk
method, I have written in a whole chapter of experiments with
it, which you will find most interesting and instructive.

The disk is a purely mechanical means of scanning, and there-
fore it possesses inertia, while the cathode ray tube is an electrical
means, and, consequently, it is inertialess. This being true, it is
easy to see that the latter possesses marked advantages over the
former in its operation and should give clearer images with an
increased scope of them. Difficulties of major importance, how-
ever, are encountered when it is applied to the actual reception
of telecasted images, but these may be overcome at any time.

Telecasting as it is practised to-day is on about the same level
as broadcasting was up to 1920, when the crystal-detector re-
ceiver was the best to be had, but with this difference, that,
whereas the scanning disk gives a more or less blurred image, the
crystal set gave a clear tone, and, whereas with the former
method any distance can be bridged, with the latter the distance
was limited to something like 100 miles.

Then, when the vacuum tube came into use, it solved the
problem of broadcasting by providing a simple and efficient way
to send out the sound programs and, at the same time, to detect



x A WORD TO YOU

and amplify them at the receiving end. From this you will
gather that what is really needed now is some scheme for scanning
that is simple and efficient, has no moving parts, and will give
clear and large images.

The engineering staffs of the great electrical concerns have
thus far failed to produce such an apparatus, and it is my private
opinion publicly expressed that when it does come and come
it must it will be the result of the genius of some independent
experimenter who possesses an inventive mind which approxi-
mates the Edison caliber.



A. FREDERICK COLLINS



CRESCENT COURT

195 CLAREMONT AVENUE
NEW YORK CITY



CONTENTS

CHAPTER I

EXPERIMENTS WITH LIGHT .... ...

The New Art of Television What Light Is How Light Vibrations Are
Set Up How Light Waves Are Set Up: What Light Waves Are
Luminous and Non-Luminous Bodies Transparent and Opaque Bodies
Light Waves Are Invisible Light Rays Travel in Straight Lines
How Light Rays Form an Image The Intensity of Light Rays How
Shadows Are Formed The Reflection of Light The Refraction of
Light The Shapes of Lenses Refraction Through a Lens What
Colors Are Colors and Their Wave Lengths How to See the Spectrum
How to Project the Spectrum.

CHAPTER II
EXPERIMENTS WITH VISION .24

What Vision Means The Eye a Television Apparatus: How the Eye Is
Made Some Experiments with Vision: Your Eye and the Camera;
An Experiment with the Field of View; How Distance Limits Vision;
Scotopic, or Night Vision; How the Eye Responds to Motion; The Per-
sistence of Vision: The Spinning Coin; The Ring of Light.

CHAPTER in
EXPERIMENTS WITH THE SCANNING DISK 41

What Scanning Means The Invention of the Scanning Disk How the
Scanning Disk Scans Some Facts About the Scanning Disk: Size and
Shape of the Light Area; Number, Size and Shape of Holes; The Speed
of the Disk; The Use of the Frame; The Direction of Rotation How to
Make a Scanning Disk How to Mount the Disk: By Using Collars;
By Using Nuts How to Run the Motor Experiments with the
Scanning Disk: The Size of the Picture; Scanning with a Beam of Light;
With a Series of Holes; With a Series of Lenses To Find the Speed of
Your Disk: With a Speed Indicator: Finding the Shaft Speed; Finding
the Surface Speed Some Other Scanning Devices: The Staggered
Scanning Disk: For Color Television; The Lens Scanning Disk; The
Scanning Drum: The Spiral-Hole Drum; The Lens Drum; The Mirror
Drum; The Scanning Belt; The Prismatic Scanning Disk.



xii CONTENTS

CHAPTER IV
EXPERIMENTS WITH THE PHOTO-ELECTRIC CELL 71

What Photo-Electric Effect Means The Invention of the Photo-Electric
Cell How Photo-Electric Cells Are Made: The Current Operated
Photo-Electric Cell: The Selenium Cell; The Vacuum Tube Cell; The Gas-
Filled Cell; The Current Generating Cell How Photo-Electric Cells
Work : The Action of the Photo-Conductive Cell: The Action of a Selenium
Cell; The Action of the Photo-Emissive Cell; The Action of the Vacuum
Cell; The Action of the Gas-Filled Cell; The Action of the Photo- Voltaic
Cell; Modern Photo-Electric Cells; The Makers of Them How Photo-
Electric Cells Are Made: The Selenium Cell Central Science Company;
The Ruggles Electric Eye; The Zworykin Caesium-Magnesium Cell; The
Burt Sodium Cell; The G. M. Visitron Cell; The Alexander K. H. Tube;
The Case Barium Silver Cell; The Wein Phototron Cell; The Rayfoto
Voltaic Cell; The Roller-Thompson Caesium Oxide-Silver Cell; The
Cambridge Cell How to Make Experimental Cells: How to Make a
Selenium Cell; Photo-Conductive Cell; How to Make a Photo-Emissive
Cell out of an Amplifier Tube; How to Make a Photo-Generating Cell;
Photo-Voltaic Cell Experiments with Photo-Electric Cells.



CHAPTER V
EXPERIMENTS WITH THE AMPLIFIER TUBE no

What an Amplifier Tube Is The Invention of the Amplifier Tube: The
Edison Effect; The Two-Electrode Tube; The Three-Electrode Tube
How the Amplifier Tube Is Made How the Amplifier Tube Is Connected
New Kinds of Amplifier Tubes: The Screen-Grid Tube; The Pentode
Tube; The Heater Tube Experiments with Amplifier Tubes: The
Edison Effect; The Fleming Two-Electrode Valve; The Three-Electrode
Tube: As a Detector; As an Amplifier Experiments with the Photo-
Electric Cell and Amplifier Tube: Coupling a Photo-Electric Cell with
a Single Stage Amplifier; The Light-Controlled Relay: The Weston
Relay; The G. M. Relay; Lighting a Lamp with a Flashlight; Lighting a
Lamp with a Match; Making an Electric Current Turn Itself Off; A Light
Actuated Counter; A Light Actuated Bell; A Public Garage Alarm;
A Light Actuated Burglar Alarm Experiments with Multi-stage
Amplifier Circuits: With a Battery Voltage Supply; With a Commercial
Voltage Supply; With a Direct Current Supply; With an Alternating
Current Supply Experiments with the Photo-cell, Scanning Disk, and
Amplifier Tube.



CONTENTS xiii

CHAPTER VI

EXPERIMENTS WITH GLOW TUBES AND NEON LAMPS . . . . 143

What a Glow Tube Is What a Neon Lamp Is: The Disco very of Neon;
The Invention of the Neon Lamp How Neon Lamps Are Made Why
Neon Is Used in the Lamps How the Neon Lamp Works Experi-
ments with Glow Tubes: Experiments with the Electric Spark; Experiments
with the Vacuum Tube; Experiments with the Neon Lamp: The Light
of the Neon Lamp; Telegraphing with Neon Lamps; The Neon Lamp
as a Voltage Indicator; The Neon Lamp as a Flasher; The Neon Lamp
as a Photo- Electric Cell; Changing Light Waves into Sound Waves; The
Neon Lamp as an Oscilloscope; To Determine the Volt- Ampere Charac-
teristic of a Neon Lamp; To Determine the Light-Current Characteristics
of a Neon Lamp; To Measure the Intensity of the Light of a Neon Lamp;
The Neon Lamp as a Rectifier and a Detector; The Neon Lamp as a
Tuning Indicator; The Neon Lamp as a Wave-Meter Connecting the
Neon Lamp with the Amplifier Tube Experiments with the Neon Lamp
and Scanning Disk: The Neon Tube and Scanning Disk; Magnifying
the Image; Magnifying and Reflecting the Image How to Make a
Demonstration Television Set: The Mechanical Equipment: The Motor
Drive; The Electrical System; To Operate the Television Set.



CHAPTER VII
EXPERIMENTS WITH ELECTRIC WAVES 187

Sending Television Impulses by Radio What Electric Waves Are The
Discovery of Electric Waves Experiments with Electric Waves: Experi-
ments with the Spark Coil: The Hertz Apparatus; The Hertz Experiments;
The Marconi Apparatus; The Marconi Experiments Experiments in
Tuning: A Pendulum Analogue of Tuning; Mechanical and Electrical
Tuning: Damped Mechanical Vibrations and Periodic Sound Waves;
Sustained Mechanical Vibrations and Continuous Sound Waves; Damped
Electrical Oscillations and Periodic Electric Waves; Sustained Electrical
Oscillations and Continuous Electric Waves Experiments in Resonance:
Simple Acoustic Resonance; Sympathetic Acoustic Resonance; Simple
Electric Resonance; Sympathetic Electric Resonance Experiments
with the Electron-Tube Oscillator: To Set Up Sustained Oscillations;
How to Tune the Oscillator Circuits; How to Find the Frequency of the
Oscillations; A Simple Continuous- Wave Transmitter; How to Connect
an Oscillator Tube with a Photo-Electric Cell Experiments with an
Electron-Tube Detector: How to Detect Sustained Oscillations; How to
Detect Conductive Oscillations; How to Detect Oscillations by Electro-
magnetic Induction; How to Receive and Detect Electric Waves; How to
Connect a Detector Tube with a Neon Tube.



xiv CONTENTS

CHAPTER VIII

EXPERIMENTS IN SYNCHRONISM 217

The Meaning of Isochronism and Synchronism Analogues of Isochronism
and Synchronism: With Swinging Pendulums; With Rotating Disks
Kinds of Synchronization Schemes: Mechanical, Electromechanical and
Electric Experiments with Mechanical Synchronizers: Finger-Friction
Speed-Control; Friction-Clutch Speed-Control; Cone Pulley Speed-Control;
Friction-Drive Speed-Control Experiments with Electromagnetic
Synchronizers: The Electromagnetic Lever-Brake; The Electromagnetic
Disk-Brake; The Push-button Resistance-Control; The Automatic Relay
Synchronizer; The Automatic Tuning-Fork Synchronizer Experiments
with Synchronous Electric Motors: Power Line Synchronous Motors;
How a Simple Synchronous Motor Is Made: The Toothed- Wheel or
Phonic- Wheel Motor; How a Constant-Speed Power Synchronous Motor
Is Made; How a Variable- Speed Induction Motor Is Made; How a Self-
Starting Variable Speed Motor Is Made; The Phonic- Wheel Control of the
Driving Motor: How the Phonic-Wheel Control Operates; How to
Synchronize a Heavy Reproducing Disk: The Push-Button Control; The
Synchronizing Coupling; Types and Prices of Motors: Oscillators.

CHAPTER DC

How TO MAKE A TELEVISION TRANSMITTER 250

About Telecasting Stations How to Make a Simple Radio Television
Transmitter: The Television Transmitting Unit: The Source of Light; The
Scanning Disk; The Synchronous Motor; The Photo-Electric Cell; The
Amplifier Tubes; The High Resistance Units; The Filament Rheostats;
The A or Storage Battery; The B or Plate Batteries; The C or Grid Dry
Cells The Radio Transmitting Unit: The Radio-Frequency Transformer;
The Oscillator Tube; The Filament Rheostat; The Fixed Condensers; The
Radio-Frequency Ammeter; The A or Storage Battery; The B or Plate
Battery How the Television Transmitter Works: The Television Unit;
The Radio Unit-

CHAPTER X

How TO MAKE A TELEVISION RECEIVER 265

About Television Receiving Sets How to Make a Simple Radio Television
Receiver: The Radio Receiving Unit: The Tuning Inductance Coil; The
Variable Condenser; The Detector Tube; The Amplifier Tubes; The Fila-
ment Rheostats; The Fixed Condensers; The Grid-Leak Resistor; The
Coupling Resistors; The A or Storage Battery; The B or Plate Batteries;
The Neon Lamp; The Neon Lamp Battery; The Television Receiving Unit:
The Neon Lamp; The Reproducing Disk; The Lens System; The Syn-
chronous Motor How the Radio Television Receiver Works: The Radio
Unit; The Television Unit-



CONTENTS xv

CHAPTER XI
EXPERIMENTS WITH CATHODE RAYS AND THE OSCILLOGRAPH TUBE . .281

Discovery of Cathode Rays Experiments: Light Effect of Cathode Rays;
Fluorescent Effect of Cathode Rays; Heating Effect of Cathode Rays;
Shadow Effect of Cathode Rays; Unidirectional Effect of Cathode Rays;
Magnetic Effect of Cathode Rays; Electrostatic Effect of Cathode Rays
What the Oscillograph Tube Is: How the Tube Is Made; How the Tube
Works Experiments with the Oscillograph Tube: With 110- Volt Direct
Current; With 110-Volt Alternating Current: With the First Pair of Coils;
With the Second Pair of Coils; With Both Pairs of Coils; With the Coils in
Series; With the Coils in Parallel; With Currents of Equal Line Wave Form;
With Currents of Different Wave Forms and the Same Frequency; With
Currents of Different Wave Forms and Different Frequencies Television
With Cathode Rays: The Cathode-Ray Television Tube: About Hot-
Cathode Ray Tubes; The Hot-Cathode Ray Television Tube: How the
Tube is Made; How the Tube Works; the Zworykin Cathode-Ray Television
System: The Cathode-Ray Tube Transmitter; The Cathode-Ray Tube
Receiver.



ILLUSTRATIONS



Television Scanning Equipment Designed by Hollis S. Baird Frontispiece

PAGE

FIG. i Diagram of an Atom Built up of Electrons and Protons . 3

FIG. 2 Making a Light by Chemical Reaction 4

FIG. 3 Making a Light with Electricity 5

FIG. 4 Free Waves in a Rope 7

FIG. 5 Circular Waves in Water 8

FIG. 6 Spherical Sound Waves in Air 9

FIG. 7 Spherical Light Waves in Ether 10

FIG. 8 Light Rays Travel in Straight Lines n

FIG. 9 How Light Rays Form an Image 13

FIG. 10 How Light Rays Decrease as Distance Increases . . . 14

FIG. ii The Reflection of Light Rays 15

FIG. 12 The Refraction of Light Rays 17

FIG. 13 How a Prism Refracts a Ray of Light 17

FIG. 14 Kinds of Convex Lenses 18

FIG. 15 How a Lens Refracts Light Rays 19

FIG. 1 6 How to Find the Focus of a Lens 20

FIG. 17 How to See the Spectrum 22

FIG. 1 8 How to Project the Spectrum 22

FIG. 19 The Right Eyeball, Showing its Various Muscles. . . 25

FIG. 20 A Horizontal Cross-section of the Human Eyeball . . 25

FIG. 21 Cross-section of the Retina of the Human Eye ... 27

FIG. 22 An Iris Diaphragm Shutter 29

FIG. 23 Testing Your Field of View. A. and B 31,32

FIG. 24 Testing Your Field of View 33

FIG. 25 How Distance Affects Vision 34

FIG. 26 A Test for Scotopic or Night Vision 36

FIG. 27 The Response of Your Eye to Motion . ... 37

FIG. 28 How to See Both Sides of a Coin at the Same Time . . 39

FIG. 29- How the Persistence of Vision Acts 40

FIG. 30 The Nipkow Scanning Disk 42

FIG. 31 "How the Scanning Disk Breaks up the Picture into

Elements 43

FIG. 32 How the Scanning Disk Recomposes the Picture

Elements , 44



ILLUSTRATIONS

PAGE

33 The Proportions of the Scanned Picture 45

34 How to Lay Out a Scanning Disk. A., B., C., and D.

49, 5 5i S 2

35 How to Mount the Disk (By Using Collars) .... 54

36 How to Mount the Disk (By Using Nuts) .... 55

37 How to Connect up the Motor 56

38 How the Light Area is Formed of Curved Lines of Light.

A. and B 56,57

39 Scanning with a Beam of Light 58

40 Indicators for Finding the Speed of a Motor or Disk . . 61

41 The Staggered Scanning Disk 62

42 A Staggered Disk Scanner with Radial Slotted Disk and

Spiral Disk . . 64

43 The Drum Scanner with Lenses 65

44 The Mirror Scanning Wheel . .... . . . 66

45 The Scanning Belt 67

46 The Prism Scanning Disk . .',;.: 69

47 The Bell Radiophone 72

48 Hertz's Classic Photo-Electric Experiment . 1 73

49 Hollwach's Photo-Electric Apparatus. ...... 74

50 Elster and Geitle's Photo-Electric Cell . ' \< . . . 75

51 The Selenium Cell .....*..... 77

52 The Photo-Emissive Cell . . . . . .' . . . 79

53 The Photo- Voltaic Cell . 80

54 How a Photo-Emissive Cell Works 81

55 The G-M Visitron Photocell 85

56 The K-H Photocell 87

57 The Cambridge Photocell 89

58 How to Make a Selenium Cell 91

59 How to Make a Photo-Emissive Cell 92

60 How to Make a Photo-Voltaic Cell 94

61 Testing the Light Activity of a Selenium Cell ... 96

62 Testing the Light Activity of a Photo-Emissive Cell . 97

63 Testing the Light Activity of a Photo- Voltaic Cell. . 98

64 A Relay and How It Is Used 100

65 Set-up for Measuring the Current of a Photo-Emissive

Cell 101

66 A. Set-up for Determining the Volt-Ampere Character-

istics of a Photo-Emissive Cell 102

B. Curves showing the Volt-Ampere Characteristics of

Vacuum and Gas Filled Tubes 103

67 Measuring the Reflecting Power of Materials ... 104



ILLUSTRATIONS



PAGE



FIG. 68 Measuring the Intensity of Direct and Reflected Light . 106

FIG. 69 The Nipkow Reverted Method of Scanning .... 107

FIG. 70 The Ekstrom Inverted Method of Scanning. . . . 108

FIG. 71 The Edison Effect in

FIG. 72 The Fleming Two-Electrode Detector Tube . . . . 112

FIG. 73 The Three-Electrode Detector Tube 113

FIG. 74 A. How the Amplifier Tube Is Made; B. New Kinds

of Amplifier Tubes 115

FIG. 75 A One-Stage Radio-Frequency Amplifier-Tube Circuit . 116

FIG. 76 Set-up for Producing the Edison Effect 119

FIG. 77 Set-up for a Two-Electrode Tube Detector .... 120

FIG. 78 Set-up for a Three-Electrode Tube Detector. . . . 121
FIG. 79 A. ,Set-up for Plotting the Characteristic Curve of a

Three-Electrode Amplifier Tube 122

B. Characteristic Curve of a Three-Electrode Tube . 124

FIG. 80 Coupling a Photocell with a Single Stage Amplifier . . 125
FIG. 81 Set-up for a Pho to-Electric Relay for Opera tng any

Electrical Circuit by Means of Light 127

FIG. 82 Set-up for Lighting a Lamp with a Flashlight . . . 128

FIG. 83 Set-up for Making an Electric Light Turn Itself Off . . 129
FIG. 84 A. A Veeder Rotary Ratchet Counter; B. Set-up for a

Light- Actuated Counter; C. The Solenoid and

Counter . .130,131,132

FIG. 85 The G-M Complete Photo-Electric Relay with Source

of Light 133

FIG. 86 A Multistage Amplifying Circuit (Battery Current) . .136

FIG. 87 A Multistage Amplifying Circuit (D.C.) 136

FIG. 88 A. Diagram of a Multistage Amplifying Circuit (A.C.) ;

B. Diagram of the Transformer Circuits . . . 138, 140

FIG. 89 A Geissler Tube 146

FIG. 90 How a Neon Lamp is Made 148

FIG. 91 The Electric Discharge in Air and Gas 150

FIG. 92 A. Wiring Diagram of a Spark Coil; B. The Spark Coil

Ready to Use 153, 154

FIG. 93 The Aurora Vacuum Tube 155

FIG. 94 A. A Vacuum Discharge Tube; B. A Set of Vacuum

Discharge Tubes 156

FIG. 95 The Corona Glow Lamp 157

FIG. 96 A Set-up for Lighting a Neon Tube 158

FIG. 97 A Set-up for Telegraphing with a Neon Lamp . . . 160

FIG. 98 The Neon Lamp as a Voltage Indicator 161

FIG. 99 Set-up for a Neon Flasher 162



ILLUSTRATIONS

PAGE

FIG. 100 Working a Relay with a Neon Flasher 163

FIG. 101 How to Change Light into Sound (with Head Phones) 164

FIG. 102 How to Change Light into Sound (with a Loud Speaker) 165

FIG. 103 The Neon Lamp as an Oscilloscope ... . . . 166

FIG. 104 How to See the Wave Form of Your Voice .... 167

FIG. 105 A Set-up for Showing the Photo-Electric Action of a

Neon Lamp 168

FIG. 106 A Set-up for Plotting the Volt-Ampere Characteristics

of a Neon Lamp 168

FIG. 107 A. A Set-up for Showing the Relation of Brightness
to Current Strength; B. Relation of Brightness to

Direct Current 169, 170

FIG. 108 A Simple Shadow Photometer 171

FIG. 109 A Set-up for a Neon Lamp Rectifier or a Detector . . . 172

FIG. no The Neon Tube as an Electric Wave Detector. . . . 173

FIG. in A Neon Lamp as a Tuning Indicator and Wave Meter . 174

FIG. 112 A Simple Neon Lamp Amplifier-Tube Circuit . . . 175

FIG. 1 13 A Neon Lamp Amplifier-Tube Circuit with a Choke Coil 176
FIG. 114 A Neon Lamp Amplifier-Tube Circuit with Two Choke

Coils . .. 177

FIG. 115 A Neon Lamp Amplifier-Tube Circuit with an Audio-
Frequency Transformer . . . . . . . . . '. 178

FIG. 116 An Experiment with a Neon Lamp Scanning Disk . . 179

FIG. 117 How to Magnify the Image . . ... . . 180

FID. 118 How to Reflect and Magnify the Image 181

FIG. 119 A. A Self-Alignment Shaft-Support; B. A Simple

Demonstration Television Set . . , . -.. . 182, 183

FIG. 120 The Electric Motor * .... 184

FIG. i2i Wiring Diagram for a Simple Television Set. . . . 185

FIG. 122 Kinds of Electric Oscillations 189

FIG. 123 The Hertz Electric Wave Apparatus 191

FIG. 1 24 The Hertz Electric Wave Apparatus 192

FIG. 125 The Marconi Electric Wave Transmitter 193

FIG. 126 A Cat- whisker Electric Wave Receiver 194


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Online LibraryA. Frederick (Archie Frederick) CollinsExperimental television; a series of simple experiments with television apparatus; also how to make a complete home television transmitter and television receiver → online text (page 1 of 17)