Chapter I: Front Matter

[Transcriber's Note: An underscore character "_" is used around text to signify italics in the _original_ text, as illustrated. It also is used to signify a subscript, used frequently in technical descriptions. For example _E_{C}_ would have been originally typeset as a capital E followed by a smaller C subscript, and both would have been in an italic typeface.]

LETTERS OF A RADIO-ENGINEER TO HIS SON

BY

JOHN MILLS

Engineering Department, Western Electric Company, Inc.,

Author of "Radio-Communication," "The Realities of Modern Science," and "Within the Atom"

NEW YORK

HARCOURT, BRACE AND COMPANY

COPYRIGHT, 1922, BY

HARCOURT, BRACE AND COMPANY, INC.

PRINTED IN THE U. S. A. BY

THE QUINN & BODEN COMPANY

RAHWAY, N. J.

TO

J. M., Jr.

CONTENTS

1 Electricity and Matter 3

2 Why a Copper Wire Will Conduct
Electricity 9

3 How a Battery Works 16

4 The Batteries in Your Radio Set 27

5 Getting Electrons from a Heated Wire 34

6 The Audion 40

7 How to Measure an Electron Stream 48

8 Electron-Moving-Forces 57

9 The Audion-Characteristic 66

10 Condensers and Coils 77

11 A "C-W" Transmitter 86

12 Inductance and Capacity 96

13 Tuning 112

14 Why and How to Use a Detector 124

15 Radio-Telephony 140

16 The Human Voice 152

17 Grid Batteries and Grid Condensers for
Detectors 165

18 Amplifiers and the Regenerative Circuit 176

19 The Audion Amplifier and Its Connections 187

20 Telephone Receivers and Other
Electromagnetic Devices 199

21 Your Receiving Set and How to Experiment 211

22 High-Powered Radio-Telephone
Transmitters 230

23 Amplification at Intermediate
Frequencies 242

24 By Wire and by Radio 251

Index 263

LIST OF PLATES

I One of the Lines of Towers at Radio Central
Frontispiece

II Bird's-Eye View of Radio Central 10

III Dry Battery for Use in Audion Circuits,
and also Storage Battery 27

IV Radiotron 42

V Variometer and Variable Condenser of
the General Radio Company. Voltmeter
and Ammeter of the Weston Instrument
Company 91

VI Low-Power Transmitting Tube, U V 202 106

VII Photographs of Vibrating Strings 155

VIII To Illustrate the Mechanism for the
Production of the Human Voice 170

IX Western Electric Loud Speaking
Receiver. Crystal Detector Set of the
General Electric Co. Audibility Meter
of General Radio Co. 203

X Audio-Frequency Transformer and
Banked-Wound Coil 218

XI Broadcasting Equipment, Developed by
the American Telephone and Telegraph
Company and the Western Electric Company 235

XII Broadcasting Station of the American
Telephone and Telegraph Company on the
Roof of the Walker-Lispenard Bldg. in
New York City where the Long-distance
Telephone Lines Terminate 250

LETTERS OF A RADIO-ENGINEER TO HIS SON