Front matter

Pl. I.–One of the Lines of Towers at Radio Central (Courtesy of Radio Corporation of America).

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

LETTERPAGE

1Electricity and Matter3

2Why a Copper Wire Will Conduct Electricity9

3How a Battery Works16

4The Batteries in Your Radio Set27

5Getting Electrons from a Heated Wire34

6The Audion40

7How to Measure an Electron Stream48

8Electron-Moving-Forces57

9The Audion-Characteristic66

10Condensers and Coils77

11A “C-W” Transmitter86

12Inductance and Capacity96

13Tuning112

14Why and How to Use a Detector124

15Radio-Telephony140

16The Human Voice152

17Grid Batteries and Grid Condensers for Detectors165

18Amplifiers and the Regenerative Circuit176

19The Audion Amplifier and Its Connections187

20Telephone Receivers and Other Electromagnetic Devices199

21Your Receiving Set and How to Experiment211

22High-Powered Radio-Telephone Transmitters230

23Amplification at Intermediate Frequencies242

24By Wire and by Radio251

Index263

LIST OF PLATES

IOne of the Lines of Towers at Radio CentralFrontispiece

IIBird’s-Eye View of Radio Central10

IIIDry Battery for Use in Audion Circuits, and also Storage Battery27

IVRadiotron42

VVariometer and Variable Condenser of the General Radio Company. Voltmeter and Ammeter of the Weston Instrument Company91

VILow-Power Transmitting Tube, U V 202106

VIIPhotographs of Vibrating Strings155

VIIITo Illustrate the Mechanism for the Production of the Human Voice170

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

XAudio-Frequency Transformer and Banked-Wound Coil218

XIBroadcasting Equipment, Developed by the American Telephone and Telegraph Company and the Western Electric Company235

XIIBroadcasting 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 Terminate250

LETTERS OF A RADIO-ENGINEER TO HIS SON