Letters of a Radio-Engineer to His Son

by John Mills

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

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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

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COPYRIGHT, 1922, BY
HARCOURT, BRACE AND COMPANY, INC.

PRINTED IN THE U. S. A. BY
THE QUINN & BODEN COMPANY
RAHWAY, N. J.

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TO

J. M., Jr.

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CONTENTS
LETTER		PAGE
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]

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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]

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