Fig. 73.--How the Heterodyne Receptor Works
Fig. 74.--Separate Heterodyne Oscillator
(A) Fig. 75.--Apparatus for Experimental C. W. Telegraph Transmitter.
(B) Fig. 75.--Apparatus for Experimental C. W. Telegraph Transmitter.
Fig. 76.--Experimental C. W. Telegraph Transmitter
Fig. 77.--Apparatus of 100-mile C. W. Telegraph Transmitter
Fig. 78.--5- to 50-watt C. W. Telegraph Transmitter (with a Single Oscillation Tube)
Fig. 79.--200-mile C. W. Telegraph Transmitter (with Two Tubes in Parallel)
Fig. 80.--50-watt Oscillator Vacuum Tube
Fig. 81.--Alternating Current Power Transformer (for C. W. Telegraphy and Wireless Telephony)
Fig. 82.--Wiring Diagram for 200- to 500-mile C. W. Telegraph Transmitting Set. (With Alternating Current.)
Fig. 83.--Wiring Diagram for 500- to 1000-mile C. W. Telegraph Transmitter
Fig. 84.--Standard Microphone Transmitter
Fig. 85.--Wiring Diagram of Short Distance Wireless Telephone Set. (Microphone in Aerial Wire.)
Fig. 86.--Telephone Induction Coil (used with Microphone Transmitter).
Fig. 87.--Microphone Transformer Used with Microphone Transmitter
Fig. 88.--Magnetic Modulator Used with Microphone Transmitter
(A) Fig. 89.--Wiring Diagram of 25--to 50-mile Wireless Telephone. (Microphone Modulator Shunted Around Grid-leak Condenser)
(B) Fig. 89.--Microphone Modulator Connected in Aerial Wire
Fig. 90.--Wiring Diagram of 50- to 100-mile Wireless Telephone Transmitting Set
Fig. 91.--Plate and Grid Circuit Reactor
Fig. 92.--Filter Reactor for Smoothing Out Rectified Currents
Fig. 93.--100- to 200-mile Wireless Telephone Transmitter
(A) and (B) Fig. 94.--Operation of Vacuum Tube Oscillators
(C) Fig. 94.--How a Direct Current Sets up Oscillations
Fig. 95.--Positive Voltage Only Sets up Oscillations
Fig. 96.--Rasco Baby Crystal Detector
Fig. 97.--How the Tuning Coil is Made
Fig. 98.--Mesco loop-ohm Head Set
Fig. 99.--Schematic Layout of the $5.00 Receiving Set
Fig. 100.--Wiring Diagram for the $5.00 Receiving Set
LIST OF ILLUSTRATIONS
Frederick Collins, Inventor of the Wireless Telephone, 1899. Awarded Gold Medal for same, Alaska Yukon Pacific Exposition, 1909
Collins' Wireless Telephone Exhibited at the Madison Square Garden, October, 1908
General Pershing "Listening-in"
The World's Largest Radio Receiving Station. Owned by the Radio Corporation of America at Rocky Point near Port Jefferson, L. I.
First Wireless College in the World, at Tufts College, Mass
Alexander Graham Bell, Inventor of the Telephone, now an ardent Radio Enthusiast
World's Largest Loud Speaker ever made. Installed in Lytle Park, Cincinnati, Ohio, to permit President Harding's Address at Point Pleasant, Ohio, during the Grant Centenary Celebration to be heard within a radius of one square
United States Naval High Power Station, Arlington, Va. General view of Power Room. At the left can be seen the Control Switchboards, and overhead, the great 30 K.W. Arc Transmitter with Accessories
The Transformer and Tuner of the World's Largest Radio Station. Owned by the Radio Corporation of America at Rocky Point near Port Jefferson, L. I.
Broadcasting Government Reports by Wireless from Washington. This shows Mr. Gale at work with his set in the Post Office Department
Wireless Receptor, the size of a Safety Match Box. A Youthful Genius in the person of Kenneth R. Hinman, who is only twelve years old, has made a Wireless Receiving Set that fits neatly into a Safety Match Box. With this Instrument and a Pair of Ordinary Receivers, he is able to catch not only Code Messages but the regular Broadcasting Programs from Stations Twenty and Thirty Miles Distant
Wireless Set made into a Ring, designed by Alfred G. Rinehart, of Elizabeth, New Jersey. This little Receptor is a Practical Set; it will receive Messages, Concerts, etc., measures 1" by ⅝" by ⅞". An ordinary Umbrella is used as an Aerial
CHAPTER I
HOW TO BEGIN WIRELESS
In writing this book it is taken for granted that you are: first, one of the several hundred thousand persons in the United States who are interested in wireless telegraphy and telephony; second, that you would like to install an apparatus in your home, and third, that it is all new to you.
Now if you live in a city or town large enough to support an electrical supply store, there you will find the necessary apparatus on sale, and someone who can tell you what you want to know about it and how it works. If you live away from the marts and hives of industry you can send to various makers of wireless apparatus [Footnote: A list of makers of wireless apparatus will be found in the Appendix.] for their catalogues and price-lists and these will give you much useful information. But in either case it is the better plan for you to know before you start in to buy an outfit exactly what apparatus you need to produce the result you have in mind, and this you can gain in easy steps by reading this book.
Kinds of Wireless Systems.--There are two distinct kinds of wireless systems and these are: the wireless telegraph system, and the wireless telephone system. The difference between the wireless telegraph and the wireless telephone is that the former transmits messages by means of a telegraph key, and the latter transmits conversation and music by means of a microphone transmitter. In other words, the same difference exists between them in this respect as between the Morse telegraph and the Bell telephone.
Parts of a Wireless System.--Every complete wireless station, whether telegraph or telephone, consists of three chief separate and distinct parts and these are: (a) the aerial wire system, or antenna as it is often called, (b) the transmitter, or sender, and (c) the receiver, or, more properly, the receptor. The aerial wire is precisely the same for either wireless telegraphy or wireless telephony. The transmitter of a wireless telegraph set generally uses a spark gap for setting up the electric oscillations, while usually for wireless telephony a vacuum tube is employed for this purpose. The receptor for wireless telegraphy and telephony is the same and may include either a crystal detector or a vacuum tube detector, as will be explained presently.
The Easiest Way to Start.--First of all you must obtain a government