Wireless Telegraph Construction For Amateurs

_Frontispiece._ *Plate I. Electrical Conventions.* ................ Fig 1. Hertz Oscillator and Resonator. ............................ Fig. 2. Hydraulic Oscillator. ..............

Being desirous of keeping this book as far as possible within the limits prescribed by the title, it is not possible to go deeply into the theory of the propagation of electric...

It is generally the receiving apparatus which first attracts the attention of the amateur operator, and so it will be considered first here. An efficient receiving set consists...

The aerial or antenna ordinarily consists of a number of wires elevated in the air to emit or intercept the Hertzian waves. In fitting up a wireless station the location and ere...

The induction coil consists of a primary coil of wire wound around a central iron core and surrounded by a secondary coil consisting of many thousand turns of carefully insulate...

We now come to what is the greatest source of trouble and annoyance in an induction coil, namely the interrupter. Too much importance cannot be attached to this instrument, for...

Where alternating current is available in commercial wireless telegraph stations, the induction coil has been gradually superseded by the more modern transformer for charging th...

A condenser consists of two conducting surfaces separated by an insulator or dielectric. Fig. 53 shows a diagram of a simple condenser in which _A_ and _B_ are two tinfoil sheet...

To obtain a good oscillatory discharge with little damping it is necessary that the resistance of the circuit should be kept low, and since the greatest part of the resistance i...

The transmitting helix or tuning coil supplies the greater part of the inductance which is so necessary for the production of electrical oscillations in the transmitting circuit...

THE keys used in wireless work differ from those used in commercial wire telegraphy in being much heavier and stronger, so as to conduct and break the heavier currents without h...

Low powered stations using an induction coil as a transmitter will find a 250-volt double pole, double throw porcelain base switch to be suitable. Such a switch is connected up...

When a current passes through a conductor, it generates heat in proportion to the resistance offered and the amount of current flowing. Heat causes metals to expand sufficiently...

The purpose and position of the detector in a wireless telegraph system has already received some notice in the first chapter, but its operation and adjustment are so important...

Fig. 121 illustrates a double slide tuner. The base is a piece of hard wood, 12 inches long, 1 inch thick and 5 1/2 inches wide. Two wooden heads 4 x 4 x 3/4 inches support the...

Condensers play an important part in tuning and adjusting the receiving circuits of a wireless telegraph station. They are inserted in the circuits for various purposes. In some...

The only type of receiver of much service in wireless telegraphy is that known as a watch case or pony receiver. It is small and compact so that it may be attached to a headband...

In some cases, the intending wireless operator has had some experience with a Morse sounder and then it is merely a matter of transition and of accustoming the ear to a new soun...

On August 13, 1912, Congress enacted a "Wireless Law" to regulate radio communication. The whole law may be found in the appendix of this book, but briefly as far as the amateur...