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 of some form of Detector, Tuning Coil, Telephone Receivers, and Condenser.
Other accessories such as adjustable condensers, potentiometer, battery and testing buzzer improve the outfit and make it more complete.
The choice of the type of instruments must be left entirely to the person who is constructing them. His resources will determine whether he is to use 1,000 ohm telephone receivers built especially for wireless work or ordinary ones having a resistance of only 75 ohms. It is therefore best to read carefully the chapters devoted to the different pieces of receiving apparatus and select the type of detector, tuning coil, etc., which it is desirable to use before commencing the construction of any.
For beginners, I would recommend an outfit consisting of a silicon detector, a double slide tuning coil, a condenser of fixed capacity and 75-ohm telephone receivers. Such an outfit with a 50-foot aerial will receive messages about 150 miles. If 1,000 ohm telephone receivers are used, messages may be read up to 400 miles. Much depends upon the location of the station and the ability of the operator.
A more elaborate and efficient set consists of an electrolytic or "Perikon" detector, a transforming tuner, two adjustable condensers, a potentiometer and a pair of 1,000 ohm telephone receivers. This outfit and a 75-foot aerial could be made to receive 500 to 1,000 miles by a careful operator.
Several cuts of wireless apparatus built for private installation are shown both in this chapter and further through the book, to give an idea of how the better instruments of this type are constructed and finished.
Fig. 10. Long-distance Receiving Set.
Fig. 10 illustrates a selective receiving set built by the Long Distance Wireless Company. The set is mounted on a mahogany base and the instruments are finished in polished hard rubber and lacquered brass. They comprise a detector stand so arranged that any of the sensitive minerals used in wireless work may be used. The tuning coil is of the double slide type. The condenser is sealed up in a square lacquered brass tube fitted with hard rubber ends and binding posts. The arrangement and construction of the outfit may be readily understood from the cut.
