14. The Receiving Apparatus
While some wireless systems employ separate antennæ for sending and receiving the messages, the same antenna is used for both purposes in most cases, and we may, therefore, describe the receiving apparatus in the inverse order of the transmitting system.
Art. 5 explains how the oscillations are set up in the receiving antenna and, also, how they must be adjusted
Fig. 11.—Microphone with Telephone Receivers Connected.
to the same frequency as that of the passing waves from the transmitting station. Referring to Fig. 3, C' represents the antenna connected through the adjustable inductance I'. Adjustably connected with this inductance is also a small capacity, called a condenser, which with the inductance forms a closed oscillating circuit. The vibratory motion in the antenna is adjusted by moving the connection y. The frequency of the closed circuit is adjusted by changing the position of point x. In
