Wireless Telegraphy and Telephony

i-::-.-:-:.-.«-:.:-.-.-.-:..:.-.--:-?.;::-;-;-:... : ... ■ CHAPTER IV. THE RECEIVING APPARATUS. The receiving instruments form the most interesting and ingenious part of a wireless station. They are the ears of the wireless station. They are wondrously sensitive but yet simple and incapable of much complication. The receiving station forms an exact counterpart of the trans- mitter, and the train of actions taking place are the reverse of those of the latter. The purpose of the transmitter is to change ordinary electric currents into electrical oscil- lations and thus set up electric waves, while the receptor converts the waves into oscillations and thence into cur- rents which are capable of manifesting themselves in a telephone receiver. The instruments necessary for re- ceiving comprise a Detector Fixed Condenser Telephone Receivers Tuning Device Other instruments such as a potentiometer, test buzzers, variometers, variable condensers, etc., complete the outfit and improve its selectivity and sensitiveness. The detector forms the most vital part of the receptor. In explaining its action it may be well to recall and enlarge upon the description already set forth on page n, where it was explained that electromagnetic or as they are more commonly called when identified with wireless telegraphy, Hertzian waves have the power of exciting oscillations in 48