. Amateur radio : how and why of wireless with complete instructions on operation of receiving outfits . cturers,accordingly, make the cores permanent mag-nets by making them of steel, thus always ex-erting a pull on the metal diaphragm, but notenough to pull it to the magnets. (SeeFig. 6.) When the feeble radio current arrives atthe telephone all the energy is used in mag-nifying the attraction that the magnet exertson the diaphragm. This diaphragm is an ex-ceedingly sensitive piece of the phonemechanism. It takes very little energy tomove it. Telephone receivers will not work with al-ternati
. Amateur radio : how and why of wireless with complete instructions on operation of receiving outfits . cturers,accordingly, make the cores permanent mag-nets by making them of steel, thus always ex-erting a pull on the metal diaphragm, but notenough to pull it to the magnets. (SeeFig. 6.) When the feeble radio current arrives atthe telephone all the energy is used in mag-nifying the attraction that the magnet exertson the diaphragm. This diaphragm is an ex-ceedingly sensitive piece of the phonemechanism. It takes very little energy tomove it. Telephone receivers will not work with al-ternating current. The current moving inone direction would neutralize the currentmoving in the opposite direction and therewould be no vibration of the the ether waves, which are alternat-ing currents, must be changed to pulsating di-rect current. This is done either by means ofa crystal or audion detector. The average beginner regards a pair of re-ceivers as a couple of metallic boxes with hardrubber ear caps. Receivers all look more orless alike, but there is a vast difference on the. Fig. 6Fig. 6—Diagram of Telephone Receiver, Showing the Positionsof the Diaphragm at Different Stages of Magnetic Shows Normal Position of the Diaphragm. B. Shows Posi-tion of Diaphragm When it is Attracted to the Magnet by theIncoming Signals. C. Shows Position of Diaphragm Whenit Springs Back at the End of the Oscillation, AMATEUR RADIO 21 inside. A receiver to really work right shouldbe wound with very fine copper wire, as thewhole theory of the radio receiver hinges onthe fact that there must be a great many turnsof wire very close to an iron core. While receivers are rated by the resistancethat they have, this method of classifying themis entirely wrong. As stated above, the re-ceiver must have these turns of fine wire aboutthe pole pieces of the magnets, and in orderto get this a great quantity of wire has to beused. The easiest way to rate the receiver isby t
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectradio, bookyear1922
