. Practical wireless telegraphy; a complete text book for students of radio communication . rs.—The receiving detectorsof wireless telegraphy dififer greatly both in point of mechanical construction andmode of operation, and, in addition, they possess widely varying degrees of sen-sitiveness. Certain types, for instance, are highly sensitive to electrical oscilla-tions but are difficult to keep in permanent adjustment; others are less sensitivebut possess marked degrees of stability. Still others are in the nature of a com-promise and may occupy approximately a position midway between the twoe
. Practical wireless telegraphy; a complete text book for students of radio communication . rs.—The receiving detectorsof wireless telegraphy dififer greatly both in point of mechanical construction andmode of operation, and, in addition, they possess widely varying degrees of sen-sitiveness. Certain types, for instance, are highly sensitive to electrical oscilla-tions but are difficult to keep in permanent adjustment; others are less sensitivebut possess marked degrees of stability. Still others are in the nature of a com-promise and may occupy approximately a position midway between the twoextremes. Some receiving detectors rely upon the principal of rectification (as we havealready shown) and will convert an alternating current of radio-frequency to auni-directional current; others have the property of rectification combined withthe ability to vary a local source of battery current in a manner much similar tothe working of an ordinary telegraph relay. The operation of certain other detec-tors is based upon the influence of electrical oscillations upon magnetized iron or. 160—Detector Holder for Galena and SiliconCrystals. RECEIVING CIRCUITS, DETECTORS, TUNING APPARATUS. 141 upon the ability of these oscillations to cause certain granulated metals to cohere. Perhaps the most highly developed of all receiving detectors are the vacuumtube rectifiers which are extremely sensitive and possess the important propertyof amplifying the signals when connected in cascade. Certain types of vacuumamplifiers will remain in a sensitive state of adjustment over an indefinite periodor throughout their length of life. It should be kept in mind that the most sensitive receiving detector is not always theone most convenient or the most practical for commercial use. For instance, extremelysensitive amplifying detectors may require intricate apparatus, having so many points ofadjustment that its manipulation may call for the services of a highly skilled engineer andfurther the cir
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1917
