. An elementary manual of radiotelegraphy and radiotelephony for students and operators . amount to as much as anampere or even several amperes persquare centimetre. If, then, an incan-descent lamp made as described hasits filament rendered incandescent bya continuous current, and if anothercircuit is formed outside the lampconnecting the negative terminal ofthe filament with the insulated metalplate or cylinder in the bulb, and ifoscillations are set up in this circuit,negative electricity will be able to move through this circuitfrom the filament to the plate inside the bulb, but not in the
. An elementary manual of radiotelegraphy and radiotelephony for students and operators . amount to as much as anampere or even several amperes persquare centimetre. If, then, an incan-descent lamp made as described hasits filament rendered incandescent bya continuous current, and if anothercircuit is formed outside the lampconnecting the negative terminal ofthe filament with the insulated metalplate or cylinder in the bulb, and ifoscillations are set up in this circuit,negative electricity will be able to move through this circuitfrom the filament to the plate inside the bulb, but not in the opposite , if an ordinarycontinuous current gal-vanometer is includedin the external part ofthis last-named circuit,it will give a deflectionwhen oscillations areset up in that this purpose theauthor employs a smallincandescent lamp witha rather thick carbonfilament, or better still,a double or treble fila-ment, taking altogetherabout 2 amperes at aFig. 19. terminal voltage of 12 volts. The filamentmust be so constructed that it is brightly incandescent when. OSCILLATION DETECTORS !2I J2 volls are applied to the terniinals of tlio lamp, or, t<j \\m alamp maiiufaciiirers phrase, the filament miiHt he workiii;^ at auellicienoy of at le;ist 3 watts per caudle. Auuther c«jil inwhich oscillations aro beiu<; set up is then connected with thene^ative terminal of the tilament and the external terminal ofthe metal cylinder. This circuit alsci includes a sensitive j^alvano-meler, relay, or telephone. On setting up (»scillations in thatcircuit they will he rectified, and the galvanometer will give asteady deflection as long as the oscillations last. lu using this oscillation valve or glow lamp detector as areceiving arrangement in radiotelegraphy, the author places thevalve, O, in series with therelay or galvanometer, G, inthe secondary circuits of anoscillation transformer, theprimary circuit, f, of whichis inserted in between the re-ceiving antenna and
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1916
