. QST . able capacitors at the lowerright are used in frequency-compensat-ing circuits for the dummy antennaand wattmeter voltage-divider. value when different loads are connected to theoutput terminals. The ballast, a GE 15-\vatt 120-volt miniature-base lamp, would seem to be aworth-while addition to such a bridge when noother means is used for keeping the input voltageconstant (the imiwrtance of this has been stressedmany times in both QST and the Hamlbook, whenreasonable accuracy is to be attained in ). A three-position switch is used for the variousfunctions. In one positi
. QST . able capacitors at the lowerright are used in frequency-compensat-ing circuits for the dummy antennaand wattmeter voltage-divider. value when different loads are connected to theoutput terminals. The ballast, a GE 15-\vatt 120-volt miniature-base lamp, would seem to be aworth-while addition to such a bridge when noother means is used for keeping the input voltageconstant (the imiwrtance of this has been stressedmany times in both QST and the Hamlbook, whenreasonable accuracy is to be attained in ). A three-position switch is used for the variousfunctions. In one position the instrument, a0-1 milliammeter, is connected to the line for power measurement. In this posi-tion the bridge and output connector aredisconnected. In the second switch position boththe dummy load and bridge are connectedto the input terminals and the milliammeter isswitched to the bridge-indicator circuit, while theoutput terminals are still disconnected. This posi-. tion permits adjusting the meter reading to fullscale for subsecjuent measurement. Thethird switch position adds a connection betweenthe bridge and the output terminals, giving reading. Since the dummy antenna is per-manently connected in all three switch positionsand the bridge is of the low-power type, theMatchmaster cannot be left in the line aftertests and adjustments have been made. The dummy antenna is specified to have astanding-wave ratio of or less at all fre-quencies up to 30 Mc, and the power meter wallgive useful readings at frequencies between500 kc. and 30 Mc. — QSL BUREAU The function of the ARRL QSL Bureau systemis to faciUtate delivery to amateurs in the UnitedStates, its possessions, and Canada of those QSLcards which arrive from amateur stations in otherparts of the world. Its operation is made possibleby volunteer managers in each W, K and YE callarea. All you have to do is send your QSL man-ager (see list be
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectradio, bookyear1915
