. Elements of radio telephony . ductance coil Li to the groimd. Tuning may be accomphshed by var3dng either the con-denser Ci or the inductance coil Li or as is the case of a pop-ular commercial receiver both condenser and inductance arevaried simultaneously. Increasing either the capacity ofthe condenser or the inductance of the coil will increase thewave length to which the receiver is tuned, and decreasingeither or both of these values wiU shorten the wave coil L2 is connected in the plate circuit and is arrangedso that its effect on coil Li in the grid circuit may be
. Elements of radio telephony . ductance coil Li to the groimd. Tuning may be accomphshed by var3dng either the con-denser Ci or the inductance coil Li or as is the case of a pop-ular commercial receiver both condenser and inductance arevaried simultaneously. Increasing either the capacity ofthe condenser or the inductance of the coil will increase thewave length to which the receiver is tuned, and decreasingeither or both of these values wiU shorten the wave coil L2 is connected in the plate circuit and is arrangedso that its effect on coil Li in the grid circuit may be L2 is mounted inside Li and arranged so that itcan rotate inside Li, in other cases the coil L2 is woimd onthe same form as L\ and its effect upon Li controlled by aswitch which can cut in any number of turns. The effectin eithei case is the same except that where the two coils are RECEIVING EQUIPMENT 77 in fixed relation to one another, and adjustment is effectedby varying the number of turns, it is usually impossible to. Fig. 38.—Single circuit regenerative receiving set. obtain as accurate a control over the feed back and the con-sequent regeneration of the signal as is desirable. In operating a set of this character adjust the tube filamentcurrent to the proper value, then tune for the desired signalby varying the condenser and inductance coil, the plate or 78 ELEMENTS OF RADIO TELEPHONY tickler coil being adjusted somewhat below its maximumvalue. When the desired signal is heard, increase the plate-coil adjustment until the signal is amplified to its maximiunpoint. This point is just below the adjustment for the self-osciUating condition. A variation in the plate-coil adjust-ment wiU usually change the tuning of the antenna circuitand require a shght readjustment of condenser or coil tokeep the signal at maximum intensity. Where it is desiredto increase the wave-length range beyond that of the receiveralone an additional combination loading coU for grid andplate ci
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectradio, bookyear1922
