Radio Broadcast - 1923, August - 86 Pages, 8.5 ... - VacuumTubeEra

330 Radio Broadcasthappens that its filament isoperated above or heard by the writer in Portland, Oregon include:below normal temperature. This adjustmentcan only be determined by experiment and STATIONLOCATIONAIR LINEvaries from time to time. As both the radioMILESand audio amplifier banks are connected to one KLZDenver, Colo.1035KSD St. Louis, Mo.1810plate voltage buss, their plate potentialisKFAFDenver, Colo.1035the same and appears to be best at about WDAP75 volts. The Chicago, i860detector plate voltage is a WCX 111.Detroit, Mich.2100WOCDavenport, I7IOvariable factor, but gives best results at about WSBla.Atlanta, Ga.227024 volts, when amplifier tubes are used throughout.A grid bias of from i| to 3 volts onWBAPFort Worth, Tex.|680WDAFKansastheCity Star1575WHAZaudio-frequency tubes Rensselaer, Troy, N. Y.2550prevents distortion at CHCFWinnipegI3'5that point as do also the i-megohm grid leaksUSING A LOOPconnected across the output of the audioamplifyingtransformers. As it is essential for IT is desired to use a loop, the tuning opera-consists simply of varying the secondarybest telephone reception to operate the receiver IFtionwithout local oscillation, the stabilizer is adjusteduntil this condition is obtained. The the signal is at a maximum, always keepingcondenser and the direction of the loop untiltuning now becomes nothing more than a the stabilizer down just below the oscillating.rough adjustment of the antenna circuit by Frequent voltage tests of both the A and B batteries,as well as of the filament potentials, arein conjunction with the primary condenser, essential to consistent and successful operation.means of the primary inductance tap switcha variation of coupling until a signal is heard, The " De Luxe" part of this radio receptionthen an adjustment of the secondary condenser would not be possible in auntil maximum signal is obtained. A cold garage orreductionof coupling is then advisable and slight for instance, so I have given my set an at-among a crowd of visitors in the living room,readjustments of the condensers until you have tractive and comfortable place to live in bythe signal as you want it. With a minimum of building a small room in the basement with acoupling, the receiver is most selective, and by painted linoleum floor and paneled walls androtating the secondary condenser it is possible ceilings of plaster board. Comfort is assuredto go rapidly from one station to another withoutinterference between them although they trolled) in one corner of the room, from theby an electric fireplace (thermostatically con-may be on only slightly different wavelengths. top of which appears the horn of the loudIn this respect the set is so selective that it is speaker. Reception of a sort is possible withpossible to tune out a local 5OO-watt station almost any kind of apparatus, but not the leaston 492 meters and bring in a 360 meter station enjoyable feature of it consists in being able toi ,100 miles away. Due to the radio-frequencysit in your own cozy room, listening to St.amplification there is but little loss in signal Louis, Los Angeles, or Calgary, as the notionstrength when used with a minimum of coup-happens to strike you, and knowing that youling-will not be troubled with interference ofSome of the distant broadcasting stations kind.