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Show (Edited by loulae Werdrep. KdHr of Kadlo Marohandlaln.) . , I M n (MO) .J) By Following the Olsgram Anyone Should Be Able to Correctly Assemble Thla Rat. By R. B. WILDER. One fact stand out clearly among the things that w can predict for the future of radio. Either the type of receiving sets la use must radically change or the fan must learn how to operate their set In such a manner so aa not to create Interference with surrounding sur-rounding receivers. To listen in some evening la the crowded residential districts of any large city you will be amased at what you hear: Squeal and howls surround the location of every distant' station. Either the squeals must go or ths enjoyment en-joyment sad pleasure of listening to dlstsnt station wUl be taken from all f us. Most of the blame for this condition fass been foisted npon the owners of regenerative re-generative receivers. If the trutfl were known, the Improperly neutralised neutrodyne and poorly balanced superheterodynes super-heterodynes are causing more trouble than regenerative set. At the ssme time, their owner are in the bappy frame of mind that their receiver cannot can-not possibly be the cause of any disturbance. dis-turbance. For Uie good of the whole future of radio, It behooves each and every one of us to tune our sets with consideration considera-tion for others or else build sets that cannot cause Interference even if Improperly Im-properly handled. A great manv euner. by following wiring diagram anyone who haa had even a limited experience In construction of radio receivers should be able to correctly assemble the set To construct the receiver, you will need the following apparatus; Material Yeu Will Need. C 1 .0009 mfd. low loss variable condenser. con-denser. C 2 .001 mfd. low-loss variable condenser. con-denser. O .0000 mfd. vsrlahle grid condenser". con-denser". O 8 and 4 .0001 mfd. fixed mica con-den con-den sera. C 6. 6, T and 8 .006 mfd. fixed condenser. con-denser. C 9 .00029 mfd. fixed grid condenser with grid-leak mounting. T 1 superheterodyne Input transformer. trans-former. T 2, 8 and 4 Intermediate radio-frequency transformers. L 1 precision autodyne coupler. A F medium radio audio-frequency transformer. X 1 standard vacuum rube socket X 2. 8, 4, 8, 6, T and 8 standard vacuum tube sockets. J 1 snd 2 double and single-circuit telephone Jacks, respectively. R 1 2-ohra rheostat. ,. It 2 potentiometer, 400 ohms. - M 1 H-megohm grid leak. M 2 0 megohm grid leak. M 8 .009 megohm resistor. M 4 H megohm resistor. M 8 and M6U megohm resistors. T 8 radio-frequency transformer, 200 to COO meters. S filament battery switch. V 1 and 2 loop binding peats, V 8 negative A battery. V 4 positive A battery. V 8 negntlve B battery, V 6 positive 05-volt tap on B battery. V 7 positive 13!T-voIt B battery. The seven binning poets are necessary neces-sary for the loop and battery connections. connec-tions. These should be mounted on a bakellte or hard robber binding-post strip and supported to the baseboard by means of small brass brackets. The receivers can he assembled on a panel T by 24 Inches with a baseboard 9Vfc by 22 by 1 V Inches. Uss With 8plrsl Loop. The receiver should be used with a spiral-type loop which will cover the broadcast range when tuned with a .00OB variable condenser. TJV 201 A or C 301 A types should be used throughout through-out and It Is sugitested that you try shifting the tubes around In the sockets sock-ets to find the arrangement that works best. Turn the loop aerial In the direction of the stations yon wish to receive Bnd slowly move hoth condenser dials over the scale until the sltmal from a station Is picked up. Increase the settings set-tings of the potentiometer and the variable grid enndr-nser ur.tll maximum signal strength Is received. heterodyne receivers can be classed among the worst offender and the worst squeiders. Interference le Obvlsted. A new type of super-heterodyne, as devised by Laurence M. Cockaday, positively will not radiate energy and Interference with other receiving sets. In addition, t'.ie receiver effects the saving of two tubes and will be capable of bringing In stations with loud speaker speak-er volume from distances up to 1,500 miles with a loop aerial. The first tube amplifies the current t radio frequency and also performs double duty by again amplifying the current at audio frequency. Tills tube stops the feeding of energy back Into the loop and makes the receiver non-radlatlng. non-radlatlng. The second tube acts ss both a detector de-tector and a heterodyne oscillator, thereby dispensing with another tube. The next three tubes are Intermediate frequency amplifiers that operate on approximately 2,200 meters. The next tube Is a detector, the output of which Is reflexed back Into the first tube. The stages of resistance coupled audio frequency amplification are used to increase the volume. The use of resistance amplification eliminate considerable distortion and gives the receiver a remarkable tone quality. Two dials are used In tuning the receiver, the settings of one closely j following the other. This makes for j simple tuning and positive logging of stations. While at first glance this maj eem to be a complicated receiver. 1 |