322 <strong>Radio</strong> <strong>Broadcast</strong>highest sensitivity by means of artificial signalsfrom a test buzzer. The buzzer, though preferablyof the high-frequency type, may be ofthe ordinary door-bell design, the note of whichcan often be improved by inserting a pasteboardslip between the armature and the spring contact(Fig. 6). The sole connection between thebuzzer and receiver (and no connection at allisrequired when the detector iscorrectly adjusted)is a single wire running from the stationarycontact to the ground-lead (Fig. 4).The detector should be adjusted while the keyor push-button is down, and the note of thebuzzer will be plainly audible in the receiverswhen a sensitive adjustmentis secured.The apparatus is preferably mounted ona panel after the fashion of bulb sets, withthe detector placed on the front in such amanner as to permit easy adjustment. A pushbuttonmay be set flush in the panel for operatingthe buzzer test, but many enthusiastsprefer a telegraph key on the operating table,making the buzzer additionally useful for codepractice. Care should be taken in the constructionand mounting of the instruments,in order that the crystal receiver may be giventhe finish and appearance which it merits.ADDING AN AUDION TO THE CRYSTAL RECEIVERTHEcrystal sets which have been describedemploy a tuning system that is readilyadaptable to bulb reception, it being merelynecessary to build up the bulb equipment asan auxiliary unit. The additional parts whichwill be required are: the bulb, A and B batteries,socket, rheostat, grid condenser andgrid leak, and the plate variometer. Theextra equipment should be connected as shownin Fig. 7, and is hooked up to the crystal receiverby connecting wires A' and B' to wires Aand B respectively in Figs,i or 2 after eliminatingthe detector and receivers (the phones ofcourse being transferred to the bulb circuit).FIG. 7The bulb unit for connection to iFigure and 2. Thiswill make the crystal set into a regenerative receiverFIG. 8A combination audion-crystal set, permittinginstant change to either form of detectionThe result will be an efficient regenerative receiver,which, if desired, may as easily bechanged back to a crystal set.Fig. 8 shows a combination crystal-tube setin which either form of detection is immediatelyavailable. When tube receptionis desiredand the tube is lighted, it is merely necessaryto remove the cat-whisker from its positionon the crystal. When crystal receptionis preferred, the current that lights the bulb isturned off and the cat-whisker is adjusted torest lightly on the crystal. No switches arerequired unless it is desired to keep the detectorpermanently adjusted, in which case asingle-pole single-throw switch may be placedbetween the crystal detector and the phones,thus obviating the necessity of removing thecat-whisker. The principle is quite clearlyindicated in Fig. 8, and it may be applied withequal simplicity to almost any crystal or bulbcircuit which you may at present possess.The crystal receiver iscapable of remarkableresults when constructed and operated withsome degree of "finesse" which, alas, is oftenas totally lacking in radio as in bridge. Theclose of the war found crystal receivers Coveringfifty to a hundred miles, on amateur power andwavelengths; and until much more recentlythey were used almost exclusively for commercialwork (due to patent complications onbulb apparatus), traffic being handled in manyinstances over distances of a thousand miles!Of course, you cannot expect to hear broadcastingstations a thousand miles away witha crystal set, and even fifty-mile reception maybe considered exceptional; but ifyou live withinabout twenty-five miles of a broadcasting station,you should be able to hear it consistentlyand plainly; and the music will come in withoutthe distortion so common with sets employingvacuum tubes.
Powel Crosley, Jr.ofTHE"The Henry Ford<strong>Radio</strong>"By ALVIN RICHARD PLOUGHother day I visited two largeradio plants where several hundredpeople are daily engaged in turningout radio apparatus to meet thetremendous demand for such products.When I was ushered into the office ofthe president of this enterprise,found that heIwas a much youngerman than I had expected;in fact he confessedto being thirty-six. Hisyouth impressed meand I marveled at hisability to grasp bigproblems and makequick decisions. Whatability he has along thisline, he says, has beendeveloped through themany and varied thingshe has done during hisbusiness career.Those who knewPowel Crosle'y, Jr.,President of the CrosleyMfg. Co., as a veryyoung man, refer to himas a "rolling stone"type of boy; but nowthey are glad to " handit to him" as a soundbusiness man. Such hasbeen the change in sen-comparatively inexpensive radio apparatus.Mr. Crosley told me that it was in 1921 thathe first became interested in the radio business.He considers that he owes a great deal to histhat his companyyoung son for the positionholds in the radio industry. It was on Washington'sBirthday, just two years ago, that hisboy, who was then nine years old, wanted aradio set. He took the boy to the factory ofthe Precision Equipment Company, which wasmanufacturing receiving sets and is one of theoriginal licensees under the Armstrong patent.It was Mr. Crosley's intention to buy an inexpensiveset as a toy for Powel, 3rd, but hefound that the least expensiveone cost about$130, which appearedto him to be too much ofan investment for asmall boy's toy. Theinsistence of the boywas followed by thepurchase of parts toassemble a set andnotwithstanding thelimited amount ofbroadcasting two yearsago, Mr. Crosley andhis son became ardentradio enthusiasts.Less than two yearsafter his first visit toThe Precision EquipmentCompany's factory,he purchased acontrolling interest inthat corporation, whichis now being operated asa separate organization,so that he is now at thehead of two radio man-HE FIRST BECAME INTERESTED IN RADIO TWOAND A HALF YEARS AGOufacturing companies!timent about the man NowThehe is head of two radio manufacturing companiesearly career ofwho operates the radioPowel Crosley is veryplants I visited in Cincinnati, and who has been interesting. Before going to work, his academicreferred to as "the Henry Ford of radio," becausehe builds such large quantities of good andeducation consisted of public school and militarypreparatory school, one year of engineeringwork in college and two years at law school.His first job was rebuilding some old telephonesduring a summer vacation while in thepublic schools. This was followed by work invarious phases of the automobile business duringsummer vacations from college. Duringhis last year in law school he was employed bya large bill-posting company to acquire leases