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About The Oregon statesman. (Salem, Or.) 1916-1980 | View Entire Issue (Feb. 8, 1925)
I ' - ; , . WHY NOT USE SHIELDING? 1 ' " ' " ' -- - - - -. jlj , f ' ' ; , " ' ' " ': ; V;: . ''V:'' V: .:' : ' V - " ! ' : ' . . . . - . .... . ' . - , - ' i. 1 - J ' ' ' ? " " - " " " ' ' " - , - . - - . -...' - . ILveirroay Radio I; III I By HARRY J. 3IARX ' It seems" strange that tie arer agelladio fan appears to hesitate in making use of metal "B&leldtng' when builditfg sets. Examln the more -popular and most efficient manufactured receiring Jets and it 'will be found that proper shielding is incorporated in the maloirliy f tbem Surely if th manufactur ers ..with; theirejfpert engineering staff find it essential. It behoore the? fan who gonstruftts. his dtt set) to seriously consider i i its ad vantages. . ' f. . Possibly the real reason for. it's lack3 of general use, is i& the diffi-: culty of purchasing sheet - metal We Knar? We Don't 6utess I At AUtdMoPe Electrical Troubles j r Coxn? Qct Acquainted Joe Williams The Battery Man 531 Court SU -L HSEE ' , I - ISA FIHE BUY This late model Big 74 , cubic inch Harley.-David-son completely rebuilt, repaint ed, good tires, new 1925 lw. , 4 1 - ntlh .full Aleltlt equipmentt. This is a machine Priced only $185.0&.' 111 066- Harry; W, Scott - The Cycle: Man." Cash BAIsmo cm - . '' Kasy Terms . .. . 147. SOUTH COMMERCIAL STREET U. Specialized Factory STARfERS W a w H - . . 9' AT A - By 233 NORTH HIGH GTIinHT- U. small pieces. It Is only the large hardware supply hoiises that carry a stock of sheet metal and these firms are limited to the large Cit ies.' 'Radio stores except in tare cases are not handling shielding material. . ) Fortunately this, de mand is now being taken care of andjstandardsize. sheets Jn enve lopes like t panel stock ' are how available, j - - - Aluminam, copper and tin foil Bave been placed on the, market for shielding,itJnfortunately thin foil stock does not readily adapt Itself tor fastening to panel stock. Sheet 'metal, , having some degree of stiffness ' is more convenient. Phone 19S .;,:'jv-',"'WMi " J Ji.',tn., STORAGE SATTERIES j j you would be proud to own. , ! S. L. BATTERIES ON AND 'i.:.... '.fi,- ,i 1 I i ;: i j- "rV' ' 't GENERATORS PRICE THAT IS SATISFACTOUV ' , ' ' 3 - GENERAL BAXTERY OR ELECTRICAL' ' REPAIR AVORK ; , ih'e Hour or By, Schedule as Outlined I B llie Factory : ... S .. . 4 . .1. - -.. -,-.-..- fc, i: t-,--- V..' .-i.' . Battery and Electrical Service G. L. 3ATTERIE5 DT" DJMBALL ' OSINCi A'llATtCHr 1TTH TOUR RADIO RECEIVK In connectloa ,wita radio recefvei' and audio frequency ainplir . cir cuits it is possible, altbongh noi'ab solately necessary, to use a so-called C", battery. This is tru. in. pirn ticnlar if 4.: I or higher ratio. audio frequency transformers are used and if not more than 90 volts are usjed on the plates of the amplifier tabes. Tb use Of auch a C" battery, usually hiring' a. voltage of from I Yi to 4, win materially reduce the "B" battery current consumption , and may possibly Increase the clarity and volume of received signals. J The twd diagrams ilhisttate the pktiire and schematic conneetkni .of a C7 battery into the audio fre quency amplifying circuit of a radio receiver using standard FAD A audio frequency transformers, - 't -; With some typea of receiver and amplifier circuits having audio fre quency transformers with winding ratios (or the ratio of the number of primary tisTua to the tnnnber of .secondary tarns other than, 4 r: 1. there may be considerable .aignai distortion after the signal has passed through two stages . of audio fre- iquency ampufication and m case no '"C" battery is used. r Connecting Inxed eondensers c4 trom JUWl to U&C06 mjattfarad capdry across theartery binding post. This can be" held in place behind the apparatus as shown in the Il lustrations. ' t r " , J The question arises, which nie tal Bhould be used. Copper Is. 'de cidedly expensive and corrosion makes it turn green after a time, especially where soldering1 is done. Aluminum has a habit of collect ing an oxide coat which destroys the good electrical contact. Fur thermore aluminum does not lend itself to soldering within the limits of the fans equipment. . Magnetic metals such as iron cannot ; be used. , , ,. ,. ... -. , , ' j : . ; . Shielding Suggestions . For the average use behind a variable condenser , the . circular shield as shown on the right serves the purpose! la cases' where some protection between stages is de sirable the shield with a flap, as shown on the left in the illustra tion, is recommended. . : t Where shielding of this sOTt -is used, it should be electrically con nected to the rotor plates and on the ground sides of the circuit. A little more general use of shielding will do much : toward solving the body capacity problem which is characteristic of home constructed sets. ; Some manufac turers are going to the extent of completely lining the inside of the cabinets in order to entirely elim inate any possible external inter ference. Where a cabinet is lined in this manner the Shielding is as a rule directly connected to the ground terminal. Ser vice- H H W W f : i ; : ' PHONE 203. HOUTON STAKZI I7 .0 3 '' windifig of the - audio frequency transformer, may . eliminate or tre- Wuce. the transmjssion.of.the higher noises wtucn are so unpleasant, espe cially -whea reproduted ; by a ia ney loud speaker. -. A ' i Higher y ratio audio : f requeocy transformers can sometimes be im proved in their clarity of speech and music reproduction by connecting across their secondary winding a variable grid leak resistance of jjthe order of 1 megohm. u Some of the standard radio tre cerrimr sets 00 the ; market have binding posts for the connection) of tbe "V. battery, and in some cases, these binding posts are shorted either bv a metal strip or by the con netting leads. In other types of -re ceivers. ' the connection .between these "C battery binding posts is left open and the circuit must be dosed , before the receiver can j be operated successfully. This can; be dose either by a short wire or metal strip, or if one desires to use the "Cr battery, it should be connected between the two binding posts, ma rog sure that the positive lead from the battery connects to the positive C" battery binding post, and that the negative lead from the bat tery connects to the negative, UT ,-iue announcement by . Frepch people that they will install mammoth broadcasting station that can be easily heard Ini he united States, followed bv a alml lar movement in Great I?ritjLln ana tne many applications to our ntn rnTPrntriAnt fnr in on iKh kilowat stations, to say nothing! of tne numerous fire kilowat : sta tions, starts one guessing as j to the outcome. It might be i pre- uictea mat in a few years thre will be a number of large stations and no little ones at all. , Tbe recent drop In price lot radiophones to $3.00 brings them Info, the home folks class, where! one may enjoy a delightful Coia4 panionship with them and learn io know their accomplishments. I ' Maybe ydtl have heard Home sta tions announce, "We give stamp4" and have wondered whether the announcer was "lit up" or 1 was just harking; back to ,the days when he was connected with Katchum , & Sklnum's emporium No, they are hot trading stamp but radio's latest fad the " col lection 01 raaio stamps. . t In the up to date radio sbop you may purchase the new radio stamp album with' a sunolv of "Proof of Ileceptl6n Cards," These cards are tilled out and mailed to the stations heard, who 1 In -turn send you thelf ; stamps . These may be put in the printed Snaces awaiting theml -There Is Iso- a call book and log f included. ! To say the idea is sweeping the coun try is puttfhg it mildly, io say the least! ; f - "t: la"' - Dust is an enemy of the radio set. Put your set in cabinet-If you can. But if you cannot, cover it up when not In use. Clean the dust from: between the blades of your condensers, I ; usin a soft cloth or bi-ush. n.' ' i I Every bridge of poinVPf dust is like a leak1 in the buckets i For this same reason punched out can- denser plates should have- theit edges rounded off smooth.- In Radio Digest of February 7 the Bankers Life insurance ;sta tinn WH(1 'itTwit IfDntnM, ta . ia delightfully described ,hy Vera Brady snipman. - rrhe station is a commercial one & addition to the broadcast features. The idea was originated and Completed by Billy Heinz of that otganizationv Grand Opera producers have been shy ing at broadcast stations just like the old mare sed -to shy at an automobile Recently 13..radk station owners In Boston had such confidence t n- this belief that broadcasting opera would help further thau aVm tHe box receipts that they artuatl-r -tirifirwrfitfi the expense cospaBf'.t'.! I . The " ' RADIO PHAN Talks j r I i-1 : 1 , . . , ia. ' Boston - z f a Chicago operatic j i gusrsstsed- iiaj 1 i- -. . 1 I t rr" 1 1 v r I-.-: I'"1!-- ' T ; ;ij r-Hr" rft : I . -1 r- . r - . ' J- ' :,:; . .. At- , .vjass ' y. ..: -i .. - t - CORNER CHEMEKETA AND HIGH - t . -'a - -i ' 11 ri j. 1 f,i:! against any loss due to broad casting. . several n operas were broadcast and lw await with un usual interest the results. Millions Ot Dollys 5 iki I sent uacK From Germany BERL1N, h-rtei.-i f 7American currency ifent jsack ;toi tne mother iouatry at' a record irate in .124. During the Inflation1 period American- banknotes! and silver ; certifi cates and all sorts of ther Amer ican paper money were boarded. Frieads aad . relatives i remittc i bls 'asi it was tucke4:awey-wr value tlii low cost, Chevrolet now has greater "quuty tnaii everbefbfe' V , chassis from radiator to rear axle, new quality features of construction that you would expect - to find only on higher priced cargo bodies bF even gteatet beauty and coinfort. Open models have inany added refinements. Closed models with fine Fisher Bodies finish in beautiful colors "of the wonderful and ???g tDuP, that, retains, its color and, lustre iiidefimtely and1 withstands severest usa : 3 2? i i a. rainy, djy,. yhile. .the . Cermaa paper money wa fluctnaiins' a wildly nobody -waiited to fcold itj. ConseuentryalJLiortaJjXorelga stable .money was in great de mind and "American money wa th, first ..choice as .Jt..fl actuated less even t4an ifnglish pounds. 4 fow thai the" tentenmark ! ha been fairly firm for nearly1 a year accf Germaaa have general confii dc nee in ltj they t are letting go of their foreign money st a rapid v ,.v. uiuiaus aoaraea 'torjelsn gold -or ; silver are! out ok luqi, as the exchacger-Tate on it Is pxtremeiy bad. Nobody wants iiaramortey.ndLhe..(jiiC!tatIoa3.cj f: m la.ofien 20: percent below the of ficia rate for paper . money. Foreign silver is an absolute drag on.. the r money-, market. Small moneychangers who will accept It often1 shave -it 4 Oi per cent. Insurance agent got arrested id Dallas, Tex;, but not because of It. 5 1 fist! hi! GreIpf nd Towing W Gir Too Tour t3Ieaer's Wort . w t y irn-fr" 1 ...J t Guaranteed Er;ert T (I r
