Table Of Content

CConsial Impedance Standards ‘ho “mile of standard cable” was for 3 Tn Line the basis ar eating the raogrison quali af telephone ajurites and uelworka?"? The tle fH nape suggests Cas arta tr the old stance has sea acc plshed. This ete isa restrict sens, but with Sporn ference "The esndande here decribed coset of varying gti of gl coma ‘teasinission line strasture. Thee sole fron sty peimary eer noes of sesitnes, fncestaree,rapacitance and candcanze which are “meri somporable U iypal unknowns eacountred ib Ibaratory abi mensarerents ike the leaf satlar cable, He igi eos is ESnple stmrtialy, ite physical aostanes and dimensions may Yo aster Fried aecurfely, nad ose formulae ee avalable for srnsltiag these Per ie in leteal constants a any Hfequency ts thus an excel Pests for ti objestve. clcuable meio-trsquenry nny sana s GER, ©, and of the etic ymca range nla teal the bridge networks wed in meseuremeats onthe shart luge of cable aval- oe cheval evelpent eng, Tecra deveapmntal elim are nt usually evalable in the longer lengths on which Ue secondary constant af attenuation, phase, and ebar- terse pws tay be ieaauted ciety, borstory measurements fry eile so act aay cofaed to deteminatin of tho four diy truted primey paremecers or constants. From she the salary com ante may thea be eleuts ‘Msncurement of the dsributed primacy constants af «gives Lae steue- ur isan inst gris, exept une Ted oe retried ccumstances, Lia common 600m nuas avrg rematcaL youn JET 1951 “this ig Seca (1) a impedance bride cn do x0 more than reas the Unknow impeach cea be placed aoa its terminals; nd (2) the Tin strerare ean Te rested oly by making bridge seadings at ts input tr ertat ttre ro which pent she re dir buted series proertes ff the Ene eppear i be alleed By the shunt ropes, and vcovers. Statement (2) alo all abortions a. the ad of Seton of tans. Inision ne, except when the le ewer shest electrically Resiming shat aczurste bilge reaaensnts of the impesaner al the teists of ling ae availble steed traremisn forme may’ be {oe i eseslte gorovsly tie detubuted primary eermante, Unversity tao the accuracy of inedance badge meheurments Ind th the devlop- A tn oe hee Comma tone rent of vonxiliapedance stature ae a ans of checking the sccursey Gf test aypustes, Ae this wore poseesc, and Ce mel of the sturdanls ‘pas mone lly appresiate, Scene abou tat she ries were no merely Checker nase the coswiallandar, ut insted the bridge eleations Sree hse roy the eral stadar peda of e Coad Tag "The iri pinay consis any cena with a uniform suture nay be previey sunpuied in terms of eros and paysica constants thing formahe which save been developed by Sehekkuno? an other: Table Liana the pkyically mesure patie ase so compute the respective dstrinted eectrcal constonts, BG, aad C: cod HERE. Borage Dey © ones ee es a ‘oastan mnpemasen enustaiaot om Tele the apn Zag) 2d ator ire Zan a impacts which are of ity fer tnege eration work, however ad excep ferns ech less hen quart wave in et Z,- ave ay aml be caput ome these ‘wibuced coma enn te ears eatin "The propationcowtant and characteristic Impedance may be computed fiom the dsb anata by meen the salons 7 VORA jal) (G+ fol), and o = /E OO VE ‘vver the nomi values of the dstrbuted wneants ae of couse, pendent on tae arpropriste quanstcs as ix ‘Tabi Land the legch af the Tne, Further, for exp cousin ine teaiated ix a open cult o 4 short cieuit,respeesivay G+ jue? = ane o 2a = R > fel! = dotanhy o nostra {0} and 8 spores slate the ip pedance for aren ad aut etal iareva eons tay aril Zy bn (0) ar (Qh aad hs te the biol meas nie of he eri! rl Presi value of the apparent daebuted prinazy constants RL’ and ore the fina objective, as these quantities comprise the standards, As ig shown, they are computed fom basic data on the dclectic of the co ssa an single mea uring te ral of he ea Tes of iteee to ote Mt, leans of the ral eft uf the die treed constants on aca oer, the conductance camparent of the input scmitence of casi line bacoes ieresingly «fut ofthe den Sona and rssanice of te somuctrs ofthe Hrs, a seney fires ‘Thus ccleulsle standards of conductance ace lanes which ee went inlependen of lose i the isang neta lt support the cenler conduetor Conus Stasonung 20x Lagoxsrany Us Geert esripvios Athangh short length canis hove bor used by the Laborstoies fr some ears as ‘mpedance standacés for cable measuremette,eehaemeats ix resurrnt techniques have mace desirable to construct « ae eet of ‘standards with very uniform components und improved stuctura! quali. (02m rns aver teomvear yoursaL, sory 1984 1 ie withthe new set of impacance stanards that this paper is chilly conten The mew sandatds have fre eonstracte ir gs varying frm 3 inchs lo Lice fot in neers length soa al = elven eqaeney tl fared contin, eghtem anand izpedances ict sve "The completed standards Save been provided wid « percent sora tabinet, Fig. locate in an aircondionel able develspmest borstry tjecet to mesurenent facies The special tol develop for con- easton, sssebly, and es of the standards are ao stor in Le eabine fogeter with spre tates for maintenance ‘Each sana consi of seamless hard sn copy abe $ID. 28 cater corcutor and a straight hand drawn copper wr wennay No. 10 ‘Sets ax veer coadustor, Teflon ie expanded otesyeate i *he fer of spor cylinder, An lyaiaun tbe fe C28 ower che copper cube for roeshanical prosetion bos neulate from fe Slaivss steel tine fre povided at each end to elude dur, to facta eaaceton for i ‘lai of dy at and to pov the ser cra neccesary for Za meas resents The peje selection, and preparation of the three comp ents wre, tng and lation ea the provsion ofa repeat method fort enciting the cual re the base problams ia conection, ad sce discussed inthe flowing paragraphs, ical Contos ‘The measur plysical constants af he copper wite eed suing which ae of interest inthis spinon ae given in Table I, and thote of the Cayanded pelystyrne intltigs Sa Trble TID, Wherever practicable the mite accuracies of The mesutingdostramente wore checked aginst “eomlatystandntds of weights and motte, period rlerel to the CS Basen of Stan laboratory for cals Dimensions “The 1D shaencian quoted in able His the average af » aur af tests om en sauples of tubing ao eae obisined from dimensional and (right rlaonaipe a exe bythe equsson: 6 ‘nhcte Vie the volume of exper the sample as measured by the dian dpent teenie, the mevsued O, Df the serie and fits lenath The I. D. nasal dccmined by diet mewuranase of OD. art sal thieknes, aad agreement obtained vith the que quoted forthe abure (04 te wees owen netca, oun oy 1951 method, Vacations of weighs and cimersors alg jndivdoa!legths'of fithr ze o ung are wot signiicant as determine y cks at intervals fv mater a the Teal "Te mcaworements ie neistance aeeéed 9 determine the nsistivity cf the Zpper cowictonvate sect to litations of krwelge of teraperae ue, paricussly whens the suuples mart be meaeured in long eight Tengthe The lbouacory setup use 9 obi essa const of «ong trough shag whieh ot was crm over te iausessed samples A fetace wae Che kat of 90D gl tank of water Sa thermal contact wih the lek to uatntin Stas «ronan, oe wey slow changing erperare Miscena Avenue Dect Coe Caras Teme sau Win a CoA eee ‘i . re Contant of Reba, 0°C,| "0.0885 West aoa we A Kelvin desl bridge ed forthe ets wa operatd in acerdance with ‘rinmaaerio places Componente “he celer conductor ofeach cont ae Aan taright co that ony Fight puna soporte be used to Ke 1 ia ail alizmest wit he tube, Siow sell comical wie desing cines nonrally depend fr devon smallameter case haya Ch ce thug he Gin ining ey it ak acesary to mw te wire in the Iboretory stat stuigttt ening ule be achieve, Coramercal mactines wee, how fer ove to sau she aupply fom f° ral 29 0110" di, wie milan ‘consaAt pnaneR eran os interne amnaling. "The laboratory operation consisted of drawing the (O11 oek sta out eho 4 OK 1D, inmonel die present ss incircaty and fesse othe bre “Termine wily sae aod sown in the trade “electrolytic foxes ite” chemically compose 9993 pe ent apts DE jt ea wn 1 105 percent divided belwown sx wher laa contanitants. "hece hae alwys beer some concera az to he possbliny thet a wite ‘ren for ara suade might wel have a tit fl bard svll exer teltvely anole caves The ‘he, esetiity measurements woud then de termine a weighted average ristvty, instead ofthe surface seiivity rede for ealeulations "To lle Uns in, sts were val en ful he wie, seibhard pike as used fn commensal essa ally ane find on anaeald wie plated with a 02 mil layer of alver Tae txt con fisted of (o) comping the ae. sestance ofthe wiles by precise methods fv Ive whece Irani is ata shin dept of 2 miss end (b) microscopic uy of oun erutute of polshedtchet ere sete of the ne a tga to 2900 diameter. ‘The someon from aah sie as Than thin shin eit, ‘TRe mire therfore (eal homogeneous througout ite esas section in compton of e, restity snd em plan oa nse Copter Tabing The efecis onthe eistance nf cat eeuble to the physical com ston of theater conductor ae sel ow at S220 tha Ee ei. tren on he tg ace not a Eevere eon the wre, nwo, sa ri fr tale irae @ eenbutor’s arnebonserarnot normaly le we. Ske lain say fnve uineeetable nie mrare rouge, litt of ore, snd @ igh and variable rsisvity- Ringhrns ae lipiiy are the el fr pluses feguent aed nthe reine of ere ale bing owes ote pl ein drasng the hing to ameter. ‘at stock tubing contains psoas even gh ne parentage hogplioous may be were smal, Che orn ince the 1 Tarte The fl han! Tusing used in the coal stondnds hese dese Sows prvi! ely fo fall ane ws Lge lawn conceive Ten Fo sage castig of oxyae-tree electric copper sig elected ais vcattion apa Selptyre iee letre aera ae i te sandals sn He aici propetion are Sho fa Tale TT Te sl Zovea bas 2 ilersie constant, ey about 3% greater than thas of = and, when et (06 e ae, sven eeMTOAL yoeERAL, JOLY 1951 to nyt the coal staal inthe form of spaced lier, the com este disestris constant ie ineressed aly about 4% over theoretical for Berm in deterring the consent of the expel rated ace thus fcclee down ly abn of ay 10:1 ia thee elec on ths compete con Sant. The gure quoted for clei eostant in Table TH was obtain) by siking Inceneatal amounts of tiglcrc toa 12" length of stared ‘cova! nd pliting the meacured capeitance as increments above che “compo eapectare form ert as it Fig. 2 he stibatel conductance, (, i lerived oom the pores Sector of the leleciic hihy in Us eae of ery veaanably good mtv isso srl hot epmcnente: determination be eject to ange enor. The epparet onvhwtuce G rom (2) a the value atthe ixpu termini of te ei. [As portant fentare the standards thes Bore inet {Gathigh fequences wl, Cerfg i desble fo rar G (remava tice of she les in she diets} lo a ae 4 wn've ne psn eeder Cat ey tevorne Fxg atthe lowest ews oepeney. hit a ‘omplsho hy thet of exjied polystyrene as te deci ofthe st Polysycene is euch ralesular struct that SC i Iygrosele However under cela conditions, water vapor sna emer ol of the expand sueral i aufrentamoant to crass tar doer con cobstAL TIPEDANCR SOARS on stant and the conductance los. Par This reson al Inala ylides se brea pier! longtalially x0 that low pressure én ar my be ci clsted through the ae sbled exis when they are in he eylnders were et wi a igh sp yer, xa Ube eter hole Ale the ste qpertio, ewa deters lyse hel lets thas ccatering precou inthe casmbled coasals was ecuialal ty tat tained in tas with Ibe turned cigs of sid rates (linder spacing 5" on centers was devermined 2s absu the mesinum, pormisile to poventcetecteble sg inthe concer wie between pats of fuppore. These i pe specie strengta requirement on the cylinders except ‘that they must support the weight of Ci suaght dawn wite. Honever, = siage polyethylene disse used at te tet eu to ret ria heute which "nay ofc in making tee cornetions Fe 3-Taialy spb st ead Anny Festus Tis necesay to have mesial prolelion forthe cope tubes ofthe stander, sn this ere ee ears by a almoumn tube aipped over Th ener tbe, wih sation comeing 4 a hee! wre of UODLS 2 per flo Bet spel Io the oper nb, ‘The alin tbe i locke fn the epper tab by ahoe length of Bre tabi were tern a each fd. The wedglag action occurs when the cnd tings are stewed to the Alutsinum tube. Figure 3 isa photograp of a partially assembled standard uy Ww vegan afar sett PTs ne cvvsened. esse he elf Selig quite of he exper tae, Fd Rfece ‘eperimental dats nete tho fs coil tube i Longer than its cester conductor and the wite then lengthened incrementally ani isa lng ff the tbe, the capacitance ofthe cocial esis dectly yx le COR tw wane sine peMTeA. yoowAt, JOLY 1951 sh ln the we to bier tn O01 gf, The "eingecBect” at an recs fa ena econ cg ible The lv sents wien of the waar ae been eu: 0.500" Torr thar the tubes an he er length le! tthe test end for emetic to the test ecpment. Fs computing the fmpedanes, the lng o he tube hs been use The ODI" conor wie projection is considers ax pst of the cestectiprrt lsc and fs ete accountable ise Sion Ciresting a arte ‘A shortening of cone! tan previous develped bas beea in tne sero suler to astach shore eatin dite a he ar end wien wing the Tenth eo provide cada stieesmptance (2). Tbe use of a die Uh test meas to sort-inl Ue eer and ler coaductors witha sium snd ealuble fermi inpedener, a the cecomptshment of this objec tive by repeiahle achenical mais ab ipertan:Hetere of the nex stands “A vey thir dite preescdngrins the ed of ene seFeetve'y cane ‘acted lon, two concentric rng reresanting the pene eles wre fand tube uf dimers d and rageetivey The de ceitance of the ‘tlie asea betwoen the rng in sera of Se maintaee, ei oS pet af? i (0 reduce to: x= Zona Figuce 4 shins stoseareies of the short-ceiting vite developed fot the staan’ Figue tacky veto the eenabed dice. tr Bes of tstsaioes vel Fonsing cmyng & Urabe ike dst ad tice frst to elect a repetabley sian isan shar ctcuit whe Ue Roos i stew! To Te ead ting of Ue ecasal. "Te operation Hs 38 fellows When the ming i sere on Ue ea ting, he diss ores “guiat the end of the exppertnbe, with preesre eal Sy ar {eaves Frem the rabbae grove (hy suring te sting is abr sewed the end iting 28 fos it wil yl total pueture on the ize fe rite on iit ase fevmny iy conte of the snnutt of pajction fC tube Besa ‘heen rg.