Isihloko esiyisithenjwa sokugcina, esinesicefe kakhulu. Cishe akukho phuzu ekuyifundeni ukuze uthuthuke ngokujwayelekile, kodwa uma lokhu kwenzeka, kuzokusiza kakhulu.
Okuqukethwe ochungechungeni lwezihloko
Indawo yababhalisile
Ngakho, i-TV kagogo wakho iyekile ukubonakala. Umthengele entsha, kodwa kwavela ukuthi inkinga ayikho kumamukeli - okusho ukuthi kufanele uyibhekisise intambo. Okokuqala, izixhumi ezivame ukugoqa, ezingadingi ukucwiliswa, zizisonta ngokuyisimangaliso zisuke kukhebula, okuholela ekulahlekelweni kokuthintana ne-braid noma i-central core. Ngisho noma isixhumi sisanda kukhishwa kabusha, kufanele uqiniseke ukuthi azikho izinwele eziboshwe ezixhunywe kumqhubi ophakathi. Ngendlela, ububanzi be-central core ngokuvamile bukhulu ngokuphawulekayo kunembobo esokhethini yokwamukela - lokhu kuyadingeka ukuze uxhumane kahle ngenxa yamacembe akhulayo kusixhumi. Kodwa-ke, uma ngokuzumayo ushintshe isixhumi ngesinye lapho ingqikithi emaphakathi ingaphumi “njengoba injalo”, kodwa ingena enalithini (njengalezo eziboniswe yimi izixhumi ze-RG-11), noma ushintshe ingxenye yekhebula futhi entsha inomgogodla omncane, khona-ke ungase uhlangabezane neqiniso lokuthi amacembe akhathele ku-socket ngeke anikeze ukuxhumana okuhle nomgogodla ophakathi.
Lapho uthatha izilinganiso ngedivayisi, konke lokhu kungabonakala kalula kusukela ekumisekeni kwe-spectrum yesignali, engibhale ngayo . Ngale ndlela singakwazi ukuqapha ngokushesha izinga lesignali (ake ngikukhumbuze, ngokusho kwe-GOST akumele ibe ngaphansi kuka-50 dBµV yesiginali yedijithali kanye no-60 yesignali ye-analog) futhi sihlole ukuncishiswa endaweni ephansi nephezulu yefrikhwensi, okuyinto izosinika izeluleko zosesho oluqhubekayo lwenkinga.
Ake ngikukhumbuze: ukuncishiswa kwamafrikhwensi aphansi kuvame ukuhlotshaniswa nezinkinga kumongo omaphakathi, futhi ukuwohloka okukhulu kwamafrikhwensi angaphezulu kukhombisa ukuthintana okungalungile ne-braid, futhi lokhu kuvame ukuhlotshaniswa ne-crimping (kahle, noma isimo esibi jikelele se-braid). ikhebula, okuhlanganisa ubude obuningi).
Ngemva kokuhlola ikhebula ngesixhumi ku-TV, kufanelekile ukuyilandela kulo lonke efulethini: njengoba ikhebula le-coaxial lingeyona nje i-conductor kagesi, kodwa i-waveguide, alikho ngaphansi kokuphuka kanye nokunye ukulimala kwemishini, kodwa futhi liyagoba. kanye nama-kinks. Kuyafaneleka futhi ukuthola zonke izihlukanisi zesignali nokubala ukuncipha kwazo okuphelele: kungase kuvele ukuthi ngaphambi kwalokhu konke kusebenze emkhawulweni kanye nokuwohloka okuncane kwekhebula kuholele ekuqedeni ukungasebenzi. Kulokhu, ukuze ungaphinde uhambise umzila ikhebula elifihliwe ngemuva kokunquma, ungakhetha ngokuphumelelayo izilinganiso zabahlukanisi noma ufake i-amplifier encane emnyango wefulethi.
Uma kungekho kulokhu okubonwayo futhi konke kuhlelekile ngekhebula kuze kufike kuphaneli yamanje ephansi ezitebhisini, ngakho-ke kuyadingeka ukukala izinga lesignali elingena efulethini. Uma ileveli nokuma kwesiginali empompini yesihlukanisi sobhalisile kujwayelekile, khona-ke kufanelekile ukuhlola umehluko phakathi kwamanani aku-TV kanye nephaneli yokulawula bese ucabanga ngokuthi sikugejile kuphi nokuthi yini. Uma sibona ukuthi ukuncishiswa kwe-TV kwakuyinani elithile elinengqondo, kodwa ngesikhathi esifanayo sibona izinkinga ngesignali empompini, khona-ke kufanele siqhubeke.
Riser
Ngemva kokubona inkinga empompini wababhalisile, kufanele uqiniseke ukuthi isihlukanisi ngokwaso asinacala. Kwenzeka ukuthi omunye ompompi ngokushesha noma kancane kancane uwohloka amapharamitha wesignali, ikakhulukazi ezihlukanisi zenani elikhulu lababhalisile (ngaphezulu kuka-4). Ukuze wenze lokhu, udinga ukukala izinga lesignali komunye umpompi (okungcono kube kude ngangokunokwenzeka kusukela kuleyo nkinga), kanye nakukhebuli eyinhloko engenayo. Nalapha futhi, ukuqonda ukuthi isiphi isimo nezinga isignali okufanele ibe yiyo kuzofika kahle. Inani lokunciphisa empompini yokubhalisa eliboniswe kusihlukanisi ekumaka (isibonelo, 412 - 4 ompompi -12 dB ngamunye) kufanele lisuswe kulokho okukalwe emugqeni omkhulu. Ngokufanelekile, kufanele sithole isibalo esithathwe empompini yababhalisile. Uma ihluke ngaphezu kwe-dB embalwa, kungcono ukumiselela isihlukanisi esinjalo.
Uma sibona ukuthi isignali isivele ifika eduze nomgwaqo onguthelawayeka onethambeka eliqinile noma izinga eliphansi, khona-ke kuzodingeka sizijwayeze nomklamo wesikhuphukeli, noma, sisebenzisa ingqondo, silinganisele izinto ezimbili: ingabe isikhuphukeli sakhiwe ngenhla noma ngezansi nokuthi kude kangakanani negatsha eliseduze esikuso. Eyokuqala ingaqondwa ngokuthi ikhebula elixhunywe kokufakwayo kwesihlukanisi livelaphi nokuthi leyo ephuma kokuphumayo iya kuphi. Ngokuvamile akunzima ukulandelela izintambo eziyinhloko ngqo kuphaneli, kodwa uma zingabonakali, khona-ke ungaya phansi ngenhla (noma ngezansi) futhi ubone ukuthi inani elihlukanisayo likhona. Kusuka Cishe uyakhumbula ukuthi ihlelo kufanele linciphe njengoba uya phambili kusukela ekuqaleni. Lapho futhi ngabhala ngokuhlukanisa isikhuphukeli sibe izingxenye (sivame ukuzibiza ngokuthi "ama-pilaster", angiqiniseki ukuthi lokhu kuyamukelwa ngokuvamile). Ngokuvamile, i-pilaster eyodwa inweba ngaphezu kwezitezi ezingu-5-6 futhi ekuqaleni kwayo kukhona abahlukanisi abanezilinganiso ezingu-20-24 dB, futhi ekugcineni - 8-10. Uma uqiniseka ukuthi inkinga itholakala ngaphandle kwesitezi, kufanele uthole isiqalo se-pilaster futhi uthathe izilinganiso kusuka kumhlukanisi oyinhloko lapho iqala khona. Lapha izinkinga zisafana: kokubili isihlukanisi ngokwaso kanye nekhebula elimele kanye ne-crimping yekhwalithi engeyinhle kungaba nomthelela. Kwenzeka nokuthi ngemva kokuhambisa izixhumi, isignali ibuyiselwa (kodwa ngokuvamile iyanyamalala ngokuphelele). Kulokhu, kufanele uphinde ukhiphe yonke into, futhi kungaba kuhle uma abafaki, sebehlinzekele lokhu, beshiya ikhebula. Phela uma kuphinda kucwiliswe kumele kufinyezwe. Kukhebula le-RG-11, inkinga yokugwetshwa okungalungile ivame kakhulu: lokhu mhlawumbe ukwehluleka ukuhambisana nezinga lokukhumula, lapho i-central core ishiywa yinde kakhulu (ngenxa yalokho, isixhumi asihlali kahle futhi ikhebula lingagxuma liphume kuyo), noma into efanayo, kodwa ngenxa yesigaba A esikhulu kakhulu (bheka umfanekiso ngezansi).
Kuhle ukusho ngokwehlukana ukuthi ngisho nokukhumula okufanele ngeke kuvikeleke emaphutheni uma i-crimper ingahlali ngokuphelele isixhumi futhi i-central core ayingeni "inaliti" yesixhumi. Ngesikhathi esifanayo, inaliti inokuhamba uma uyinyakazisa ngomunwe wakho. Lapho umthambo usungene kahle, akunakwenzeka ukuwunyakazisa. Lokhu kufanele kuhlolelwe isixhumi ngasinye esingakrululiwe.
Abahlukanisi ngokwabo ezindlini ezineminyaka engaphezu kwe-10 bangathola lokho okwakwaziwa phakathi kwabaqoqi bemodeli njengokuthi "isifo se-zinc."
Isithombe esisuka kusayithi
Izindlu zokuhlukanisa ezenziwe ngama-alloys angaziwa futhi ezitholakala ezimweni zezulu ezimbi zingabhidlika ngokoqobo ezandleni zakho lapho uzama ukuqaqa isixhumi, noma ngisho nalapho izintambo zihamba esihlangu. Futhi ngokuvamile lokhu kwenzeka lapho abafaki besebenza kuphaneli yokulawula, behlinzeka othile nge-inthanethi, noma abanye opharetha be-intercom.
Uma isihlukanisi lapho i-pilaster iqala khona asiphukanga ngesigamu, futhi izinga lesignali kulo libi njengasefulethini, khona-ke kufanelekile ukuthola isihlukanisi lapho kuvela khona i-branching yokuqala futhi sikala isignali esiza kithi. kusukela kumishini esebenzayo esuka engaphansi (noma i-attic - njengoba yakhiwe). Ngemva kokudlula isikhuphukeli ngale ndlela futhi ungayixazululi inkinga, kuzodingeka uyofuna imishini esebenzayo futhi uthathe izilinganiso kuyo.
Imishini esebenzayo
Okokuqala, kufanelekile ukuqaphela ukuthi phakathi kwabamukeli be-optical kanye nama-amplifiers kukhona inethiwekhi yokusabalalisa, eyakhiwe ngokuvumelana nezimiso ezifanayo njengama- risers, ngakho-ke inezinkinga ezifanayo. Ngakho-ke, konke okulotshwe ngenhla kufanele kubhekwe lapha futhi, bese kusolwa kuphela ekusebenzeni kwe-hardware.
Ngakho-ke, sisendlini engaphansi (i-attic, i-switchboard enkulu), phambi kwebhokisi elinama-amplifiers
Kuyenzeka…
Uma ingekho isignali esikhuphukeni nhlobo futhi kukhona izinsolo zokuthi i-amplifier ifile, khona-ke indlela elula yokunquma ukuthi iyiphi iwukuba izinga lokushisa layo lifinyelele ekuthinteni. Ngisho nasemakhazeni amakhulu emakamelweni angashiswanga, i-amplifier esebenzayo izofudumala kunemvelo, futhi i-amplifier eshile izonuka amakhaza. Uma umehluko wokushisa ungabonakali ngokwanele, khona-ke ukuwuvula kuzobonisa ngokuqinisekile ukuthi inkomba yamandla ngaphakathi kwe-amplifier ayikhanyi. I-amplifier enjalo ithathelwa indawo eyodwa eyaziwa ukuthi iyasebenza, futhi kamuva ilungiswe kusetshenziswa isiteshi esivamile sokunamathisela, ngoba cishe konke ukwehluleka kuhlotshaniswa nama-capacitor avuvukele e-banal. Lapho ushintsha ama-amplifiers anikwe amandla ukude, yonke inethiwekhi kufanele isuswe amandla ukugwema amasekhethi amafushane. Nakuba i-voltage lapho ingekho phezulu kakhulu (60 V), yamanje ingumthombo wamandla ofanayo engikubonise kuwo inganikeza inani elikhulu: lapho indawo yokuhlala emaphakathi ithinta umzimba, isibonisi esikhulu seziqhumane siqinisekisiwe. Futhi uma ama-amplifiers anjalo engasindi ngaso sonke isikhathi ngempumelelo ekunqanyulweni kukagesi endlini, khona-ke ngale miphumela ekhethekile kukhona amathuba angewona ama-zero okukhubaza amanye amadivayisi amaningi, okuzodingeka aseshwe kuyo yonke indlu.
Kodwa futhi kwenzeka ukuthi i-amplifier iyaphila, kodwa ngesikhathi esifanayo idlulisa umsindo omkhulu kunethiwekhi, noma imane nje ingashwibi kuze kufike ezingeni lesiginali elidingwa umklamo (ngokuvamile i-110 dBµV). Lapha kufanele uqale uqinisekise ukuthi isignali ayifiki isivele yonakele ngokulinganisa isignali engenayo. Ezinye zezinkinga ezijwayelekile ezingelapheki zama-amplifiers zifaka okulandelayo:
- Thola ukuncishiswa. Ngenxa yokonakala kwengxenye noma sonke isigaba se-amplifier, sineleveli yesignali efanayo ekuphumeni njengalapho okokufakayo (noma ngaphezulu, kodwa akwanele ekusebenzeni okuvamile).
- Umsindo wesignali. Ukusebenza kwe-amplifier kuhlanekezela isignali kangangokuthi ipharamitha Yenkampani Yenethiwekhi/Umsindo (C/N) elinganiswa kokuphumayo ingaphandle kwesimiso futhi iphazamisa ukubonwa kwesignali ngabamukeli.
- Ukuhlakazwa kwengxenye yedijithali yesiginali. Kwenzeka ukuthi i-amplifier idlulisa isignali ye-analog ngendlela egculisayo, kodwa ngesikhathi esifanayo ayikwazi ukubhekana nesignali "yedijithali" nhlobo. Ngokuvamile, imingcele ye-MER ne-BER echazwe ku yeqa imingcele evumelekile futhi umlaza uphenduka udaka oluyisiphithiphithi, kodwa kwenzeka okuthile okuhlekisayo lapho, ngokwesibonelo, i-amplifier ikhohlwa enye yepharamitha yokuguquguquka futhi esikhundleni somlaza idweba indandatho noma indilinga esikrinini sedivayisi.
Uma lezi zinkinga zenzeka, i-amplifier kufanele ishintshwe, kodwa kunezinkinga ezingaqedwa ngokulungiswa. Ngokuvamile, isignali ekuphumeni kwe-amplifier intanta iye phansi futhi kwanele ukunciphisa inani le-attenuator yokokufaka. Futhi ngezinye izikhathi, ngokuphambene nalokho, i-amplifier iqala ukwenza umsindo ngenxa yezinga elikhulayo kokokufaka, bese siyicindezela phansi nge-attenuator. Zonke izinguquko kufanele zenziwe ku-amplifier eyodwa eyinkinga, ngoba uma, ngokwesibonelo, sinciphisa isignali ephuma kumamukeli optical, khona-ke lokhu kuzothinta ezinye, ukusebenza, ama-amplifiers futhi zonke kuzodingeka zihlelwe kabusha ngesandla kumapharamitha ashintshiwe. Futhi, ngenxa yokukhulisa kakhulu, isignali yedijithali ingase ihlukane (ngomsindo omncane ku-analogue). Ngichaze izilungiselelo ze-amplifier ngokuningiliziwe ku .
Ungazama ukulungisa ukutsheka ngezilungiselelo. Ngokuvamile, lapho uthumela inethiwekhi esanda kwakhiwa, i-slope enkulu yokuqala ayidingeki ukuze kuqinisekiswe imingcele emihle ekugcineni kwe-main. Kodwa ngokuhamba kwesikhathi, ngenxa yokuwohloka kwekhebula, kungase kudingeke ukuba kwandiswe umthambeka, okuthi, njengoba sikhumbula, ukwanda ngenxa yokuncipha kwezinga lama-frequencies aphansi, okuzodinga ukunxeshezelwa yi-attenuator.
Izamukeli ze-Optical ngokuvamile nazo ziyafa ngenxa nje yokunikezwa kwamandla. Uma inezinga lesignali elanele kokokufaka (engibhale kukho ), ngokuvamile azikho izinkinga ngokukhiphayo. Kwesinye isikhathi kwenzeka okufanayo - ukwanda komsindo nezinga lokuphuma elinganele, kodwa ngenxa yokuqina kwezilungiselelo, lokhu ngokuvamile akukwazi ukwelashwa. I-diagnostics iyafana - sihlola ukuthi ifudumele noma cha, bese silinganisa isignali kusuka kokuphumayo.
Ngokwehlukana, ngizothi ngezixhumi zokuhlola: akufanele uhlale uzithemba. Iqiniso liwukuthi noma ngabe yonke into ihlelekile, isignali ehliswe ngo-20-30 dB ingase ingabi nezinkinga ezifanayo nalokho okukhiphayo "kwangempela". Kodwa ngokuvamile kwenzeka ukuthi izinkinga endleleni zenzeka ngemva kompompi wokuhlola, bese konke kubonakala kuhamba kahle - kodwa empeleni kubi. Ngakho-ke, ukuze uqiniseke ngokuphelele, kuhlale kufanelekile ukuhlola indlela ephumayo ebheke emgwaqweni omkhulu.
Umgogodla we-Optical
Ungatshela okuningi ngezinkinga kanye nosesho lwazo kuma-optics, futhi kuhle ukuthi lokhu sekuvele kwenziwa ngaphambi kwami: . Ngizosho kafushane nje ukuthi uma sibona ukwehla kwesignali kumamukeli obonakalayo futhi akuhlobene nento enjengale:
Sine-cormorants e-St. Petersburg - uyazi ngokwakho. Futhi bayothola optics ngaphansi komhlaba.
khona-ke ukuhlanza noma ukufaka esikhundleni sentambo yokugcina yesichibi kungasiza. Ngezinye izikhathi kwenzeka ukuthi i-photodetector noma i-optical amplifier ilulaza; lapha, yiqiniso, imithi ayinawo amandla. Kodwa ngokuvamile, ngaphandle kwamathonya angaphandle ayingozi, i-optics inokwethenjelwa kakhulu futhi izinkinga nazo, njengomthetho, zehlela kugandaganda odla otshanini obuseduze.
Isiteshi esikhulu
Ngokungeziwe ezinkingeni ezisobala ngokunikezwa kwamandla kanye nokuxhumana nemithombo ngaphezu kwamanethiwekhi e-IP, enye yezinto eziyinhloko ekusebenzeni kwesihloko isimo sezulu. Umoya onamandla ungadabula kalula noma ujikelezise izimpondo, futhi iqhwa elimanzi elibambelele esitsheni sesathelayithi lenza libe mbi kakhulu izinga lokwamukela. Kunzima ukubhekana nalokhu, ngoba ama-antenna atholakala phezulu ngangokunokwenzeka, lapho isimo sezulu sinzima futhi ngisho nokushisa kwe-anti-icing kwezitsha akusizi ngaso sonke isikhathi, ngakho ngezinye izikhathi kufanele uzihlanze ngesandla.
PS Lokhu kuphetha uhambo lwami olufushane emhlabeni wethelevishini yekhebula. Ngethemba ukuthi lezi zihloko zisize ukwandisa ama-horizons akho futhi uthole okuthile okusha kokwaziyo. Kulabo okufanele basebenze nalokhu, ngincoma ukujulisa incwadi ethi "Cable Television Networks", umbhali S.V. Volkov, ISBN 5-93517-190-2. Ichaza yonke into oyidingayo ngolimi olufinyeleleka kakhulu.
Source: www.habr.com