Elona nqaku lokugqibela, elikruqulayo lereferensi. Mhlawumbi akukho sizathu sokuyifunda kuphuhliso jikelele, kodwa xa oku kusenzeka, kuya kukunceda kakhulu.
Iziqulatho zoluhlu lwamanqaku
Umrhumo wendawo
Ngoko ke, umabonakude kamakhulu wakho uyekile ukubonisa. Umthengele entsha, kodwa kwavela ukuba ingxaki ayikho kumamkeli - oku kuthetha ukuba kufuneka ujonge ngakumbi intambo. Okokuqala, zihlala zijikeleze izihlanganisi, ezingadingi ukukrazula, zijija ngokungummangaliso kwintambo, nto leyo ekhokelela ekuphulukaneni nonxibelelwano kunye ne-braid okanye i-core central. Nokuba isinxibelelanisi sisandul 'ukulungiswa kwakhona, kufuneka uqinisekise ukuba akukho nanye yeenwele eziphothiweyo eziqhagamshelwe kumqhubi ophakathi. Ngendlela, ububanzi be-core central ngokuqhelekileyo buqina ngakumbi kunomngxuma kwi-socket ye-receiver - oku kuyimfuneko kuqhagamshelwano olulungileyo ngenxa yokwandisa iipetali kwikhonkco. Nangona kunjalo, ukuba ngequbuliso utshintshe isinxibelelanisi ngesinye apho undoqo osembindini ungaphumi “njengoko unjalo”, kodwa ungena inaliti (njengaleyo iboniswe ndim izihlanganisi ze-RG-11), okanye utshintshe inxalenye yentambo kwaye entsha inesiseko esincinci, ngoko unokuhlangabezana nenyaniso yokuba iipetali ezidiniweyo kwi-socket aziyi kubonelela ngoqhagamshelwano oluhle kunye nombindi ophakathi.
Xa uthatha imilinganiselo ngesixhobo, konke oku kunokubonwa ngokulula ukusuka kwimilo yethambeka lophawu lophawu, endibhale ngalo . Ngale ndlela sinokubeka iliso ngokukhawuleza kwinqanaba lesignali (makhe ndikukhumbuze, ngokutsho kweGOST akufuneki ibe ngaphantsi kwe-50 dBµV yesiginali yedijithali kunye ne-60 yesiginali ye-analog) kwaye uvavanye ukuthomalalisa kwindawo ephantsi kunye nephezulu frequency, leyo. iza kusinika iingcebiso zophendlo oluqhubekayo lwengxaki.
Makhe ndikukhumbuze: ukuthotywa kwee-frequencies ezisezantsi kudla ngokunxulunyaniswa neengxaki kumbindi ophakathi, kwaye ukuthotywa okukhulu kwee-frequencies eziphezulu kubonisa uqhagamshelwano olubi kunye ne-braid, kwaye oku kudla ngokunxulunyaniswa ne-crimping (kakuhle, okanye imeko embi ngokubanzi ikhebula, kubandakanywa nobude obugqithisileyo).
Emva kokuphonononga intambo ngekhonkco kwiTV, kuyafaneleka ukuyilandelela kuyo yonke indawo yokuhlala: kuba intambo ye-coaxial ayisiyiyo umqhubi wombane kuphela, kodwa i-waveguide, ayixhomekanga kuphela kwikhefu kunye nolunye ukonakala komatshini, kodwa ikwagoba. kunye neekinks. Kukwafanelekile ukufumana zonke izahluli zesignali kunye nokubala ukuthotywa kwazo ngokupheleleyo: kunokuvela ukuba ngaphambi kokuba yonke into isebenze kumda kunye nokuthotywa okuncinci kwekhebula kukhokelele ekusebenzeni ngokupheleleyo. Kule meko, ukuze ungaphindi ulandele intambo efihliweyo emva kwe-trim, unokukhetha ngokufanelekileyo ukulinganiswa kwabahluli okanye ufake i-amplifier encinci emnyango wendlu.
Ukuba akukho nanye yale nto ibonwayo kwaye yonke into ihambelana nekhebula ukuya kwipaneli ephantsi-yangoku kwizitebhisi, ngoko kuyimfuneko ukulinganisa inqanaba lesignali elingena kwindlu. Ukuba inqanaba kunye nokuma kwesignali kwimpompo yesahluli somrhumo ziqhelekile, ngoko kuyafaneleka ukuvavanya umahluko phakathi kwamaxabiso kwiTV nakwiphaneli yokulawula kwaye ucinge malunga nokuba siphi kwaye yintoni esiyiphosileyo. Ukuba sibona ukuba ukuthotywa kweTV kwakunexabiso elithile, kodwa kwangaxeshanye sibona iingxaki ngomqondiso kwimpompo, ngoko kufuneka siqhubele phambili.
Umphakamisi
Emva kokubona ingxaki kwimpompo yomrhumo, kuya kufuneka uqiniseke ukuba umahluli ngokwawo akanatyala. Kwenzeka ukuba enye yeetephu ngokukhawuleza okanye ngokuthe ngcembe iyancipha iiparitha zesignali, ngakumbi kwizahluli kwinani elikhulu lababhalisi (ngaphezu kwe-4). Ukwenza oku, kufuneka ulinganise inqanaba lesignali kwenye impompo (ngokukhethekileyo ngokude kangangoko kunokwenzeka kwingxaki enye), kunye nakwikhebula eliphambili elingenayo. Apha kwakhona, ukuqonda ukuba yeyiphi imilo kunye nenqanaba umqondiso kufuneka ube luncedo. Ixabiso lokuthomalalisa kwitephu yomrhumi eliboniswe kwisahluli ekumakishweni (umzekelo, 412 - 4 iimpompo ze -12 dB nganye) kufuneka lithatyathwe koko bekulinganiswe kumgca oyintloko. Ngokufanelekileyo, kufuneka sifumane inani elithatyathwe kwimpompo yomrhumi. Ukuba iyahluka ngaphezu kwesibini se-dB, kungcono ukubuyisela isahluli esinjalo.
Ukuba sibona ukuba umqondiso sele ufikile ecaleni komgwaqo omkhulu kunye nethambeka eliqinileyo okanye inqanaba eliphantsi, ngoko kuya kufuneka siziqhelanise noyilo lwesiphaseli, okanye, sisebenzisa ingqiqo, siqikelele izinto ezimbini: ngaba isinyusi sakhiwe ngasentla okanye ngezantsi kwaye kude kangakanani kwisebe elikufutshane esikuyo. Eyokuqala inokuqondwa apho ikhebula eliqhagamshelwe kwigalelo lomhluli livela khona kwaye apho umntu ophuma kwisiphumo uya khona. Ngokuqhelekileyo akunzima ukulandelela iintambo eziphambili ngokuthe ngqo kwipaneli, kodwa ukuba zingabonakali, ngoko unokuya kumgangatho ongentla (okanye ngaphantsi) kwaye ubone ukuba yiyiphi ixabiso le-divider. Ukusuka Mhlawumbi uyakhumbula ukuba ihlelo kufuneka linciphe njengoko usiya phambili ukusuka ekuqaleni. Apho ndabhala kwakhona malunga nokwahlula ukunyuka kwiindawo (sivame ukubiza ngokuthi "pilasters", andiqinisekanga ukuba oku kwamkelwe ngokubanzi). Ngokuqhelekileyo, i-pilaster enye inabela ngaphezu kwe-5-6 imigangatho kwaye ekuqaleni kwayo kukho izahluli ezinomlinganiselo we-20-24 dB, kwaye ekugqibeleni - 8-10. Xa uqinisekile ukuba ingxaki ifumaneka ngaphandle komgangatho, kufuneka ufumane isiqalo se-pilaster kwaye uthathe imilinganiselo ukusuka kumhluli oyintloko apho iqala khona. Apha iingxaki zisafana: zombini isahluli ngokwaso kunye nekhebula eyonakalisiweyo kunye ne-crimping-quality-crimping ingaba nefuthe. Kwenzeka nokuba emva kokuhambisa izihlanganisi, umqondiso ubuyiselwa (kodwa ngokuphindaphindiweyo uphela ngokupheleleyo). Kule meko, kuya kufuneka uphinde unqande yonke into, kwaye kuya kuba kuhle ukuba abafakeli, bebonelele oku, bashiye unikezelo lwentambo. Emva kwayo yonke loo nto, xa i-crimping kwakhona kufuneka ifinyezwe. Kwintambo ye-RG-11, ingxaki ye-crimping engachanekanga ixhaphake kakhulu: oku mhlawumbi kukungaphumeleli ukuthobela umgangatho wokuhluba, apho umbindi ophakathi ushiywe ixesha elide (ngenxa yoko, isinxibelelanisi asihlaliswanga nkqi kwaye intambo inokutsiba kuyo), okanye into enye, kodwa ngenxa yecandelo A elikhulu kakhulu (jonga umfanekiso ongezantsi).
Kuyafaneleka ukukhankanya ngokwahlukileyo ukuba ukuhluthwa okufanelekileyo akuyi kukhusela kwiimpazamo ukuba i-crimper ayihlali ngokupheleleyo ikhonkco kwaye i-core central ayifaki "inaliti" yekhonkco. Ngelo xesha, inaliti inokuhamba ukuba uyayishukumisa ngomnwe wakho. Xa umthambo ungene kakuhle, akunakwenzeka ukuwuhambisa. Oku kufuneka kukhangelwe kwisidibanisi ngasinye esingaskriwanga.
Abahluli ngokwabo ezindlwini ezineminyaka engaphezu kwe-10 ubudala banokufumana into eyaziwayo phakathi kwabaqokeleli bemodeli "njengesibetho se-zinc."
Ifoto evela kwindawo
Izindlu ze-Divider ezenziwe ngee-alloys ezingaziwayo kwaye zibekwe kwiimeko ezimbi zemozulu zinokudilika ngokoqobo ezandleni zakho xa uzama ukukhulula isinxibelelanisi, okanye naxa iintambo zihamba kwikhaka. Kwaye ngokuqhelekileyo oku kwenzeka xa abafakeli besebenza kwiphaneli yokulawula, ukubonelela umntu nge-Intanethi, okanye abanye abaqhubi be-intercom.
Ukuba isahluli apho i-pilaster iqala khona ayikaphuki kwisiqingatha, kwaye inqanaba lesignali kulo libi njengakwindlu, ngoko kuyafaneleka ukufumana isahluli apho i-branching yokuqala yenzeke kunye nokulinganisa umqondiso oza kuthi. ukusuka kwizixhobo ezisebenzayo ukusuka kwisiseko (okanye i-attic - njengoko yakhiwe). Emva kokuba uphumelele isikhuphukeli ngale ndlela kwaye ungayisombululi ingxaki, kuya kufuneka uhambe ukhangele izixhobo ezisebenzayo kwaye uthathe imilinganiselo kuyo.
Izixhobo ezisebenzayo
Okokuqala, kuyafaneleka ukuba uqaphele ukuba phakathi kwabamkeli be-optical receivers kunye ne-amplifiers kukho kwakhona inethiwekhi yokusabalalisa, eyakhiwe ngokwemigaqo efana nokunyuka, kwaye ngoko ke ineengxaki ezifanayo. Ngoko ke, yonke into ebhaliweyo apha ngasentla kufuneka ihlolwe apha, kwaye emva koko ibekwe ityala ekusebenzeni kwe-hardware.
Ke, sikwigumbi elingaphantsi (i-attic, ibhodi yokutshintsha ephambili), phambi kwebhokisi eneamplifiers
Iyenzeka…
Ukuba akukho mqondiso ekuphakameni konke kwaye kukho ukukrokra ukuba i-amplifier ifile, ngoko ke indlela elula yokumisela ukuba yiyiphi iqondo lokushisa ukuya kwi-touch. Nakwiiqabaka eziqatha kumagumbi angatshisiyo, iamplifier esebenzayo iya kufudumala kunemeko engqongileyo, kwaye iamplifier etshisiweyo iya kunuka kubanda. Ukuba umahluko weqondo lokushisa awubonakali ngokwaneleyo, ngoko ukuyivula kuya kubonisa ukuba isalathisi samandla ngaphakathi kwe-amplifier ayikhanyi. I-amplifier enjalo ithathelwa indawo enye eyaziwayo ukuba iyasebenza, kwaye emva koko ilungiswe kusetyenziswa isikhululo sokuthengisa esiqhelekileyo, kuba phantse zonke iintsilelo zihambelana ne-banal swollen capacitors. Xa utshintsha ii-amplifiers ezisebenza kude, inethiwekhi yonke kufuneka ikhutshwe amandla ukuphepha iisekethe ezimfutshane. Nangona i-voltage ekhona ingekho phezulu kakhulu (60 V), ekhoyo ikwangamandla ombane endikubonise kuwo inokunika isixa esikhulu: xa indawo yokuhlala esembindini ichukumisa umzimba, isiboniso esikhulu somlilo siqinisekisiwe. Kwaye ukuba i-amplifiers ayisoloko isinda ngempumelelo ekucinyweni kombane endlwini, ke ngezi ziphumo zikhethekileyo kukho i-non-zero amathuba okukhubaza izixhobo ezininzi, eziya kuthi ke zikhangelwe kuyo yonke indlu.
Kodwa kuyenzeka ukuba iamplifier iyaphila, kodwa kwangaxeshanye ihambisa ingxolo eninzi kwinethiwekhi, okanye ngokulula ayijingi ukuya kwinqanaba lophawu olufunwa luyilo (ngokuqhelekileyo i-110 dBµV). Apha kufuneka uqale uqinisekise ukuba uphawu alufiki sele lonakaliswe ngokulinganisa umqondiso ongenayo. Ezinye zeengxaki eziqhelekileyo ezinganyangekiyo ze-amplifiers ziquka oku kulandelayo:
- Ukuzuza ukunciphisa. Ngenxa yokuthotywa kwenxalenye okanye sonke inqanaba le-amplifier, sinomgangatho wesignali ofanayo kwimveliso njengegalelo (okanye ngaphezulu, kodwa akwanelanga ukusebenza okuqhelekileyo).
- Ingxolo yomqondiso. Ukusebenza kwe-amplifier kuphazamisa umqondiso kangangokuthi i-Carrier / Noise (C / N) ipharamitha elinganiswe kwimveliso ingaphandle kwesiqhelo kwaye iphazamisa ukuqatshelwa komqondiso ngabamkeli.
- Ukusasazwa kwecandelo ledijithali lophawu. Kwenzeka ukuba i-amplifier idlulise umqondiso we-analog ngokwanelisayo, kodwa kwangaxeshanye ayikwazi ukujamelana nomqondiso "wedijithali" nonke. Amaxesha amaninzi, i-MER kunye ne-BER iiparamitha ezichazwe kuyo hamba ngaphaya kwemida evumelekileyo kwaye iqela leenkwenkwezi lijika libe yingxubakaxaka yesiphithiphithi, kodwa kwenzeka into ehlekisayo xa, umzekelo, iamplifier ilibale ngenye yeeparamitha zokumodareyitha kwaye endaweni yekroza izoba ikhonkco okanye isangqa kwiscreen sesixhobo.
Ukuba ezi zinto zingasebenzi kakuhle, i-amplifier kufuneka itshintshwe, kodwa kukho iingxaki ezinokuthi zipheliswe ngohlengahlengiso. Ngokuqhelekileyo, isignali kwimveliso ye-amplifier idada ezantsi kwaye yanele ukunciphisa ixabiso le-input attenuator. Kwaye ngamanye amaxesha, ngokuchaseneyo, i-amplifier iqala ukwenza ingxolo ngenxa yezinga elongezelelweyo kwigalelo, ngoko siyicinezela phantsi nge-attenuator. Zonke izilungiso kufuneka zenziwe kwi-amplifier enye eyingxaki, kuba ukuba, ngokomzekelo, sinciphisa isignali ephuma kwi-receiver optical, ngoko oku kuya kuchaphazela ezinye, ukusebenza, i-amplifiers kwaye zonke ziya kufuneka zilungiswe ngesandla kwiiparameters ezitshintshileyo. Kwakhona, ngenxa yokwandisa kakhulu, isignali yedijithali ingahlukana (ngengxolo encinci kwi-analogue). Ndichaze izicwangciso zeamplifier ngokweenkcukacha kwi .
Ungazama ukulungisa i-tilt kunye nezicwangciso. Ngokuqhelekileyo, xa ugunyazisa inethiwekhi esanda kwakhiwa, i-slope enkulu yokuqala ayifuni ukuqinisekisa iiparameters ezilungileyo ekupheleni kweyona nto iphambili. Kodwa ngokuhamba kwexesha, ngenxa yokuthotywa kwekhebula, kunokufuneka ukuba kwandiswe i-slope, leyo, njengoko sikhumbula, inyuka ngenxa yokuncipha kwinqanaba lee-frequencies eziphantsi, okuya kufuneka kuhlawulwe yi-attenuator.
Abamkeli be-Optical badla ngokufa ngenxa yobonelelo lwamandla. Ukuba inomgangatho wesignali owaneleyo kwigalelo (into endiyibhale kuyo ), ngoko akukho ngxaki ngemveliso. Ngamanye amaxesha kwenzeka into efanayo - ukunyuka kwengxolo kunye nenqanaba lokungaphumeleli kwemveliso, kodwa ngenxa yokunyanzeliswa kwezicwangciso, oku ngokuqhelekileyo akunakunyangwa. Ukuxilongwa kuyafana - sijonga ukuba kushushu okanye akunjalo, kwaye emva koko silinganisa umqondiso ovela kwimveliso.
Ngokwahlukileyo, ndiza kuthetha malunga nezixhumi zovavanyo: akufanele uhlale ubathemba. Inyaniso kukuba nangona yonke into ilungile, isignali ethotywe ngo-20-30 dB ayinakuba neengxaki ezifanayo ukuba imveliso "yokwenene" inakho. Kodwa kaninzi kwenzeka ukuba iingxaki endleleni zenzeka emva kwempompo yovavanyo, kwaye emva koko yonke into ibonakala ilungile - kodwa ngokwenene iyoyikeka. Ke ngoko, ukuze uqiniseke ngokupheleleyo, kusoloko kufanelekile ukujonga kanye indlela yokuphuma ejongene nohola wendlela.
Umqolo obonakalayo
Unokuxelela okuninzi malunga neengxaki kunye nokukhangela kwabo kwi-optics, kwaye kulungile ukuba oku sele kwenziwe phambi kwam: . Ndizakuthi ngokufutshane ukuba sibona umqondiso wehla kwi-receiver optical kwaye ayihambelani nento enje:
Sine-cormorants eSt. Petersburg - uyazi ngokwakho. Kwaye baya kufumana i-optics phantsi komhlaba.
emva koko ukucoca okanye ukutshintsha intambo yokugqibela ye-patch kunokunceda. Ngamanye amaxesha kwenzeka ukuba i-photodetector okanye i-amplifier optical ithobe, apha, ngokuqinisekileyo, iyeza alinamandla. Kodwa ngokubanzi, ngaphandle kweempembelelo zangaphandle eziyingozi, i-optics ithembeke kakhulu kwaye iingxaki kunye nabo, njengomthetho, zehla kwitrektara edla ingca ekufutshane.
Isikhululo esikhulu
Ukongeza kwiingxaki ezicacileyo kunye nokunikezelwa kwamandla kunye nokudibanisa kunye nemithombo phezu kwamanethiwekhi e-IP, enye yezinto eziphambili ekusebenzeni kwentloko yimozulu. Umoya onamandla unokukrazula okanye ujikeleze ngokulula i-eriyali, kwaye ikhephu elimanzi libambelele kwisitya sesathelayithi liwenza mandundu kakhulu umgangatho wokwamkela. Kunzima ukujongana nale nto, kuba ii-antenna zibekwe phezulu kangangoko kunokwenzeka, apho imozulu inzima kwaye ukufudumeza kwe-icing izitya akusoloko kunceda, ngoko ngamanye amaxesha kufuneka uhlambulule ngesandla.
PS Oku kuqukumbela uhambo lwam olufutshane kwilizwe lomabonakude wentambo. Ndiyathemba ukuba la manqaku akuncedile ukwandisa i-horizons yakho kwaye ufumane into entsha kwinto eqhelekileyo. Kwabo kufuneka basebenze nale nto, ndincoma ukujula incwadi ethi "Cable Television Networks", umbhali S.V. Volkov, ISBN 5-93517-190-2. Ichaza yonke into oyifunayo ngolwimi olufikeleleka kakhulu.
umthombo: www.habr.com