Kweli nqaku siza kujonga i-high-frequency radio signal amplifiers ye-cable television kwi-coaxial part of the line.
Iziqulatho zoluhlu lwamanqaku
- Icandelo 6: I-RF Signal Amplifiers
- Icandelo 7: Abamkeli bamehlo
- Icandelo 8: Inethiwekhi ye-Optical backbone
- Icandelo 9: Intloko
- Icandelo 10: Ukulungisa inethiwekhi yeCATV
Ukuba kukho enye kuphela i-optical receiver endlwini (okanye nakwibhloko yonke) kwaye zonke iintambo zokunyuka zenziwe nge-coaxial cable, ukukhulisa umqondiso kuyadingeka ekuqaleni kwabo. Kwinethiwekhi yethu, sisebenzisa kakhulu izixhobo ezivela kwi-Teleste, ngoko ke ndiya kukuxelela usebenzisa umzekelo wabo, kodwa ngokusisiseko, izixhobo ezivela kwabanye abavelisi azifani kwaye isethi yokusebenza yoqwalaselo idla ngokufana.
Imodeli yeCXE180M inenani elincinci leseto:
Njengoko mhlawumbi ukhumbula kumacandelo angaphambili, isignali ineeparamitha ezimbini ezibalulekileyo zobungakanani: inqanaba kunye nethambeka. Ngabo abanokunceda ukulungisa izicwangciso zeamplifier. Masiqale ngokulandelelana: ngokukhawuleza emva kokudibanisa igalelo kukho isithomalalisi. Ikuvumela ukuba unciphise isignali yegalelo ukuya kwi-31 dB (xa i-jumper eluhlaza okwesibhakabhaka iguqulwa ngokuhambelana nomzobo, uluhlu lwe-knob lutshintsha ukusuka kwi-0-15 ukuya kwi-16-31 dB). Oku kunokuba yimfuneko ukuba i-amplifier ifumana umqondiso ongaphezulu kwe-70 dBΒ΅V. Inyani kukuba inqanaba le-amplifier libonelela ngokunyuka kwinqanaba lophawu nge-40 dB, kwaye kwimveliso kufuneka sisuse ngaphezulu kwe-110 dBΒ΅V (kwinqanaba eliphezulu umlinganiso wesandi ukuya kwingxolo wehla kakhulu kwaye eli nani lifanelekile zonke izandisi zebroadband kunye nabamkeli abane-amplifier eyakhelwe-ngaphakathi) . Ngoko ke, ukuba i-80 dBΒ΅V ifikelela kwigalelo leamplifier, umzekelo, ngoko kwimveliso iyakusinika i-120 dBΒ΅V yengxolo kunye namanani asasaziweyo. Ukunqanda oku, kufuneka usete i-attenuator yegalelo kwindawo yokudambisa i-10 dB.
Emva kwe-attenuator sibona isilinganisi. Kuyimfuneko ukuphelisa ukuthambeka okubuyela umva, ukuba kukho. Oku kufezekiswa ngokunciphisa inqanaba lesignali kwindawo ephantsi yefrikhwensi ukuya kuthi ga kwi-20 dB. Kuyaphawuleka ukuba asiyi kukwazi ukuphelisa i-slope ejikelezayo ngokuphakamisa inqanaba lee-frequencies eziphezulu, kuphela ukucinezela asezantsi.
Ezi zixhobo zimbini zihlala zanele ukulungisa ukunxaxha komqondiso omncinci ukusuka kwisiqhelo. Ukuba oku akunjalo, ungasebenzisa oku kulandelayo:
Isifanisi sekhebula, eyenziwe ngendlela yokufakela enokuthi ibekwe ngokuthe tye okanye ngokuthe nkqo, njengoko igama lithetha, lilinganisa ukufakwa kwecandelo elide lekhebula, apho ukuthotywa kwe-frequencies ephezulu yoluhlu kufuneka kwenzeke. Oku kukuvumela ukuba unciphise i-slope ngokuthe ngqo ukuba kuyimfuneko, ukucinezela i-8 dB kwindawo ephakamileyo. Oku kunokuba luncedo xa ufaka i-amplifiers kwi-cascade kumgama omfutshane, umzekelo.
Emva koku kuguqulwa, umqondiso udlula kwinqanaba lokuqala le-amplifier, emva koko sibona enye i-insert, evumela ukuba sinciphise ngakumbi inzuzo. I-jumper elandelayo iya kuphinda isincede sicinezele amaza asezantsi ukuze sifumane ithambeka elifunekayo. Ezi seto zimbini ziyafana ngokusisiseko kunye ne-attenuator yokufaka kunye ne-equalizer, kodwa isebenza kunye nenqanaba lesibini le-cascade.
Kwisiphumo senqanaba le-amplifier sibona impompo yovavanyo. Esi sisidibanisi esinemisonto esisemgangathweni onokuqhagamshela kuso isixhobo sokulinganisa okanye umamkeli kamabonakude ukujonga umgangatho wophawu lwemveliso. Ayizizo zonke izixhobo kwaye phantse akukho TV ezikwaziyo ukusetyenzwa ngokufanelekileyo umqondiso kunye nenqanaba lekhulu okanye ngaphezulu kwe-dBΒ΅V, ngoko ke iinkokeli zovavanyo kuzo naziphi na izixhobo zihlala zenziwe nge-attenuation ye-20-30 dB ukusuka kweyona xabiso lemveliso. Oku kufuneka kuhlale kukhunjulwe xa uthatha imilinganiselo.
Olunye ufakelo lufakwe phambi kokuphuma. Ifoto yeamplifier ibonisa ukuba utolo oluboniswe kuyo lukhomba kuphela kwi-terminal efanelekileyo. Kwaye oku kuthetha ukuba akuyi kubakho mqondiso ngasekhohlo. Ukufakwa okunjalo kufakwe kwezi amplifiers "ngaphandle kwebhokisi", kwaye ngaphakathi kwebhokisi ngokwayo kukho enye ifakwe kwisethi yokuhanjiswa:
Ikuvumela ukuba usebenzise imveliso yesibini, kodwa ngokuqinisekileyo yazisa ukuncipha komqondiso we-4 dB.
Ukuqala nje, imodeli yeamplifier CXE180RF inesetingi eziphindwe kabini:
Enyanisweni, yonke into ayisoyikeki kakhulu: ngaphandle kweeyantlukwano ezincinci, yonke into apha iyafana nale ixutyushwa ngasentla.
Okokuqala, itephu yovavanyo yavela kwigalelo. Kuyadingeka ukulawula umqondiso ngaphandle kokuqhawula intambo kwigalelo le-amplifier kwaye, ngokufanelekileyo, ngaphandle kokuphazamisa ukusasazwa.
Okwesibini, izihluzi ezintsha ze-diplex, kunye ne-attenuator ephumayo kunye ne-equalizer, ziyimfuneko ukuseta amajelo osasazo e-DOCSIS, ke ngeenjongo zeli nqaku ndiza kuthetha kuphela ukuba izihluzi zinqumle ezo frikhwensi zibonisiwe kuzo kwaye oku kunokwenza. ibeyingxaki ukuba kumajelo osasazo kamabonakude asasazwa kula maza. Ngethamsanqa, umenzi uzivelisa ngamaxabiso ahlukeneyo kwaye ukubuyisela endaweni yazo ukuba kuyimfuneko akunzima.
Amaqhina (kunye ne-jumper, eyazisa ukuthotywa kwe-10 dB) ichaphazela ngokukodwa umjelo wokubuyisela kwaye ayinakho indlela yokutshintsha isignali kamabonwakude.
Kodwa iijumpi ezintathu eziseleyo zisinika ukuba siqhelane nobuchwephesha obunje amandla akude.
Xa kuyilwa izindlu, ii-amplifiers zihlala zibekwe kwiindawo apho kunokubakho iingxaki malunga nokunikezelwa kombane kwiibhodi zokuhambisa. Ukongezelela, iplagi nganye yeplagi-socket pair, ekwabandakanya i-breaker circuit (enokuthi ifakwe kwindawo engalindelekanga), imele indawo enokuthi ingaphumeleli. Kule nkalo, kunokwenzeka ukwenza izixhobo zombane ngokuthe ngqo nge-coaxial cable. Ngaphezu koko, njengoko kunokubonwa kwiimpawu kwipleyiti yobonelelo lwamandla, inokuba yinto etshintshanayo okanye ethe ngqo ngokunoluhlu olubanzi kakhulu lwamandla ombane. Ke: ezi jumpers zintathu zenza ukuba kubekho unikezelo lwangoku oluqukuqelayo kwigalelo, kunye nakwisiphumo ngasinye sesibini ngokwahlukeneyo, ukuba sifuna ukunika amandla iamplifier elandelayo kwi-cascade. Xa ukunyuka kunye nababhalisi kuvuliwe, i-voltage ayikwazi ukunikezelwa kwimveliso, kunjalo!
Senditshilo kwi Inxalenye ethi kwinkqubo enjalo kusetyenziswa iimpompo ezingundoqo ezikhethekileyo:
Basebenzisa izinto ezinkulu kunye nezithembekileyo, kwaye umzimba omkhulu unikezela ukutshatyalaliswa kobushushu kunye nokukhusela.
Umthombo wamandla kulo mzekelo yibhloko ene-transformer eyakhelwe-ngaphakathi enkulu:
Kuyafaneleka ukuthetha ukuba, ngaphandle kokubonakala kweyona ndlela ilungileyo yeskimu sonikezelo lwamandla okude, ii-amplifiers ezisebenza ngolu hlobo azinakwenzeka ukuba ziphile ukusilela kombane ekhaya ngaphandle kweziphumo, kwaye xa zitshintshwa, abasebenzi bobuchwephesha nabo kufuneka bajonge kwaye bacime. amandla kwiyunithi ngokwayo, ukuze ungasebenzi kunye neentambo eziphilayo kwaye, ngoko, Xa i-amplifier enye ithathelwe indawo, yonke indlu ihleli ngaphandle komqondiso. Ngesizathu esifanayo, i-amplifiers ifuna impompo yovavanyo kwigalelo: kungenjalo kuya kufuneka usebenze ngentambo ephilayo.
Kuya kuba lunomdla ukwazi ukusuka koogxa ukuba iinkqubo eziqhelekileyo kunye nokunikezelwa kwamandla okude, bhala kwizimvo ukuba uyazisebenzisa, nceda.
Ukuba ufuna ukudibanisa inani elikhulu leTV ngaphakathi kwindlu okanye iofisi, unokuhlangabezana nokungabikho kwinqanaba emva kwekhonkco labahluli. Kule meko, kuyimfuneko ukufaka i-amplifier kwindawo yombhalisi, apho kusetyenziswa izixhobo ezincinci ezinenani elincinci lezicwangciso kunye nenqanaba eliphantsi lokukhulisa.
Umzekelo, njengale:
umthombo: www.habr.com