Khasong ea FM, boleng ba molumo bo bohlokoa. Batho ba lula ba loanela ho nts'etsapele theknoloji e ncha ho fokotsa matšoao a lerata phetisong ho ntlafatsa matshwao a mamelwang le boiphihlelo ba ho mamela. Tse peli tsa mahlale ke Khatello ea Pele le Khatello. Na ua li utloisisa? Kabelo ena e tla hlahisa tlhaloso le ts'ebeliso ea Khatello ea Pele le Khatello ho uena.
Ho arolelana ke Ho tsotella!
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Khatiso ke Eng?
Haele hantle, Khatello ea Pele le Khatello e ka bitsoa khatiso hammoho. Empa ke hobane'ng ha e arotsoe ka Pre-emphasis le De-emphasis? Ho araba potso ena, re hloka ho ba le kutloisiso ea mantlha ea Khatello ea Pele le Khatello.
Tlhaloso ea Khatiso ea Pele
Khatello ea pele ke mohopolo o sebelisoang ho fetisa lisebelisoa tse kang li-transmitters tsa FM. Ho bolela hore pele ho ts'ebetso e itseng, joalo ka ha matšoao a hajoale a fetisoa ka cable, mofuta o itseng oa maqhubu a ho kenya o tla matlafatsoa kapa amplitude e atolosoe. Ka mantsoe a bonolo, molumo oa molumo ka har'a mefuta e itseng o phahamisitsoe.
Tlhaloso ea Ho Hatisa
Ho e-na le hoo, De-ephasis ke mohopolo o sebelisoang ho amohela lisebelisoa tse kang liea-le-moea tsa FM. Ho bolela hore pele mats'oao a molumo a fetoloa molumo 'me a bapaloa, lebelo le ts'oanang la maqhubu le tla sebetsa phetoho e fapaneng le Khatello ea Pele. Seo se bolela hore molumo oa molumo sebakeng se itseng o tla fokotseha.
Liphapang tsa Khatello ea Pele le Khatello
Qetellong, Khatello ea Pele le Khatello ea Khatiso li tšoana, empa li sebelisoa lisebelisoa tse fapaneng le ho sebetsa ka tsela e fapaneng. Empa ba sebetsa ka sepheo se le seng - ho ntlafatsa matshwao a medumo.
Khatiso e Sebetsa Joang?
Khatello ea pele le Khatello ea maikutlo li sebetsa 'moho ho ntlafatsa matshwao a medumo. Empa ba finyella morero oo joang?
Lerata la Lipontšo tsa Audio
Matshwao a maqhubu a batlang a phahame a na le matla a ho hanyetsa matshwao a hodimo, empa a na le matla a ho sitisa lerata le ho feta hobane matshwao a maqhubu a batlang a phahame a na le matla a manyane ho feta a maqhubu a tlase haholo. Kahoo khaso ea seea-le-moea, ho tlosa lerato la lerata ka maqhubu a phahameng ke habohlokoa. 'Me Khatello ea Pele le Ho hatisa ho rarolla bothata ka ho ntlafatsa SNR ea matšoao.
Pheliso ea Lerata
Ha re boneng hore na Pre-emphasis le De-emphasis li sebetsa 'moho joang ho ntlafatsa SNR ea matšoao.
Etsa qeto ea Maqhubu - Ho hatisoa pele ho matlafatsa likarolo tse phahameng tsa maqhubu ka potoloho e bonolo ea ho hatisa pele. Potso ke ena, mokhoa oa ho tseba hore na ke mofuta ofe oa maqhubu o lokelang ho holisoa? U tla bona ho na le nako ea nako pele matšoao a ntlafatsoa. Re bitsa sekhahla sa nako nako e sa fetoheng. E baloa ka mokhoa oa T = RC, moo R e emelang ho hanyetsa potolohong 'me C e emetse phepelo ea matla potolohong. Ka tloaelo, 25μs, 50μs, le 75μs li-constants tsena tsa linako tse tharo lia fumaneha, 'me linaha tse fapaneng li nka linako tse fapaneng tsa nako e le maemo. Ka mohlala, Amerika Leboea le Korea Boroa, 75μs e sebelisoa, 'me Europe, 50μs e sebelisoa.
Matlafatsa Maqhubu - Haeba 75μs e sebelisoa e le nako e sa fetoheng, potoloho ea pele ho khatiso e tla ntlafatsa maqhubu a phahameng ho feta 2123 Hz ka sekhahla sa 6 dB/octave, le 6 dB e bolela makhetlo a mane. Kamora ho ntlafatsa maqhubu, SNR e ne e tla ntlafatsoa hobane karolo e holisitsoeng ea maqhubu e tla fokotsa lerata ho matšoao.
Khutlisetsa Maqhubu - E le hore ho be le karabelo e tloaelehileng ea maqhubu, seteraeke sa De-emphasis se lokela ho eketsoa moamoheli oa seea-le-moea. Feela joalokaha e tšoana le potoloho ea Pre-emphasis, e na le nako ea nako ka mor'a ho amohela maqhubu a seea-le-moea, 'me e tšoana le ea potoloho ea Pre-emphasis. Mohlala, 75μs e sebelisoa ho De-emphasis, ebe e tla fokotsa maqhubu a phahameng ho feta 2123Hz ka sekhahla sa 6dB/octave.
Lisebelisoa tsa Khatiso
Khasong ea seea-le-moea, Khatiso ea Pele le Khatello e amoheloa lits'ebetsong tse ngata, joalo ka khaso ea FM. Hobane FM e na le tšobotsi ea maqhubu a phahameng, ho bonolo ho angoa ke lerata. Ho hatisoa pele le ho hatisa ho ka ntlafatsa SNR ka lipontšo ka katleho. Ntle le phetiso ea lets'oao la analog, phetisetso ea dijithale le eona e amohela Khatello. Ho tšoana le phetisetso ea analog, phetisetso ea dijithale e sebelisitse Khatiso bakeng sa ho lokisa ho khopama ha ho fetisa matšoao ka litefiso tse phahameng tsa data.
Lipotso Asked hangata
1. P: Khatello ea FM ke Efe?
A: Ke mokhoa oo lets'oao le fetoloang ka tsela e itseng 'me la khutlela ho tloaelehileng qetellong.
Ts'ebetsong ea ho rekota le ho hasa, molemong oa ho ntlafatsa boleng ba lets'oao, ho totobatsoa ke hore lets'oao le fetotsoe ka tsela e itseng pele ho rekota kapa ho fetisoa, le ts'ebetso e latelang pheletsong e 'ngoe e khutlisetsang lets'oao maemong a lona a tloaelehileng. Mohlala o tloaelehileng haholo oa ho rekota molumo ke ho fokotsa lerata.
2. P: Hobaneng Khatello ea Pele e Sebelisa ho Transmitter ea FM?
A: Hobane e sebelisetsoa ho ntlafatsa SNR le ho fokotsa lerato la lerata.
Nakong ea ho lemoha lets'oao le fetotsoeng khafetsa, moamoheli o ne a tla hlahisa molumo oa lerata o nyolohang khafetsa. Khatello ea pele e eketsa boholo ba maqhubu a mats'oao a holimo, ka hona e ntlafatsa SNR le ho fokotsa lerato la lerata. The li-transmitters tsa FM tse rekisoang ka ho fetisisa ho tsoa ho FMUSER ba na le theknoloji ea morao-rao ea khatiso, haeba u e thahasella, e hlahlobe.
3. P: Matshwao a FM ke eng?
A: Ke matšoao a kenyelletsang tlhahisoleseling ka ho fetola maqhubu a hang-hang a leqhubu.
Lipontšo tsa FM li sebelisoa haholo likhomphutha, likhokahano tsa mehala le ts'ebetso ea matšoao. Ba jere boitsebiso ka mokhoa oa liphetoho tse etsahalang hanghang tsa leqhubu.
4. P: Lethathamo la matshwao a FM ke lefe?
A: 87.5 -108.0 MHz, 76.0 - 95.0 MHz, 65.8 - 74.0 MHz.
87.5 - 108.0 MHz ke lebelo le sebelisoang ka ho fetisisa lefatšeng ka bophara. 'Me 76.0 - 95.0 MHz e sebelisoa Japane, 65.8 - 74.0 MHz e sebelisoa haholo-holo linaheng tse ka bophirimela ho Europe.
fihlela qeto e
Ha re bua ka taba ena, rea tseba hore Khatiso ke thekenoloji e sebetsang hakaale ea khaso ea seea-le-moea, e ntlafatsa ka nepo mats'oao a seea-le-moeeng phetisong. FMUSER ke morekisi ea hloahloa oa lisebelisoa tsa seea-le-moea, o ka reka liphatlalatso tsa boleng bo holimo tsa FM ka litheko tse khotsofatsang. Haeba o hloka ho reka liphatlalatso tsa seea-le-moea sa FM ka ho hatisa pele, ka kopo ikutloe u lokolohile ho ikopanye le FMUSER.
Hape Bala
