Izimiso Eziyisisekelo Zokukhiqizwa Komsakazo We-FM
Kusukela ekusungulweni kwayo ekuqaleni kwekhulu lama-20, umsakazo ube ngomunye wemidiya yokuxhumana enethonya kakhulu futhi esebenza kahle emhlabeni. Ngokuthuthuka kwezobuchwepheshe, ukusakazwa komsakazo we-FM (Frequency Modulation) sekuyindlela ekhethwayo ngoba kunikeza ikhwalithi yomsindo engcono kune-AM (Amplitude Modulation). Lesi sihloko sizochaza izimiso eziyisisekelo zokwakhiwa komsakazo we-FM, kusukela emqondweni oyisisekelo wokuguqulwa kwemvamisa kuya endleleni izingxenye ohlelweni lomsakazo we-FM ezisebenza ngayo.
1. Umlando Omfushane kanye Nemibono Eyisisekelo
Umsakazo we-FM waqala ukwakhiwa ngu-Edwin Howard Armstrong ngo-1933. Waphefumulelwa ukuxazulula izinkinga eziyinhloko ezibhekene nomsakazo we-AM, okungukuthi ukuphazamiseka nomsindo ongaguquki. I-FM, noma i-Frequency Modulation, inikeza ikhambi ngokudlulisa izimpawu zomsindo ngokushintsha imvamisa yegagasi lomthwali, kunokuba kube yi-amplitude njengaku-AM.
Ngokuyisisekelo, isignali yomsindo noma isignali yolwazi iguqulwa ibe ukushintshashintsha kwemvamisa yegagasi lokuthwala elinobukhulu obungaguquki. Lokhu kushintshashintsha kwemvamisa kwaziwa ngokuthi ukuguqulwa kwemvamisa. Le ndlela yenza amasignali e-FM amelane kakhulu nokuphazamiseka futhi inikeza ikhwalithi yomsindo ecacile nenemininingwane eminingi.
2. Izingxenye Eziyinhloko Zohlelo Lomsakazo We-FM
Umsakazo we-FM uqukethe izingxenye eziningana eziyinhloko ezisebenza ngokubambisana ukwamukela, ukuguqula, nokunciphisa izimpawu. Okulandelayo yizingxenye ezibalulekile zesistimu yomsakazo we-FM:
a. I-Antenna
I-antenna iyisici esibalulekile esibhekene nokubamba amaza omsakazo akhishwa esiteshini sokudlulisa. Emsakazweni we-FM, ama-antenna ngokuvamile aklanyelwe ukuphatha amaza omsakazo anamaza omsakazo angaba ngu-88 kuya ku-108 MHz.
b. Umshuni
Umsebenzi we-tuner ukukhetha imvamisa ethile kuzo zonke izimpawu zomsakazo ezitholwa yi-antenna. Emisakazweni yesimanje ye-FM, i-tuner ivame ukusebenzisa ubuchwepheshe be-PLL (Phase-Locked Loop), obuvumela ukulungiswa okunembile kwemvamisa etholwayo.
c. I-Oscillator
I-oscillator emsakazweni we-FM isetshenziselwa ukukhiqiza isignali yemvamisa engaguquki ezongezwa esignalini ethathwe yi-tuner ukuze kube lula inqubo yokususa umsindo.
d. Ama-Amplifier Emvamisa Ephakathi (IF)
Ngemva kokuba isignali isibanjiwe futhi icutshungulwe yi-oscillator, ikhuliswa yi-amplifier yemvamisa ephakathi. Lesi yisigaba lapho isignali ikhuliswa khona ukuze isilungiselele isigaba esilandelayo sokucubungula.
e. I-Modulator kanye ne-Demodulator
I-FM modulator iyithuluzi eliguqula isignali yomsindo ibe ukushintshashintsha kwemvamisa yamagagasi othwala, okuvumela ukuthi idluliselwe. Ngokuphambene nalokho, i-demodulator ikhipha isignali yomsindo ekushintsheni kwemvamisa yamagagasi othwala ngesikhathi sokwamukela.
f. Isikhulisi Somsindo
Ngemva kokuba isignali yomsindo isisusiwe, kusadingeka ikhuliswe ngaphambi kokuba ithunyelwe kusipika. I-amplifier yomsindo ikhulisa ubukhulu besignali yomsindo ukuze izwakale ngevolumu eyanele.
g. Isikhulumi
Ingxenye yokugcina yisikhulumi esiguqula izimpawu zikagesi zibe amaza omsindo angazwiwa ngabantu.
3. Inqubo Yokusebenza Yomsakazo We-FM
Ake sixoxe kabanzi ngokuthi ngayinye yalezi zingxenye isebenza kanjani ngokulandelana ohlelweni lomsakazo we-FM.
a. Ukwamukelwa Kwesignali
Le nqubo iqala lapho i-antenna ithatha amaza omsakazo akhishwa ku-FM transmitter. Lawa maza omsakazo ayi-electromagnetic oscillations ngemvamisa ethile (88–108 MHz).
b. Ukukhethwa Kwemvamisa
Isignali ethathwe yi-antenna idluliselwa ku-tuner, bese ikhetha imvamisa oyifunayo. Isignali yomsakazo ephumayo itholakala ku-frequency elungisiwe, bese idluliselwa ku-oscillator ukuze icutshungulwe kabanzi.
c. Ukwakheka Kwemvamisa Ephakathi
I-oscillator emsakazweni we-FM ixuba isignali etholakele ngemvamisa ethile ukuze ikhiqize isignali yemvamisa ephakathi (IF). Ngokuvamile, lesi signali se-IF singemvamisa ecutshungulwa kalula, njenge-10.7 MHz.
d. Ukuqinisa Nokuthola
Ngemva kokuthola isignali ye-IF, ikhuliswa nge-amplifier yemvamisa ephakathi ngaphambi kokungena kwi-demodulator. I-demodulator ikhipha isignali yomsindo esignalini ye-IF. Kulokhu kususwa, izinguquko emvamisa yesignali ye-IF zihunyushwa zibuyiselwe esignalini yomsindo yokuqala.
e. Ukukhulisa Isignali Yomsindo
Ngemva kokuba isignali yomsindo ikhishwe esignalini ye-IF, isuke isebuthakathaka kakhulu ukuba izwakale ngqo kusuka kusipika. Ngakho-ke, isignali yomsindo idluliselwa ku-amplifier yomsindo ukuze ikhuliswe.
f. Umsindo Ophumayo
Ekugcineni, isignali yomsindo ekhulisiwe ithunyelwa esipikheni, esiguqula isignali kagesi ibe amaza omsindo indlebe yomuntu engawezwa.
4. Izinzuzo kanye Nezinselele Zomsakazo We-FM
Izinzuzo:
– Ikhwalithi Yomsindo Engcono: Ngenxa yendlela yokushintsha imvamisa, umsakazo we-FM umelana kakhulu nokuphazanyiswa nomsindo uma kuqhathaniswa nomsakazo we-AM.
– I-Bandwidth Ebanzi: Umsakazo we-FM une-bandwidth enkulu kune-AM evumela ukudluliswa kwe-stereo futhi inikeza ulwazi olucebile lokulalela.
– Ukuphazamiseka Okuncishisiwe: Imvamisa ephezulu yomsakazo we-FM ayithinteki kalula ekuphazamisekeni okuvela kumadivayisi kagesi azungezile kanye nomsindo womoya.
Inselele:
– Ukusabalala Okulinganiselwe: Amaza aphezulu e-FM anebanga lokusakaza elifushane uma kuqhathaniswa ne-AM futhi athintwa kakhulu yizithiyo zomzimba ezifana nezakhiwo nezintaba.
– Ingqalasizinda Ebiza Kakhulu: Idinga ingqalasizinda eyengeziwe ngenxa yokungafinyeleleki kwayo okulinganiselwe, ikakhulukazi ezindaweni ezinkulu nezingalingani.
5. Ukusungula Izinto Ezintsha kanye Nekusasa Lomsakazo We-FM
Njengoba ushintsho lwedijithali lushesha emhlabeni wonke, umsakazo we-FM nawo usushintshile. Ubuchwepheshe obufana nomsakazo wedijithali (i-DAB) kanye nomsakazo we-hybrid manje sebuhlanganiswa nokusakazwa kwe-FM ukuze kunikezwe okuqukethwe okwengeziwe, njenge-metadata yezingoma, ulwazi lwesimo sezulu, kanye nezinye izinsizakalo.
Ngaphezu kwalokho, ukusakaza ngedijithali kunikeza ikhono lokuhlanganisa izinzuzo zomsakazo we-FM nezinzuzo zedijithali njengekhwalithi yomsindo engcono kanye nezinsizakalo ezisebenzisanayo. Ukusungula izinto kuyaqhubeka, futhi ikusasa lomsakazo we-FM liqhakazile ngokuhlanganiswa kobuchwepheshe obusha.
Isiphetho
Umsakazo we-FM uthuthuke kakhulu kusukela wasungulwa ngo-1933 futhi usube umgogodla wokuxhumana nokuzijabulisa. Ukuqonda izimiso eziyisisekelo zendlela umsakazo we-FM osebenza ngayo kanye nemisebenzi yawo kunganikeza ukuqonda okujulile ngobunye bobuchwepheshe obubumbe kakhulu umhlaba wanamuhla. Njengoba ubuchwepheshe buqhubeka nokukhula, i-FM isalokhu ibalulekile futhi inikeza amathuba amasha azoqhubeka nokugcina nokwandisa indima yayo ekuxhumaneni komhlaba wonke.
Ngalolu lwazi oluyisisekelo, noma ubani angaqonda kangcono ubunzima nobuhle bobuchwepheshe esingase sibuthathe kalula ekuphileni kwansuku zonke.
