Tataiso ea ho Etsa Radio ka Sesebelisoa sa USB
Mehleng ena ea dijithale, seea-le-moea ha se sa tšoana le lipotoloho tse rarahaneng tsa analog, likhoele le li-capacitor tse kholo tsa ho lokisa. Kajeno, u ka haha tsamaiso ea seea-le-moea e sebetsang le e tenyetsehang ka thuso ea sebopeho sa USB. Khopolo ena e tsejoa ka tloaelo e le SDR (Software Defined Radio), seea-le-moea moo mesebetsi e mengata ea ts'ebetso e fetisetsoang ho software khomphuteng. Ka mokhoa oa SDR, u ka amohela (esita le ho fetisa, lisebelisoa tse ling) mefuta e fapaneng ea matšoao a seea-le-moea ka ho fetola tlhophiso ea software - ntle le ho qhaqha potoloho.
Sengoloa sena se akaretsa tataiso ea ho aha seea-le-moea se thehiloeng ho USB: ho tloha khopolo-taba le lisebelisoa tse hlokahalang, ho kenya software, ho ea ho liteko le ntlafatso. Sepheo sa mantlha se ho seea-le-moea se amohelang, kaha se sireletsehile haholoanyane 'me ha se hloke laesense ea ho fetisa.
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1. Ho utloisisa Khopolo ea Radio ka Sehokelo sa USB
Sebopeho sa USB mererong ea seea-le-moea hangata se sebetsa e le khokahano pakeng tsa sesebelisoa sa RF (maqhubu a seea-le-moea) le khomphutha. Ho na le mekhoa e 'meli e tsebahalang:
1. Karete ea Molumo ea USB + Potoloho e Bonolo ea Ka pele
Letšoao la seea-le-moea le theoleloa ho ba molumo ebe le kenngoa kareteng ea molumo ea USB. Mokhoa ona o loketse lihlopha tse itseng (tse kang HF) 'me o hloka potoloho e eketsehileng ea analog.
2. USB SDR Dongle (e sebetsang haholo)
Disebediswa tse kang RTL-SDR, Airspy, kapa SDRPlay di hapa matshwao a RF, di a fetolela ho data ya dijithale (I/Q), ebe di a romela khomphuteng ka USB. Software ya SDR e ntano etsa demodulation.
Bakeng sa ba qalang, khetho ea bobeli ke e bonolo ka ho fetisisa hobane e hloka ho kopanngoa hanyane 'me e na le tšehetso e kholo ea software.
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2. Lisebelisoa le Likarolo tse Hlokahalang
Lenane le latelang la likarolo tse sebelisoang hangata ho etsa seea-le-moea se thehiloeng ho USB ke lena:
Lisebelisoa
– USB SDR Dongle
Khetho e theko e tlase: RTL-SDR (RTL2832U chip + R820T2 tuner).
Ka kakaretso e khona ho amohela hoo e ka bang 24 MHz–1,7 GHz (ho latela mohlala le ho nka sampole ka kotloloho).
– Antena
E ka ba antenna e hahiloeng kahare, antenna ea telescopic, dipole e bonolo, kapa antenna ea kantle.
Khetho ea li-antenna e etsa qeto e kholo ea boleng ba kamohelo.
– Thapo ya Coaxial + adaptara ya sehokelo (SMA/MCX/BNC ho itshetlehile ka sesebediswa)
– Khomphutha/Laptop
Windows, Linux, kapa macOS. Bakeng sa RTL-SDR, Windows le Linux ke tsona tse atileng haholo.
– (Boikhethelo) LNA (Seholisa-lerata se Tlase)
E thusa ho matlafatsa matshwao a fokolang, haholo-holo bakeng sa di-antenna tse nyane.
– (Boikhethelo) Sefetola sa Bandpass/Notch
Ho molemo haeba ho na le tšitiso e matla (mohlala, matshwao a kgaso ya FM a "koenyang" dihlopha tse ding tsa mmino).
Software
– Software ea SDR: SDR (SDRSharp), HDSDR, CubicSDR, GQRX, kapa SDR++
– Bakhanni le lits'ebeletso: Zadig (Windows) ho kenya bakhanni ba USB ba loketseng
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3. Fumana Lipakane tsa Khaso tseo U Batlang ho li Fumana
Pele o kenya, fumana mofuta oa lets'oao leo u batlang ho le mamela. Mehlala e meng:
– Kgaso ya FM (88–108 MHz): diteishene tse bonolo ka ho fetisisa, tse ngata tse matla.
– AM Airband (118–137 MHz): puisano ea lifofane (ho latela sebaka).
– Lipuisano tsa VHF/UHF: radio ea baithaopi, li-repeater, kapa lits'ebeletso tse itseng (etsa bonnete ba hore li molaong).
– Boemo ba Leholimo ba NOAA (hoo e ka bang 162 MHz US), kapa tšebeletso ea boemo ba leholimo ba lehae haeba e fumaneha.
– HF (3–30 MHz): kgaso ya maqhubu a makgutshwane, HF ya baithaopi, jj. Bakeng sa RTL-SDR, ho hlokahala dibopeho tsa ho nka disampole ka ho toba kapa tsa ho fetola di-upconverter.
Sepheo sena se tla susumetsa khetho ea li-antenna le li-software.
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4. Ho kenya le ho hlophisa (Mohlala: RTL-SDR ho Windows)
Mohato oa 1: Kenya Software ea SDR
Khoasolla e 'ngoe ea li-app tsa SDR. SDR e tumme haholo bakeng sa ba qalang ka lebaka la sebopeho sa eona se bonolo ho se sebelisa.
Mohato oa 2: Kenya USB Driver (Zadig)
1. Kenya RTL-SDR koung ea USB.
2. Matha Zadig joalo ka motsamaisi.
3. Khetha sesebelisoa sa RTL-SDR (hangata se bontšoa e le “RTL2832U” kapa “Bulk-In, Interface”).
4. Khetha mokhanni oa WinUSB ebe u tobetsa Install/Replace Driver.
Mokhanni enoa o dumella ditshebediso tsa SDR ho fihlella data ya I/Q ho tswa ho dongle.
Mohato oa 3: Matha SDR le Khetha Mohloli
1. SDR e bulehileng.
2. Karolong ea Mohloli, khetha RTL-SDR (USB).
3. Tobetsa Qala ho qala ho amohela matshwao.
Haeba ho kenngwa ho nepahetse, o tla bona spectrum (phororo) e tsamaya.
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5. Mokhoa oa ho Sebelisa Software ea SDR ho Mamela Likhaso
A. Ho Beha Maqhubu
– Kenya maqhubu a reriloeng, mohlala 100.7 MHz bakeng sa FM.
– O ka boela wa tobetsa ditlhōrōng tsa matshwao a phatlalatso ho spectrum ho tsamaya kapele.
B. Ho Khetha Mokhoa oa ho Demodulation
Mokhoa o akaretsang:
– WFM bakeng sa kgaso ya FM (radio ya mmino)
– NFM bakeng sa puisano ea VHF/UHF (HT, repeater)
– AM bakeng sa leqhubu la moya, le mananeo a mang a AM
C. Ho Beha Bandwidth
Bophara ba mothapo bo tlameha ho tsamaellana le mofuta oa lets'oao:
– WFM hangata ke 150–250 kHz
– NFM 10–15 kHz
– Lebanta la moea la AM le ka bang 6–10 kHz (le itšetlehileng ka software)
Bokgoni ba modumo bo nepahetseng bo etsa hore modumo o hlake haholoanyane mme bo fokotsa tshitiso ho tswa ho kanale e haufi.
D. Phaello le AGC
Ho beha phaello ho bohlokoa haholo:
– Haeba keketseho e le tlase haholo: lets'oao le fokola, lerata lea busa.
– Hodimo haholo: matshwao a matla a ka imetsa/a sotha.
Leka ho tima AGC e iketsang ebe o lokisa keketseho ya letsoho ho fihlela spectrum e bonahala e hlakile ntle le "ho fufulelwa" (ho jara ho feteletseng) mme modumo o dula o hlwekile.
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6. Etsa Antena e Bonolo (Ea Khethoa Empa e Khothaletsoa)
Antenna e hahiloeng kahare ea dongle hangata ha e ntle haholo. Ho ntlafatsa ts'ebetso, o ka haha antenna e bonolo, joalo ka dipole bakeng sa FM (e ka bang 100 MHz).
Foromo ea bolelele ba maqhubu:
\[
\lambda = \frac{300}{f(MHz)}
\]
Bakeng sa 100 MHz: λ ≈ limithara tse 3, kahoo dipole eohle ea halofo ea leqhubu ke ≈ limithara tse 1,5.
Bolelele ba "leoto" le leng le le leng la dipole (leqhubu la ¼) ≈ 0,75 metres.
Etsa lithapo tse peli tsa ~75 cm ka 'ngoe, li hokahanye le thapo ea coaxial (e bohareng le e fatše), ebe u li kenya ka mola o otlolohileng kapa sebopeho sa T. Antenna ena e bonolo hangata e betere haholo ho feta antenna e nyane ea kamehla.
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7. Teko le Tharollo ea Mathata
Mathata a tloaelehileng le litharollo tsa 'ona ke ana:
1. Ha ho na lets'oao ho hang
– Etsa bonnete ba hore mokhanni o nepahetse (Zadig/WinUSB ho Windows).
– Etsa bonnete ba hore mohloli o ka har'a software ke RTL-SDR.
– Leka koung e 'ngoe ea USB 'me u qobe li-hub tsa USB tse theko e tlaase.
2. Letšoao le teng empa molumo o lerata
– Fetola mokhoa (WFM vs NFM vs AM).
– Beha bandwidth.
– Lokisa antenna kapa suthisa sebaka (haufi le fensetere/kantle).
3. Ho jara lintho tse ngata haholo (methapo e felletseng e matla)
– Fokotsa phaello.
– Sebelisa sefe sa FM notch haeba o fumana dihlopha tse ding tse sitisang kgaso ya FM.
– Boloka antenna hole le mehlodi ya tshitiso (di-router tsa Wi-Fi, ditjhaja tsa switching tse theko e tlase).
4. Maqhubu a ho fokotsa nako
– RTL-SDR e ka ba le liphoso tsa PPM.
– Lekanya PPM ka har'a software ka lets'oao la referense (mohlala, seteishene se matla sa FM, beacon, kapa maqhubu a tloaelehileng).
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8. Nts'etsopele e Eketsehileng
Hang ha radio ea hau ea USB e se e sebetsa, u ka atolosa ts'ebetso ea eona:
- Rekota sephara kapa molumo bakeng sa tlhahlobo
– Ho hlalosa dikhoutu tsa dijithale (mohlala, AIS, ADS-B, APRS) ho sebediswa software e eketsehileng
Ela Hloko: ka kopo etsa bonnete ba hore tšebeliso e latela melaoana ea lehae le melao ea boitšoaro ea lekunutu.
– Theha seteishene sa ho beha leihlo ka Raspberry Pi + SDR (seva e hole)
– Ho ekelitsoe LNA le li-filters bakeng sa boleng bo betere ba kamohelo
– Ho hlahloba sehlopha sa HF ka sesebelisoa sa ho fetola (haeba dongle e sa tshehetse ho nka sampole ka ho toba hantle)
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Qetello
Ho haha seea-le-moea ka sebopeho sa USB ke tsela ea sejoale-joale le e bonolo ea ho hlahloba lefats'e la RF ntle le ho etsa meralo ea lipotoloho tse rarahaneng tsa analog. Ka dongle ea USB SDR, antenna e ntle, le software ea SDR, u ka hlahloba lihlopha tse fapaneng tsa seea-le-moea 'me ua utloisisa ka mahlo sephara. Linotlolo tsa katleho ke lintho tse tharo: bakhanni ba nepahetseng, litlhophiso tse nepahetseng tsa software, le antenna e nepahetseng.
Haeba o ka rata, nka fetola tataiso ena hore e be mofuta o batlang o le tekheniki (mohlala, e tlatselletsoa ka dikgothaletso tsa mohlala wa RTL-SDR, di-antenna schematics, kapa mehato ya ho kenya e ikgethang ya Linux/Raspberry Pi), kapa ka e etsa bakeng sa sepheo se ikgethang jwalo ka FM feela, airband, kapa ADS-B.
