1. Kutsika Mwachangu - Popeza mphamvu yothandiza yomwe ili m'magulu ang'onoang'ono ndi yaying'ono, kotero mphamvu ya AM system ndiyotsika.

2. Malo Ogwirira Ntchito Ochepa - Kuchuluka kwa ntchito kumakhala kochepa chifukwa cha kuchepa kwachangu. Choncho, kufalitsa zizindikiro kumakhala kovuta.

3. Phokoso mu Reception - Pamene wolandira wailesi amavutika kusiyanitsa kusiyana kwa matalikidwe a matalikidwe omwe amaimira phokoso ndi omwe ali ndi zizindikiro, phokoso lolemera limakonda kuchitika polandira.

4. Maubwino Osamveka bwino - Kuti mupeze kulandila kokhulupilika, ma frequency onse amawu mpaka 15 KiloHertz akuyenera kupangidwanso ndipo izi zimafunikira bandwidth ya 10 KiloHertz kuti achepetse kusokonezedwa ndi mawayilesi oyandikana nawo. Chifukwa chake mumawayilesi owulutsira a AM mawu amawu amadziwika kuti ndi otsika.

1. Kuwulutsa pawailesi

2. Kuwulutsa kwa TV

3. Khomo la garaja limatsegula ma remoti opanda makiyi

4. Kutumiza zizindikiro za TV

5. Kuyankhulana kwawayilesi kwakanthawi kochepa

6. Njira ziwiri zoyankhulirana ndi wailesi

Zithunzi za VSB-SC

1. Tanthauzo - Chovala cham'mbali (polankhulana pawailesi) ndi bandesi yam'mbali yomwe idadulidwa pang'ono kapena kuponderezedwa.

2. Gusaba Akazi Gashya - Makanema apa TV ndi mawayilesi a wailesi

3. ntchito - Imatumiza ma sign a TV

Zithunzi za SSB-SC

1. Tanthauzo - Single-sidebandmodulation (SSB) ndikuwongolera kwa matalikidwe omwe amagwiritsa ntchito mphamvu zamagetsi ndi bandwidth.

2. Gusaba Akazi Gashya - Makanema apa TV & mawayilesi a Shortwave Radio

3. ntchito -Kulumikizana ndi wailesi ya Shortwave

Chithunzi cha DSB-SC

1. Tanthauzo - Pakulankhulana pawailesi, gulu lakumbali ndi gulu la ma frequency omwe amamukweza kuposa kapena kutsika kuposa ma frequency onyamula, okhala ndi mphamvu chifukwa cha kusintha kwanthawi yake.

2. Gusaba Akazi Gashya - Makanema apa TV ndi mawayilesi a wailesi

3. ntchito - Njira ziwiri zolumikizirana ndi wailesi

Kodi Amplitude Modulation (AM) ndi chiyani?

- "Kusinthasintha ndi njira yopititsira patsogolo chizindikiro chochepa chafupipafupi pamtunda wapamwamba chonyamulira chizindikiro."

- "Njira yosinthira imatha kufotokozedwa ngati kusinthasintha kwa mafunde a RF carriers molingana ndi luntha kapena chidziwitso mu siginecha yotsika pafupipafupi."

- "Kusinthasintha kumatanthauzidwa ngati njira yomwe mikhalidwe ina, nthawi zambiri matalikidwe, pafupipafupi kapena gawo, la chonyamulira limasiyanasiyana malinga ndi mtengo wanthawi yomweyo wamagetsi ena, otchedwa modulating voltage."

N'chifukwa Chiyani Kusinthasintha Kumafunikira?

1. Ngati mapulogalamu anyimbo aŵiri aimbidwa nthawi imodzi patali, zingakhale zovuta kuti munthu amvetsere gwero limodzi koma osamva gwero lachiŵiri. Popeza kuti mawu onse a nyimbo amakhala ndi ma frequency ofanana, amapanga pafupifupi 50 Hz mpaka 10KHz. Ngati pulogalamu yomwe mukufuna isinthidwa kukhala ma frequency pakati pa 100KHz ndi 110KHz, ndipo pulogalamu yachiwiri idasunthidwa mpaka pakati pa 120KHz ndi 130KHz, Kenako mapulogalamu onsewo adaperekabe bandwidth ya 10KHz ndipo omvera amatha (posankha gulu) kupeza pulogalamuyo. mwa kusankha kwake. Wolandira amatsitsa ma frequency osankhidwa okha kupita ku 50Hz kupita ku 10KHz.

2. Chifukwa chachiwiri chaukadaulo chosinthira chizindikiro cha uthenga kuma frequency apamwamba chikugwirizana ndi kukula kwa mlongoti. Ndikoyenera kudziwa kuti kukula kwa mlongoti kumayenderana mosiyana ndi mafupipafupi omwe amawunikira. Izi ndi 75 metres pa 1 MHz koma pa 15KHz zawonjezeka kufika mamita 5000 (kapena kupitirira 16,000 mapazi) mlongoti woyimirira wa kukula uku ndizosatheka.

3. Chifukwa chachitatu chosinthira chonyamulira cha ma frequency apamwamba ndichoti mphamvu ya RF (radio frequency) idzayenda mtunda wautali kuposa kuchuluka kwa mphamvu zomwe zimaperekedwa ngati mphamvu yamawu.

Mitundu ya Kusinthasintha

Chizindikiro chonyamulira ndi sine wave pama frequency onyamula. Pansipa equation ikuwonetsa kuti sine wave ili ndi mikhalidwe itatu yomwe ingasinthidwe.

Mphamvu yamagetsi nthawi yomweyo (E) =Ec(max)Sin(2πfct + θ)

Mawu omwe angakhale osiyana ndi carrier voltage Ec, carrier frequency fc, ndi carrier phase angle. θ. Chifukwa chake mitundu itatu yosinthira ndizotheka.

1. Kusinthasintha kwa matalikidwe

Kusinthasintha kwa matalikidwe ndikokwera kapena kutsika kwa voteji chonyamulira (Ec), zinthu zina zonse zidzatsalira.

2. Kusinthasintha pafupipafupi

Kusinthasintha kwafupipafupi ndikusintha kwa ma frequency onyamula (fc) ndi zinthu zina zonse zotsalira.

3. Kusintha kwa Gawo

Phase modulation ndikusintha kwa gawo lonyamula (θ). Mbali ya gawo silingasinthe popanda kukhudzanso kusintha kwafupipafupi. Chifukwa chake, kusinthika kwa gawo ndi njira yachiwiri yosinthira pafupipafupi.

KUFOTOKOZA KWA AM

Njira yosinthira matalikidwe amtundu wonyamula ma frequency apamwamba malinga ndi chidziwitso chomwe chiyenera kupatsirana, kusunga ma frequency ndi gawo la mafunde onyamulira osasinthika amatchedwa Amplitude Modulation. Chidziwitsocho chimatengedwa ngati siginecha yosinthira ndipo chimayikidwa pamwamba pa mafunde onyamulira powagwiritsa ntchito onse awiri ku modulator. Chithunzi chatsatanetsatane chowonetsa njira yosinthira matalikidwe chaperekedwa pansipa.

Monga tawonera pamwambapa, mafunde onyamulira amakhala ndi zozungulira zabwino komanso zoyipa. Zozungulira zonsezi zimasiyanasiyana malinga ndi zomwe zitumizidwa. Chonyamuliracho chimakhala ndi mafunde a sine omwe matalikidwe ake amatsata kusiyanasiyana kwa mafunde a modulating. Chonyamuliracho chimasungidwa mu envelopu yopangidwa ndi modulating wave. Kuchokera pachithunzichi, mutha kuwonanso kuti kusiyanasiyana kwa matalikidwe a chonyamulira chapafupipafupi kumakhala pafupipafupi komanso kuchuluka kwa mafunde onyamula ndi ofanana ndi kuchuluka kwa mafunde obwera.

Kusanthula kwa Amplitude Modulation Carrier Wave

Tiyeni vc = Vc Sin wct

vm = Vm Sin wmt

vc - Mtengo wanthawi yomweyo wa chonyamulira

Vc - Mtengo wapamwamba kwambiri wa chonyamulira

Wc - Angular liwiro la chonyamulira

vm - Mtengo wanthawi yomweyo wa siginecha yosinthira

Vm - Mtengo wapamwamba wa siginecha yosinthira

wm - Kuthamanga kwa angular kwa siginecha yosinthira

fm - Kusintha ma frequency azizindikiro

Tiyenera kuzindikira kuti mbali ya gawo imakhalabe yosasinthika munjira iyi. Motero akhoza kunyalanyazidwa.

Tiyenera kuzindikira kuti mbali ya gawo imakhalabe yosasinthika munjira iyi. Motero akhoza kunyalanyazidwa.

Kukula kwa mafunde onyamulira kumasiyanasiyana pa fm. Mafunde opangidwa ndi matalikidwe amaperekedwa ndi equation A = Vc + vm = Vc + Vm Sin wmt

= Vc [1+ (Vm/Vc Sin wmt)]

= Vc (1 + mSin wmt)

m - Modulation Index. Chiŵerengero cha Vm/Vc.

Nthawi yomweyo mtengo wa mafunde osinthika amaperekedwa ndi equation v = A Sin wct = Vc (1 + m Sin wmt) Sin wct

= Vc Sin wct + mVc (Sin wmt Sin wct)

v = Vc Sin wct + [mVc/2 Cos (wc-wm)t – mVc/2 Cos (wc + wm)t]

Equation yomwe ili pamwambapa ikuyimira kuchuluka kwa ma sine mafunde atatu. Imodzi yokhala ndi matalikidwe a Vc ndi mafupipafupi a wc/2, yachiwiri yokhala ndi matalikidwe a mVc/2 ndi ma frequency a (wc – wm)/2 ndi yachitatu yokhala ndi matalikidwe a mVc/2 ndi pafupipafupi (wc) + wm)/2 .

Pochita mayendedwe aang'ono a chonyamuliracho amadziwika kuti ndiakuluakulu kuposa kuthamanga kwa angular kwa siginecha yosinthira (wc >> wm). Chifukwa chake, ma equation achiwiri ndi achitatu a cosine ali pafupi kwambiri ndi ma frequency onyamula. Equation ikuimiridwa mojambula monga momwe zilili pansipa.

Frequency Spectrum ya AM Wave

Mafupipafupi apambali - (wc – wm)/2

Mafupipafupi am'mbali - (wc +wm)/2

Zigawo zafupipafupi zomwe zimapezeka mu mafunde a AM zimayimiridwa ndi mizere yowongoka yomwe ili pafupi ndi ma frequency axis. Kutalika kwa mzere uliwonse wolunjika kumakokedwa molingana ndi matalikidwe ake. Popeza mayendedwe aang'ono a chonyamulira ndi chachikulu kuposa liwiro la angular la siginecha yosinthira, matalikidwe a ma frequency a band am'mbali sangathe kupitilira theka la matalikidwe a chonyamulira.

Chifukwa chake sipadzakhala kusintha kulikonse koyambira, koma ma frequency a band (wc - wm)/2 ndi (wc +wm)/2 adzasinthidwa. Yoyamba imatchedwa chapamwamba mbali band (USB) pafupipafupi ndipo kenako amadziwika kuti low side band (LSB) pafupipafupi.

Popeza ma frequency a siginecha wm/2 alipo m'magulu am'mbali, zikuwonekeratu kuti gawo lamagetsi onyamula silitumiza chidziwitso chilichonse.

Ma frequency awiri am'mbali amapangidwa ngati chonyamuliracho chikusinthidwa ndi ma frequency amodzi. Ndiko kuti, mafunde a AM ali ndi bandi m'lifupi kuchokera (wc - wm)/2 mpaka (wc +wm)/2, ndiko kuti, 2wm/2 kapena kawiri ma frequency azizindikiro amapangidwa. Pamene siginecha yosinthira imakhala ndi ma frequency opitilira amodzi, ma frequency amitundu iwiri amapangidwa ndi ma frequency aliwonse. Momwemonso ma frequency awiri a ma modulating siginali 2 LSB's ndi 2 USB's ma frequency adzapangidwa.

Magulu am'mbali a ma frequency omwe amapezeka pamwamba pa ma frequency onyamula adzakhala ofanana ndi omwe ali pansipa. Ma frequency a band am'mbali omwe amapezeka pamwamba pa ma frequency onyamula amadziwika kuti ndi gulu lakumtunda ndipo onse omwe ali pansi pa ma frequency onyamula amakhala a gulu lakumunsi lakumunsi. Ma frequency a USB amayimira ma frequency ena omwe amasinthira payekha ndipo ma frequency a LSB amayimira kusiyana pakati pa ma frequency modulating ndi ma frequency onyamula. Bandwidth yonse imayimiridwa malinga ndi kuchuluka kwa ma modulating pafupipafupi ndipo ndi yofanana ndi ma frequency awa.

Modulation Index (m)

Chiŵerengero chapakati pa kusintha kwa matalikidwe a mafunde onyamulira kupita ku matalikidwe a mafunde onyamulira wamba amatchedwa modulation index. Imaimiridwa ndi chilembo ‗m'.

Itha kufotokozedwanso ngati kuchuluka komwe matalikidwe a mafunde onyamulira amasiyanitsidwa ndi ma modulating sign. m = Vm/Vc.

Peresenti yosinthira, %m = m*100 = Vm/Vc * 100

Kusinthasintha kwapakati kumakhala pakati pa 0 ndi 80%.

Njira ina yosonyezera ndondomeko yosinthira ndi kutengera kuchuluka kwake komanso kuchepera kwa matalikidwe a mafunde onyamula modulated. Izi zikuwonetsedwa mu chithunzi pansipa.

2 Vin = Vmax - Vmin

Vin = (Vmax – Vmin)/2

Vc = vmax - vin

= Vmax – (Vmax-Vmin)/2 =(Vmax + Vmin)/2

Kuyika miyeso ya Vm ndi Vc mu equation m = Vm/Vc , timapeza

M = Vmax – Vmin/Vmax + Vmin

Monga tanenera kale, mtengo wa ‗m' uli pakati pa 0 ndi 0.8. Mtengo wa m umatsimikizira mphamvu ndi mtundu wa chizindikiro chopatsirana. Mu mafunde a AM, siginecha ili mumitundu yosiyanasiyana ya matalikidwe a chonyamulira. Chizindikiro cha audio chomwe chimaperekedwa chidzakhala chofooka ngati mafunde onyamulira amangosinthidwa pang'ono kwambiri. Koma ngati mtengo wa m upitilira umodzi, zotulutsa zotulutsa zimatulutsa kupotoza kolakwika.

Ubale Wamphamvu mumayendedwe a AM

Mafunde osinthika amakhala ndi mphamvu zochulukirapo kuposa zomwe anali nazo ndi mafunde onyamulira asanasinthe. Magawo onse amphamvu pakusinthira matalikidwe amatha kulembedwa motere:

Ptotal = Pcarrier + PLSB + PUSB

Poganizira kukana kwina monga kukana kwa mlongoti R.

Wonyamula = [(Vc/√2)/R]2 = V2C/2R

Gulu lililonse lakumbali lili ndi mtengo wa m/2 Vc ndi rms mtengo wa mVc/2√2. Choncho mphamvu mu LSB ndi USB akhoza kulembedwa ngati

PLSB = PUSB = (mVc/2√2) 2/R = m2/4*V2C/2R = m2/4 Wonyamula

Ptotal = V2C/2R + [m2/4*V2C/2R] + [m2/4*V2C/2R] = V2C/2R (1 + m2/2) = Pcarrier (1 + m2/2)

Mu ntchito zina, chonyamulira ndi imodzi modulated ndi angapo sinusoidal modulating siginecha. Zikatero, chiwerengero cha modulation index chimaperekedwa ngati

Mt = √(m12 + m22 + m32 + m42 + …..

Ngati Ic ndi Izo ndi ma rms amakono osasinthika komanso osinthika omwe ali pano ndipo R ndiye kukana komwe izi zikuyenda, ndiye

Ptotal/Pcarrier = (It.R/Ic.R)2 = (It/Ic)2

Ptotal/Carrier = (1 + m2/2)

Iwo/Ic = 1 + m2/2

1. Kutanthauza kusinthasintha?

Kusinthasintha ndi njira yomwe mawonekedwe ena amtundu wonyamula ma frequency apamwamba amasiyanasiyana malinga ndi mtengo wanthawi yomweyo wa siginecha yosinthira.

2. Ndi mitundu yanji yakusintha kwa analogi?

Kusinthasintha kwa matalikidwe.

Kusinthasintha kwa Angle

Kusinthasintha pafupipafupi

Kusintha kwa gawo.

3. Kutanthauza kuya kwa kusinthasintha.

Imatanthauzidwa ngati chiŵerengero pakati pa matalikidwe a uthenga ndi matalikidwe a chonyamulira. m=Em/Ec

4. Kodi kusinthasintha kwa mawu ndi kotani?

Pansi pa kusinthasintha. m <1

Kusintha kofunikira m=1

Kupitilira modulation m>1

5. Kodi kusinthasintha mawu kumafunika chiyani?

- Zofunikira pakusinthira:

- Kusavuta kufalitsa

- Zochulukirapo

- Phokoso lochepa

- bandwidth yocheperako

- Kugawa pafupipafupi

- Chepetsani malire a zida

6. Kodi ma modulators a AM ndi ati?

Pali mitundu iwiri ya AM modulators. Ali

- Linear modulators

- Ma modulator opanda mzere

Linear modulators amagawidwa motere

- Transistor module

Pali mitundu itatu ya transistor modulator.

- Wosonkhanitsa modulator

- Emitter modulator

- Maziko odulira

- Kusintha ma modulators

Non-linear modulators amagawidwa motere

- Square malamulo modulator

- Product module

- Kusamala moyenera

7. Kodi pali kusiyana kotani pakati pa kusinthasintha kwapamwamba ndi kutsika?

Pakusinthasintha kwapamwamba kwambiri, modulator amplifier imagwira ntchito mwamphamvu kwambiri ndipo imapereka mphamvu mwachindunji ku mlongoti. Pakusinthasintha kwapang'onopang'ono, ma modulator amplifier amachita kusinthasintha pamagulu otsika kwambiri. Chizindikiro chosinthidwacho chimakulitsidwa mpaka kumlingo wapamwamba kwambiri ndi amplifier yamphamvu ya gulu B. Amplifier imadyetsa mphamvu ku mlongoti.

8. Kutanthauza Kuzindikira (kapena) Kuchepetsa.

Kuzindikira ndi njira yopezera ma modulating sign kuchokera kwa chonyamulira chosinthidwa. Mitundu yosiyanasiyana ya zowunikira imagwiritsidwa ntchito pamitundu yosiyanasiyana yosinthira.

9. Kutanthauzira matalikidwe kusinthasintha.

Mu kusinthasintha kwa matalikidwe, matalikidwe a siginecha yonyamulira amasiyanasiyana malinga ndi kusiyanasiyana kwa matalikidwe a siginecha yosinthira.

Chizindikiro cha AM chikhoza kuyimiridwa mwamasamu monga, eAM = (Ec + Em sinωmt ) sinωct ndipo ndondomeko yosinthira imaperekedwa monga, m = Em / EC (kapena) Vm/Vc

10. Kodi Super Heterodyne Receiver ndi chiyani?

Wolandila wamkulu wa heterodyne amasintha ma frequency onse a RF omwe akubwera kukhala ma frequency otsika, otchedwa intermediate frequency (IF). IF iyi ndiye matalikidwe ndikuzindikirika kuti mupeze chizindikiro choyambirira.

11. Kodi kamvekedwe ka toni imodzi ndi kusinthasintha kamvekedwe kosiyanasiyana ndi chiyani?

- Ngati kusinthasintha kumachitidwa pa siginecha ya uthenga yokhala ndi ma frequency opitilira chimodzi ndiye kuti kusinthaku kumatchedwa kusinthasintha kwa ma toni ambiri.

- Ngati kusinthasintha kumachitidwa pa chizindikiro cha uthenga ndi gawo limodzi lafupipafupi ndiye kuti kusinthaku kumatchedwa single tone modulation.

12. Yerekezerani AM ndi DSB-SC ndi SSB-SC.

13. Kodi ubwino wa VSB-AM ndi chiyani?

- Ili ndi bandwidth yayikulu kuposa SSB koma yocheperako kuposa DSB system.

- Kutumiza kwamagetsi kwakukulu kuposa DSB koma kucheperako kachitidwe ka SSB.

- No otsika pafupipafupi gawo anataya. Chifukwa chake imapewa kupotoza kwa gawo.

14. Mupanga bwanji DSBSC-AM?

Pali njira ziwiri zopangira DSBSC-AM monga

- Modulator yoyenera

- mphete modulators.

15. Kodi ubwino wa ring modulator ndi chiyani?

- Kutulutsa kwake ndikokhazikika.

- Palibe gwero lamphamvu lakunja kuti mutsegule ma diode. c).Pafupifupi palibe kukonza.

- Moyo wautali.

16. Kutanthauza Demodulation.

Demodulation kapena kuzindikira ndi njira yomwe ma modulating voltage amabwezeretsedwa kuchokera ku siginecha yosinthidwa. Ndi njira yosinthira modulation. Zida zomwe zimagwiritsidwa ntchito potsitsa kapena kuzindikira zimatchedwa ma demodulators kapena zowunikira. Pakusinthasintha kwa matalikidwe, zowunikira kapena ma demodulators amagawidwa motere: 

- Zozindikira za Square-law

- Zofufuza za envelopu

17. Kutanthauza Multiplexing.

Multiplexing imatanthauzidwa ngati njira yotumizira mauthenga angapo nthawi imodzi panjira imodzi.

18. Tanthauzirani Frequency Division Multiplexing.

Kuchulukitsa kwa magawo pafupipafupi kumatanthauzidwa ngati ma siginecha ambiri amatumizidwa nthawi imodzi ndi chizindikiro chilichonse chokhala ndi ma frequency osiyanasiyana mkati mwa bandwidth wamba.

19. Tanthauzirani Gulu la Alonda.

Magulu Oyang'anira Amayambitsidwa mu FDM kuti apewe kusokoneza kulikonse pakati pa mayendedwe oyandikana nawo. Kukulitsa magulu a alonda, Kuchepetsa kusokoneza.

20. Tanthauzirani SSB-SC.

- SSB-SC imayimira Single Side Band Suppressed Carrier

- Pamene gulu limodzi lokha litumizidwa, kusinthaku kumatchedwa Single side band modulation. Imatchedwanso SSB kapena SSB-SC.

21. Tanthauzirani DSB-SC.

Pambuyo kusinthasintha, njira yopatsira zingwe zam'mbali (USB, LSB) yokha ndikupondereza chonyamuliracho imatchedwa Double Side Band-Suppressed Carrier.

22. Kodi kuipa kwa DSB-FC ndi chiyani?

- Kuwonongeka kwamagetsi kumachitika mu DSB-FC

- DSB-FC ndi bandwidth yosakwanira dongosolo.

23. Kutanthauza Kuzindikira Kogwirizana.

Panthawi yonyamula Demodulation imakhala yogwirizana kapena yolumikizidwa pafupipafupi komanso gawo, ndi mafunde oyambira omwe amagwiritsidwa ntchito kupanga mafunde a DSB-SC.

Njira yodziwira iyi imatchedwa kuzindikira kogwirizana kapena kuzindikira kofanana.

24. Kodi Vestigial Side Band Modulation ndi chiyani?

Vestigial Sideband Modulation imatanthauzidwa ngati kusintha komwe gulu limodzi lambali limaponderezedwa pang'ono ndipo chotsalira cha gulu linalo chimaperekedwa kuti chibwezere kuponderezedwako.

25. Kodi ubwino wa chizindikiro sideband kufala ndi chiyani?

- Kugwiritsa ntchito mphamvu

- Kusunga bandwidth

- Kuchepetsa phokoso

26. Kodi kuipa kwa single side band transmission ndi chiyani?

- Zolandila zovuta: Makina amtundu umodzi amafunikira olandila ovuta komanso okwera mtengo kuposa kutumiza kwa AM.

- Kukonza zovuta: Olandila gulu limodzi amafunikira nyimbo zovuta komanso zolondola kuposa zolandila wamba za AM.

27. Fananizani ma modulator a mzere ndi omwe si a mzere?

Linear Modulators

- Kusefa kwakukulu sikofunikira.

- Ma modulators awa amagwiritsidwa ntchito pakusinthasintha kwapamwamba.

- Mphamvu yamagetsi yonyamula ndi yayikulu kwambiri kuposa ma voliyumu amagetsi.

Non Linear Modulators

- Kusefa kwakukulu kumafunika.

- Ma modulators awa amagwiritsidwa ntchito posintha pang'ono.

- Mphamvu yamagetsi yosinthira ndi yayikulu kwambiri kuposa voteji yonyamula.

28. Kodi kumasulira pafupipafupi ndi chiyani?

Tiyerekeze kuti siginecha ndi bandi yocheperako kufupipafupi kuchokera ku f1 kupita kufupi f2. Njira yomasulira pafupipafupi ndi imodzi yomwe chizindikiro choyambirira chimasinthidwa ndi chizindikiro chatsopano chomwe mawonekedwe ake amachoka ku f1' ndi f2' ndi pomwe chizindikiro chatsopano chimanyamula, mu mawonekedwe obweza chidziwitso chofanana ndi chomwe chidanyamulidwa ndi chizindikiro choyambirira.

29. Kodi ndi mikhalidwe iŵiri yotani yozindikiridwa m’matembenuzidwe kaŵirikaŵiri?

- Kutembenuka Kwambiri: Pamenepa omasuliridwa chonyamulira pafupipafupi ndi wamkulu kuposa chonyamulira ukubwera

- Kutembenuka Pansi: Pamenepa omasuliridwa chonyamulira pafupipafupi ndi laling'ono kuposa kuchuluka chonyamulira pafupipafupi.

Chifukwa chake, siginecha yocheperako ya FM imafunikira bandwidth yofananira monga chizindikiro cha AM.

30. Kodi BW ya AM wave ndi chiyani?

 Kusiyana pakati pa ma frequency awiriwa ndi ofanana ndi bandwidth ya AM wave.

 Choncho, Bandwidth, B = (fc + fm) - (fc - fm) B = 2fm

31. Kodi chizindikiro cha BW cha DSB-SC ndi chiyani?

Bandwidth, B = (fc + fm) - (fc - fm) B = 2f

Ndizodziwikiratu kuti bandwidth ya DSB-SC modulation ndi yofanana ndi mafunde a AM.

32. Kodi njira zowonetsera zizindikiro za DSB-SC ndi ziti?

Chizindikiro cha DSB-SC chikhoza kuchotsedwa potsatira njira ziwiri:

- Njira yodziwira yolumikizana.

- Kugwiritsa ntchito chojambulira envelopu pambuyo pobwezeretsanso chonyamulira.

33. Lembani ntchito za kusintha kwa Hilbert?

- Kupanga ma sign a SSB,

- Pakupanga zosefera zamtundu wocheperako,

- Kuyimira chizindikiro cha band pass.

34. Kodi njira zopangira chizindikiro cha SSB-SC ndi ziti?

Zizindikiro za SSB-SC zitha kupangidwa ndi njira ziwiri monga pansipa:

-Kusankhana pafupipafupi kapena kusefa.

- Njira ya tsankho kapena njira yosinthira gawo.

MALO OGWIRITSIRA NTCHITO

1. Kusintha kwa matalikidwe: Kusinthasintha kwa mafunde mosiyanasiyana matalikidwe ake, omwe amagwiritsidwa ntchito makamaka ngati njira youlutsira mawu omvera pophatikiza ndi mafunde onyamula wailesi.

2. Mlozera wosinthira: (kuzama kwakusintha) kwa dongosolo losinthira kumatanthawuza kuchuluka kwa kusinthika kwa chizindikiro chonyamulira kumasiyanasiyana mozungulira mulingo wake wosasinthika.

3. Narrowband FM: Ngati index yosinthira ya FM ikasungidwa pansi pa 1, ndiye kuti ma FM opangidwa amatengedwa ngati gulu lopapatiza la FM.

4. Kusinthasintha pafupipafupi (FM): ma encoding a chidziwitso mu mafunde onyamula posintha ma frequency apompopompo a mafunde.

5. Kutanthauzira: Mlingowo umasankhidwa mosamala kuti usachulukitse chosakaniza pamene zizindikiro zamphamvu zilipo, koma zimathandiza kuti zizindikirozo zikwezedwe mokwanira kuti zitsimikizire kuti chiŵerengero chabwino cha phokoso chimapezeka.

6. Kusinthasintha: Njira yomwe machitidwe ena a mafunde onyamulira amasiyanasiyana malinga ndi chizindikiro cha uthenga.

Mafupipafupi (SW)

Wailesi ya Shortwave ili ndi mitundu yayikulu - imatha kulandiridwa masauzande a mailosi kuchokera pa chowulutsira, ndipo ma transmitter amatha kuwoloka nyanja ndi mapiri. Izi zimapangitsa kukhala koyenera kufikira mayiko opanda wailesi kapena kumene kuwulutsa kwachikristu kuli koletsedwa. Mwachidule, wailesi ya shortwave imagonjetsa malire, kaya ndi malo kapena ndale. Kutumiza kwa SW ndikosavuta kulandira, nawonso: ngakhale mawayilesi otsika mtengo, osavuta amatha kutenga chizindikiro.

Mphamvu za wailesi ya shortwave zimapangitsa kuti ikhale yoyenera kudera la Feba Kuzunzidwa Mpingo. Mwachitsanzo, kumadera aku North East Africa komwe kuwulutsa kwachipembedzo ndikoletsedwa mkati mwa dzikolo, anzathu akumaloko amatha kupanga zomvera, kuzitumiza kunja kwa dziko ndikuziwonetsanso kudzera pa SW popanda chiopsezo choimbidwa mlandu.  

Yemen pakali pano ikukumana ndi vuto lalikulu komanso lachiwawa ndi mkangano womwe ukuyambitsa ngozi yayikulu yothandiza anthu. Komanso kupereka chilimbikitso chauzimu, anzathu amaulutsa nkhani zokhudzana ndi chikhalidwe cha anthu, thanzi ndi moyo wabwino monga momwe Akhristu amaonera.  

M’dziko limene Akristu amangopanga 0.08% yokha ya anthu ndipo amazunzidwa chifukwa cha chikhulupiriro chawo, Reality Church ndi pulogalamu yapawayilesi ya mphindi 30 yomwe imathandizira okhulupirira aku Yemeni m'zilankhulo zakomweko. Omvera amatha kupeza mawayilesi othandizira mwachinsinsi komanso mosadziwika.  

Njira yamphamvu yofikira midzi yonyozedwa kudutsa malire, shortwave ndiyothandiza kwambiri kufikira anthu akutali ndi Uthenga Wabwino ndipo, m’madera amene Akristu amazunzidwa, imasiya omvera ndi owulutsa nkhani kukhala opanda mantha odzudzulidwa. 

Mafunde apakati (MW)

Wailesi yapakati-wave nthawi zambiri imagwiritsidwa ntchito powulutsira m'deralo ndipo ndi yabwino kwa anthu akumidzi. Ndi njira yapakatikati yopatsirana, imatha kufikira madera akutali ndi chizindikiro champhamvu, chodalirika. Kutumiza kwa mafunde apakati kumatha kuulutsidwa kudzera pamawayilesi okhazikika - pomwe maukondewa alipo.  

In kumpoto kwa India, zikhulupiriro za chikhalidwe cha kumaloko zimasiya akazi kukhala oponderezedwa ndipo ambiri amangokhala m’nyumba zawo. Kwa amayi omwe ali ndi udindowu, mauthenga ochokera ku Feba kumpoto kwa India (pogwiritsa ntchito mawailesi okhazikitsidwa) ndi njira yofunikira kwambiri yolumikizana ndi mayiko akunja. Mapologalamu ake okhudzana ndi zikhulupiriro zake amapereka maphunziro, chitsogozo chaumoyo komanso kuyikapo ndemanga pazaufulu wa amayi, zomwe zimalimbikitsa kukambirana zauzimu ndi amayi omwe amalumikizana ndi wayilesi. Pamenepa wailesi ikubweretsa uthenga wachiyembekezo ndi mphamvu kwa amayi omwe akumvetsera kunyumba.   

Kuzungulira Kwambiri (FM)

Kwa wayilesi yochokera mdera, FM ndi mfumu! 

Radio Umoja FM ku DRC yomwe idakhazikitsidwa posachedwapa, ndicholinga chopereka mawu kwa anthu ammudzi. FM imapereka chizindikiritso chachifupi - nthawi zambiri kulikonse komwe mungawone chowulutsira, chokhala ndi mawu abwino kwambiri. Imatha kuwulutsa dera laling'ono kapena tauni yayikulu - kupangitsa kuti ikhale yabwino kwa wayilesi yomwe imayang'ana kwambiri malo omwe amalankhula zakumaloko. Ngakhale mawayilesi amfupi ndi mafunde apakatikati amatha kukhala okwera mtengo kugwira ntchito, chiphaso cha wayilesi ya FM yapagulu ndichotsika mtengo kwambiri. 

Afno FM, mnzake wa Feba ku Nepal, amapereka malangizo ofunikira azaumoyo kumadera aku Okhaldhunga ndi Dadeldhura. Kugwiritsa ntchito ma FM kumawalola kuyika zidziwitso zofunika, momveka bwino, kumadera omwe akuwunikiridwa. Kumidzi yaku Nepal, anthu akukayikira zipatala ndipo matenda ena odziwika bwino amawonedwa ngati osavomerezeka. Pali kufunikira kwenikweni kwa upangiri waumoyo wodziwa bwino, wopanda kuweruza komanso Afno FM zimathandiza kukwaniritsa chosowa ichi. Gululi limagwira ntchito mogwirizana ndi zipatala zam'deralo pofuna kupewa ndi kuchiza matenda omwe anthu ambiri amakumana nawo (makamaka omwe ali ndi tsankho) komanso kuthana ndi mantha a anthu am'deralo kwa akatswiri azachipatala, kulimbikitsa omvera kuti akapeze chithandizo chamankhwala kuchipatala akafuna. FM imagwiritsidwanso ntchito pa wailesi yankho lachangu - ndi chowulutsira cha 20kg FM chopepuka chotengera madera omwe akhudzidwa ndi tsoka ngati gawo la situdiyo yosavuta yonyamula masutukesi. 

Wailesi Yapaintaneti

Kukula mwachangu kwaukadaulo wozikidwa pa intaneti kumapereka mwayi waukulu wowulutsa pawailesi. Masiteshoni opezeka pa intaneti ndi ofulumira komanso osavuta kukhazikitsa (nthawi zina amatenga sabata imodzi kuti ayambe kugwira ntchito! Zitha kukhala zotsika mtengo kuposa zotumizira nthawi zonse.

Ndipo chifukwa intaneti ilibe malire, omvera pawailesi pa intaneti amatha kufikira padziko lonse lapansi. Choyipa chimodzi n’chakuti wailesi ya pa Intaneti imadalira pa Intaneti ndiponso kuti womvera azitha kugwiritsa ntchito kompyuta kapena foni yam’manja.  

M’chiŵerengero cha padziko lonse cha anthu 7.2 biliyoni, atatu mwa asanu, kapena 4.2 biliyoni, sakupezabe Intaneti nthaŵi zonse. Ntchito zamawayilesi ammudzi pa intaneti ndiye kuti pakadali pano sizoyenera kumadera ena osauka kwambiri komanso osafikirika kwambiri padziko lapansi.

Amplitude modulation (AM) ndiye njira yakale kwambiri yosinthira yomwe imadziwika. Mawayilesi oyamba owulutsa anali AM, koma ngakhale m'mbuyomu, CW kapena mafunde osalekeza okhala ndi Morse code anali mtundu wa AM. Ndizomwe timatcha on-off keying (OOK) kapena amplitude-shift keying (ASK) lero.

Ngakhale AM ​​ndi yoyamba komanso yakale kwambiri, ikadalipo m'njira zambiri kuposa momwe mungaganizire. AM ndiyosavuta, yotsika mtengo, komanso yothandiza modabwitsa. Ngakhale kufunikira kwa data yothamanga kwambiri kwatifikitsa ku orthogonal frequency-division multiplexing (OFDM) ngati njira yosinthira mowoneka bwino kwambiri, AM ikukhudzidwabe ndi mawonekedwe a quadrature amplitude modulation (QAM).

Ndi chiyani chinandipangitsa ine kuganizira za AM? M'nyengo yozizira yamkuntho ya miyezi iwiri kapena kuposerapo yapitayo, ndinapeza zambiri zanyengo yanga komanso zambiri zadzidzidzi kuchokera kumawayilesi am'deralo a AM. Makamaka kuchokera ku WOAI, siteshoni ya 50-kW yomwe yakhalapo kwa zaka zambiri. Ndikukayika kuti anali akutulutsa 50 kW panthawi yamagetsi, koma anali mlengalenga panthawi yonse ya nyengo. Masiteshoni ambiri a AM anali akugwira ntchito ndi mphamvu zosunga zobwezeretsera. Wodalirika komanso wotonthoza.

Pali malo opitilira 6,000 AM ku US masiku ano. Ndipo akadali ndi omvera ambiri, makamaka anthu am'deralo omwe amafuna kudziwa zanyengo, kuchuluka kwa magalimoto, komanso nkhani zatsopano. Ambiri amamvetserabe m’magalimoto awo kapena m’magalimoto. Pali makanema osiyanasiyana olankhulirana ndipo mutha kumvabe masewera a baseball kapena mpira pa AM. Zosankha zanyimbo zachepa, popeza nthawi zambiri amasamukira ku FM. Komabe, pali malo ena oyimba nyimbo za dziko ndi Tejano pa AM. Zonse zimadalira omvera akumaloko, omwe ali osiyanasiyana.

Wailesi ya AM imawulutsa mumayendedwe a 10-kHz otakata pakati pa 530 ndi 1710 kHz. Masiteshoni onse amagwiritsa ntchito nsanja, kotero polarization imayima. Masana, kufalitsa kumakhala ndi mafunde apansi panthaka pafupifupi ma kilomita 100. Nthawi zambiri, zimatengera mphamvu yamagetsi, nthawi zambiri 5 kW kapena 1 kW. Palibe masiteshoni ambiri a 50-kW omwe alipo, koma mawonekedwe awo ndi otalikirapo.

Usiku, ndithudi, kufalitsa kumasintha pamene zigawo za ionized zikusintha ndikupanga zizindikiro kuyenda kutali kwambiri chifukwa cha kuthekera kwawo kusinthidwa ndi zigawo zapamwamba za ion kuti apange ma hop angapo pamtunda wa makilomita chikwi kapena kuposerapo. Ngati muli ndi wailesi ya AM yabwino komanso mlongoti wautali mutha kumvera ma wayilesi padziko lonse lapansi usiku.

AM ndiyenso kusintha kwakukulu kwa wayilesi yaifupi, yomwe mutha kuyimva padziko lonse lapansi kuyambira 5 mpaka 30 MHz. Akadali amodzi mwa magwero akulu azidziwitso kumayiko ambiri adziko lachitatu. Kumvetsera pang'onopang'ono kumakhalanso kotchuka.

Kupatula kuwulutsa, AM imagwiritsidwabe ntchito pati? Wailesi ya Ham ikugwiritsabe ntchito AM; osati mu mawonekedwe apamwamba apamwamba, koma ngati single sideband (SSB). SSB ndi AM yokhala ndi chonyamulira choponderezedwa ndipo gulu limodzi lakumbali limasefedwa, ndikusiya mawu ang'onoang'ono a 2,800-Hz. Imagwiritsidwa ntchito kwambiri komanso yothandiza kwambiri, makamaka m'magulu a ham kuchokera ku 3 mpaka 30 MHz. Asitikali ndi ma wayilesi ena apanyanja akupitilizabe kugwiritsa ntchito mtundu wina wa SSB, nawonso.

Koma dikirani, si zokhazo. AM ikupezekabe mumawayilesi a Citizen's Band. Plain-old AM imakhalabe mukusakaniza, monganso SSB. Kuphatikiza apo, AM ndiye njira yayikulu yosinthira wailesi ya ndege yomwe imagwiritsidwa ntchito pakati pa ndege ndi nsanja. Mawayilesi awa amagwira ntchito mu gulu la 118- mpaka 135-MHz. Chifukwa chiyani AM? Sindinaganizirepo izi, koma zimagwira ntchito bwino.

Pomaliza, AM akadali nafe mu mawonekedwe a QAM, kuphatikiza kwa gawo ndi matalikidwe osinthika. Makanema ambiri a OFDM amagwiritsa ntchito mtundu umodzi wa QAM kuti apeze ma data apamwamba omwe angapereke.

Komabe, AM sinafabe, ndipo ikuwoneka kuti ikukalamba Mokulira.

Kodi AM Transmitter ndi chiyani?

Ma transmitter omwe amatumiza ma siginecha a AM amadziwika kuti ma transmitters a AM, amadziwikanso kuti AM radio transmitter kapena AM broadcast transmitter, chifukwa amagwiritsidwa ntchito kutumiza ma wayilesi kuchokera mbali imodzi kupita kwina.

Ma transmitterswa amagwiritsidwa ntchito m'mabandi apakati (MW) ndi ma frequency afupiafupi (SW) pakuwulutsa kwa AM.

Gulu la MW lili ndi ma frequency pakati pa 550 KHz ndi 1650 KHz, ndipo gulu la SW lili ndi ma frequency kuyambira 3 MHz mpaka 30 MHz. Mitundu iwiri ya ma transmitters a AM omwe amagwiritsidwa ntchito kutengera mphamvu zawo zotumizira ndi:

• Mulingo Wapamwamba
• Mulingo Wotsika

Ma transmitters apamwamba amagwiritsa ntchito kusinthasintha kwapamwamba, ndipo ma transmitter otsika amagwiritsa ntchito kusinthasintha kwapang'onopang'ono. Kusankha pakati pa ma module awiriwa kumadalira mphamvu yotumizira ya AM transmitter.

M'ma transmitters owulutsa, pomwe mphamvu yotumizira ingakhale ya dongosolo la kilowatts, kusinthasintha kwapamwamba kumagwiritsidwa ntchito. M'ma transmitter amphamvu otsika, pomwe ma watt ochepa okha amafunikira mphamvu zotumizira, kusinthasintha kwapang'onopang'ono kumagwiritsidwa ntchito..

Ma Transmitters apamwamba komanso otsika

Pansipa pali chithunzi chojambulidwa cha ma transmitters apamwamba komanso otsika. Kusiyana kwakukulu pakati pa ma transmitters awiriwa ndikukulitsa mphamvu kwa chonyamulira ndi ma modulating siginecha.

Chithunzi (a) chikuwonetsa chojambula chamtundu wapamwamba wa AM transmitter.

Chithunzi (a) chajambulidwa kuti chitumize mawu. Pakutumiza kwapamwamba, mphamvu za chonyamulira ndi ma modulating siginecha zimakulitsidwa musanazigwiritse ntchito pagawo la modulator, monga zikuwonekera pachithunzi (a). Pakusinthika kwapang'onopang'ono, mphamvu zazizindikiro ziwiri zolowera pagawo la modulator sizimakulitsidwa. Mphamvu yotumizira yofunikira imapezeka kuchokera kugawo lomaliza la transmitter, kalasi C mphamvu amplifier.

Magawo osiyanasiyana a chithunzi (a) ndi:

• Chonyamulira oscillator
• Buffer amplifier
• Kuchulukitsa pafupipafupi
• Mkuzamawu mphamvu
• Audio unyolo
• Modulated class C mphamvu amplifier

Carrier Oscillator

Chonyamulira oscillator chimapanga chizindikiro chonyamulira, chomwe chili mumtundu wa RF. Mafupipafupi a chonyamulira nthawi zonse amakhala okwera kwambiri. Chifukwa ndizovuta kwambiri kupanga ma frequency apamwamba ndi kukhazikika kwafupipafupi, chonyamulira oscillator imapanga kangapo kakang'ono ndi ma frequency ofunikira onyamula.

Izi sub angapo pafupipafupi ndi kuchulukitsidwa ndi pafupipafupi multiplier siteji kupeza chofunika chonyamulira pafupipafupi.

Komanso, kristalo oscillator angagwiritsidwe ntchito siteji iyi kupanga otsika pafupipafupi chonyamulira ndi bwino pafupipafupi bata. The pafupipafupi multiplier siteji ndiye kumawonjezera pafupipafupi chonyamulira kwa mtengo wake chofunika.

Buffer Amplifier

Cholinga cha buffer amplifier ndi magawo awiri. Izo poyamba likugwirizana linanena bungwe impedance wa chonyamulira oscillator ndi athandizira impedance wa pafupipafupi multiplier, gawo lotsatira la chonyamulira oscillator. Kenako amalekanitsa chonyamulira oscillator ndi pafupipafupi multiplier.

Izi zimafunika kuti wochulukitsa asakoke mphamvu yayikulu kuchokera ku chonyamulira oscillator. Izi zikachitika, mafupipafupi a oscillator chonyamulira sangakhale okhazikika.

Frequency Multiplier

Mafupipafupi ang'onoang'ono a chizindikiro chonyamulira, chopangidwa ndi chonyamulira oscillator, tsopano akugwiritsidwa ntchito kwa ochulukitsa pafupipafupi kudzera mu buffer amplifier. Gawo ili limadziwikanso kuti jenereta ya harmonic. Kuchulukitsa pafupipafupi kumapanga ma harmonics apamwamba onyamula ma frequency oscillator. Ma frequency multiplier ndi gawo losinthidwa lomwe limatha kusinthidwa kumayendedwe ofunikira omwe ayenera kufalikira.

Amplifier Wamphamvu

Mphamvu ya chizindikiro chonyamulira imakulitsidwa mu gawo la amplifier mphamvu. Izi ndi zofunika kwambiri pa transmitter yapamwamba kwambiri. Gulu la C mphamvu amplifier limapereka mphamvu zapamwamba zamakono za siginecha yonyamula pakutulutsa kwake.

Audio Chain

Chizindikiro cha audio chomwe chiyenera kuperekedwa chimachokera ku maikolofoni, monga momwe tawonetsera pa chithunzi (a). Makina opangira ma audio amakulitsa mphamvu ya siginoyi. Kukulitsa uku ndikofunikira kuti muyendetse amplifier yamagetsi. Kenako, gulu A kapena gulu B mphamvu amplifier amakulitsa mphamvu ya siginecha zomvera.

Modulated Class C Amplifier

Ili ndiye gawo lotulutsa la chopatsira. Chizindikiro chowongolera ndi chonyamulira, pambuyo pakukulitsa mphamvu, chimagwiritsidwa ntchito pagawo losinthali. Kusinthasintha kukuchitika panthawiyi. Gulu la C amplifier limakulitsanso mphamvu ya siginecha ya AM ku mphamvu yotumizira yomwe idabwezedwanso. Chizindikirochi chimaperekedwa ku mlongoti., chomwe chimatulutsa chizindikirocho kumalo otumizira.

Ma transmitter otsika a AM omwe akuwonetsedwa pachithunzicho (b) akufanana ndi chotengera chapamwamba, kupatula kuti mphamvu za chonyamulira ndi ma audio sizimakulitsidwa. Zizindikiro ziwirizi zimagwiritsidwa ntchito mwachindunji ku modulated kalasi C mphamvu amplifier.

Kusinthasintha kumachitika pa siteji, ndipo mphamvu ya siginecha yosinthidwa imakulitsidwa kumlingo wofunikira wopatsira mphamvu. Kenako mlongoti wotumizira umatumiza chizindikiro.

Kulumikizana kwa Gawo Lotulutsa Ndi Mlongoti

Gawo lotulutsa lamagetsi amplifier la kalasi C limadyetsa siginecha ku mlongoti wotumizira.

Kusamutsa mphamvu yayikulu kuchokera pagawo lotulutsa kupita ku mlongoti ndikofunikira kuti kusokoneza kwa magawo awiriwo kufanane. Kwa izi, netiweki yofananira ndiyofunika.

Kufananiza pakati pa ziwirizi kuyenera kukhala kwabwino pama frequency onse otumizira. Monga kufananitsa kumafunikira pama frequency osiyanasiyana, ma inductors ndi ma capacitor omwe amapereka ma impedance osiyanasiyana pama frequency osiyanasiyana amagwiritsidwa ntchito pama network ofananira.

Netiweki yofananira iyenera kupangidwa pogwiritsa ntchito zida izi. Izi zikuwonetsedwa m'munsimu Chithunzi (c).

Netiweki yofananira yomwe imagwiritsidwa ntchito polumikiza gawo lotulutsa ndi mlongoti imatchedwa double π-network.

Netiweki iyi ikuwonetsedwa pachithunzi (c). Ili ndi ma inductors awiri, L1 ndi L2 ndi ma capacitors awiri, C1 ndi C2. Makhalidwe a zigawozi amasankhidwa kotero kuti kulowetsedwa kwa intaneti pakati pa 1 ndi 1 '. Zomwe zikuwonetsedwa pachithunzi (c) zimagwirizana ndi kutulutsa kwamphamvu kwa gawo lotulutsa la transmitter.

Kuphatikiza apo, kusokoneza kwa netiweki kumafananizidwa ndi kutsekeka kwa mlongoti.

Netiweki yofananira iwiri π imasefanso ma frequency osafunikira omwe amawonekera pakutulutsa kwa gawo lomaliza la transmitter.

Kutulutsa kwamagetsi amplifier a kalasi C kumatha kukhala ndi ma harmonics apamwamba, monga ma harmonics achiwiri ndi achitatu, omwe ndi osafunika kwambiri.

Kuyankha pafupipafupi kwa netiweki yofananira kumayikidwa kotero kuti ma harmonic osafunikirawa amaponderezedwa, ndipo chizindikiro chokhacho chomwe chimafunidwa chimaphatikizidwa ndi mlongoti..

Chingwe chomwe chilipo kumapeto kwa gawo lotumizira, chimatumiza mawonekedwe osinthika. M'mutu uno, tikambirane za omwe amafalitsa a AM ndi FM.

AM chopatsilira

Wotumiza wa AM amatenga mawu amawu ngati cholowetsera ndikupereka matalikidwe amtundu wa matalikidwe ku antenna ngati chotulutsa choti chifalitsidwe. Chithunzi chojambulira cha AM transmitter chikuwonetsedwa pachithunzipa.

Kugwira ntchito kwa AM transmitter kungafotokozedwe motere: 

• Chizindikiro chomvera kuchokera pakulankhula kwa maikolofoni chimatumizidwa kwa pre-amplifier, yomwe imathandizira kuchuluka kwa chizindikirocho.
• RF oscillator imapanga chonyamulira.
• Modulating komanso chonyamulira chimatumizidwa kwa AM modulator.
• Mphamvu yamagetsi imagwiritsa ntchito kukulitsa mphamvu yamafunde AM. Mafunde awa pamapeto pake amapatsira tinyanga kuti tidziwitse.

FM Kutumiza

Wotumiza wa FM ndiye gawo lonse, lomwe limatenga mawu amawu ngati cholowetsera ndikupereka funde la FM ku antenna ngati chotulukapo choti chifalitsidwe. Chithunzi chojambulira cha transmitter ya FM chikuwonetsedwa pachithunzipa.

Kugwira ntchito kwa ma transmitter a FM kungafotokozedwe motere:

• Chizindikiro chomvera kuchokera pakulankhula kwa maikolofoni chimatumizidwa kwa pre-amplifier, yomwe imathandizira kuchuluka kwa chizindikirocho.
• Chizindikirochi chimaperekedwa kwa fyuluta yayikulu, yomwe imagwira ntchito ngati njira yolimbikitsira kuti isungunule phokoso ndikusintha chizindikirocho mpaka phokoso.
• Chizindikirochi chimadutsidwanso kudera la FM modulator.
• Dongosolo la oscillator limapanga chonyamulira chapafupipafupi, chomwe chimatumizidwa kwa modulator pamodzi ndi chizindikiro chosinthira.
• Magawo angapo obwereza pafupipafupi amagwiritsidwa ntchito kukulitsa magwiridwe antchito. Ngakhale pamenepo, mphamvu ya chizindikirocho siyokwanira kutumiza. Chifukwa chake, mphamvu yama RF yamagetsi imagwiritsidwa ntchito kumapeto kuti iwonjezere mphamvu yama siginolo. Izi zotulutsa za FM pamapeto pake zimaperekedwa ku antenna kuti zikafalitsidwe.

Kuyerekeza kwa AM ndi Zizindikiro za FM

Makina onse a AM ndi FM amagwiritsidwa ntchito pazamalonda komanso osachita malonda. Monga kuwulutsa pawailesi komanso kuwulutsa pa TV. Dongosolo lililonse lili ndi zabwino zake komanso zoyipa zake. Mukugwiritsa Ntchito Mwapadera, kachitidwe ka AM kumatha kukhala koyenera kuposa kachitidwe ka FM. Choncho ziwirizi ndi zofunika mofanana kuchokera ku kagwiritsidwe ntchito kawonedwe.

Ubwino wamakina a FM pa AM Systems

Kukula kwa mafunde a FM kumakhalabe kosasintha. Izi zimapereka okonza dongosolo mwayi wochotsa phokoso kuchokera ku chizindikiro cholandiridwa. Izi zimachitika mwa olandila ma FM pogwiritsa ntchito gawo la amplitude limiter kuti phokoso lomwe lili pamwamba pa matalikidwe oletsa litsekedwe. Chifukwa chake, dongosolo la FM limatengedwa ngati chitetezo chamkokomo. Izi sizingatheke m'makina a AM chifukwa chizindikiro cha baseband chimanyamulidwa ndi kusiyanasiyana kwa matalikidwe ake ndipo envelopu ya chizindikiro cha AM sichingasinthidwe.

- Mphamvu zambiri mu siginecha ya FM zimanyamulidwa ndi magulu am'mbali. Pazinthu zapamwamba za index modulation, mc, gawo lalikulu la mphamvu zonse lili ndi magulu am'mbali, ndipo chizindikiro chonyamulira chimakhala ndi mphamvu zochepa. Mosiyana ndi izi, mu dongosolo la AM, gawo limodzi mwa magawo atatu a mphamvu zonse zimanyamulidwa ndi magulu am'mbali ndipo magawo awiri pa atatu a mphamvu zonse zimatayika ngati mphamvu zonyamulira.

- M'makina a FM, mphamvu ya siginecha yopatsirana imadalira kukula kwa chizindikiro chonyamulira chosasunthika, chifukwa chake chimakhala chokhazikika. Mosiyana ndi izi, mumakina a AM, mphamvu zimatengera ma modulation index ma. Mphamvu zovomerezeka kwambiri m'machitidwe a AM ndi 100 peresenti pamene ma ndi umodzi. Kuletsa koteroko sikugwira ntchito ngati machitidwe a FM. Izi zili choncho chifukwa mphamvu zonse mumayendedwe a FM sizidalira modulation index, mf ndi frequency deviation fd. Chifukwa chake, kugwiritsa ntchito mphamvu ndikwabwino pamakina a FM.

Mu dongosolo la AM, njira yokhayo yochepetsera phokoso ndikuwonjezera mphamvu yotumizira chizindikiro. Kuchita izi kumawonjezera mtengo wadongosolo la AM. Mumakina a FM, mutha kuwonjezera kupotoza pafupipafupi mu siginecha yonyamula kuti muchepetse phokoso. ngati kupatuka kwafupipafupi kuli kwakukulu, ndiye kuti kusiyanasiyana kofananira mu matalikidwe a siginecha ya baseband kumatha kubwezedwa mosavuta. ngati kupatuka kwafupipafupi kuli kochepa, phokoso 'limatha kuphimba kusiyana kumeneku ndipo kusinthasintha kwafupipafupi sikungatanthauzidwe kusinthasintha kwake kofanana. Chifukwa chake, pakuwonjezereka kwapang'onopang'ono mu siginecha ya FM, phokoso limatha kuchepetsa. Palibe njira mu AM system yochepetsera phokoso ndi njira iliyonse, kupatula kuwonjezera mphamvu zake zotumizira.

Mu chikwangwani cha FM, njira zoyandikana ndi FM zimalekanitsidwa ndi magulu a alonda. Mumakina a FM mulibe kutumizira ma siginecha kudzera mu mlengalenga kapena gulu la alonda. Chifukwa chake, palibe kusokoneza kulikonse kwa mayendedwe oyandikana nawo a FM. Komabe, mu dongosolo la AM, palibe gulu lachitetezo lomwe limaperekedwa pakati pa njira ziwiri zoyandikana. Chifukwa chake, nthawi zonse pamakhala kusokoneza kwa wayilesi ya AM pokhapokha ngati siginecha yolandilidwayo ili yolimba mokwanira kuletsa chizindikiro cha mayendedwe oyandikana nawo.

Zoyipa zamakina a FM pamakina a AM

Pali chiwerengero chosatha chamagulu am'mbali mu siginecha ya FM ndipo chifukwa chake bandwidth yamalingaliro amtundu wa FM ndi yopanda malire. Mayendedwe amtundu wa FM amachepetsedwa ndiulamuliro wa Carson, koma akadali okwera kwambiri, makamaka mu WBFM. M'makina a AM, bandwidth ndi kawiri kokha kusinthasintha kwafupipafupi, komwe kuli kochepa kwambiri kuposa kwa WBFN. Izi zimapangitsa makina a FM kukhala okwera mtengo kuposa AM.

Zipangizo zamakina a FM ndizovuta kwambiri kuposa machitidwe a AM chifukwa cha mayendedwe ovuta a machitidwe a FM; Ichi ndi chifukwa china chomwe makina a FM ndi okwera mtengo AM machitidwe.

Malo olandirira ma FM ndi ocheperako kuposa ma AM motero mawayilesi a FM amangopezeka m'matawuni pomwe ma wayilesi a AM amatha kulandilidwa kulikonse padziko lapansi. Dongosolo la FM limatumiza ma siginecha kudzera pamzere wowonekera, pomwe mtunda pakati pa kutumizira ndi kulandira mlongoti suyenera kukhala wambiri. mu AM system ma siginecha a masiteshoni amfupi a band amafalitsidwa kudzera mumlengalenga omwe amawonetsa mafunde a wailesi kudera lalikulu.

Chifukwa chakugwiritsa ntchito mosiyanasiyana, AM Transmitter imagawidwa kwambiri kukhala anthu wamba AM Transmitter (DIY ndi ma transmitter otsika a AM) ndi AM Transmitter yamalonda (yawayilesi yankhondo kapena wayilesi yapadziko lonse ya AM).

Commerce AM Transmitter ndi imodzi mwazinthu zomwe zimayimilira kwambiri pagawo la RF. 

Ma transmitter amtundu wawayilesi amatha kugwiritsa ntchito tinyanga zake zazikulu za AM (guyed mast, ndi zina zambiri) kuulutsa ma siginecha padziko lonse lapansi. 

Chifukwa AM siyingaletsedwe mosavuta, ma transmitter a AM nthawi zambiri amagwiritsidwa ntchito ngati zabodza zandale kapena zokopa zankhondo pakati pa dzikolo.

Mofanana ndi chowulutsira cha FM, chowulutsira cha AM chimapangidwanso ndi mphamvu zosiyanasiyana. 

Kutengera chitsanzo cha FMUSER, mndandanda wawo wamalonda wa AM transmitter umaphatikizapo 1KW AM transmitter, 5KW AM transmitter, 10kW AM transmitter, 25kW AM transmitter, 50kW AM transmitter, 100kW AM transmitter, ndi 200kW AM transmitter. 

Ma transmitters awa amapangidwa ndi kabati yolimba yopangidwa ndi gilt, ndipo ali ndi makina owongolera akutali a AUI ndi kapangidwe kazinthu zofananira, zomwe zimathandizira kutulutsa kwazizindikiro zapamwamba za AM.

Komabe, mosiyana ndi kupanga wayilesi ya FM, kumanga wayilesi ya AM ​​transmitter ndikokwera mtengo. 

Kwa owulutsa, kuyambitsa siteshoni yatsopano ya AM ndikokwera mtengo, kuphatikiza:

- Mtengo wogula ndi kunyamula zida za wailesi ya AM. 

- Mtengo wa kubwereketsa antchito ndi kukhazikitsa zida.

- Mtengo wogwiritsa ntchito zilolezo zowulutsa za AM.

- Ndi zina. 

Chifukwa chake, pamawayilesi amtundu uliwonse kapena asitikali othandizira odalirika okhala ndi njira zoyimitsa kamodzi amafunikira mwachangu pazida zotsatirazi za AM:

Mphamvu yayikulu ya AM Transmitter (mazana masauzande amphamvu zotulutsa monga 100KW kapena 200KW)

AM Broadcast antenna system (Mlongoti wa AM ndi nsanja ya wailesi, zowonjezera za mlongoti, mizere yolumikizira yolimba, ndi zina zotero)

Zida zoyeserera za AM ndi zida zothandizira. 

Etc.

Ponena za otsatsa ena, njira yotsika mtengo ndiyokongola kwambiri, mwachitsanzo:

- Gulani AM Transmitter ndi mphamvu yotsika (monga 1kW AM Transmitter)

- Gulani ma transmitter a AM Broadcast omwe amagwiritsidwa ntchito

- Kubwereka nsanja ya wailesi ya AM yomwe ilipo kale

- Ndi zina.

Monga wopanga zida zonse zapa wayilesi ya AM, FMUSER ikuthandizani kupanga yankho labwino kwambiri kuyambira kumutu mpaka kumapazi malinga ndi bajeti yanu, mutha kupeza zida zapa wayilesi ya AM kuchokera ku state high power AM transmitter kupita ku AM test load ndi zida zina. , Dinani apa kuti mudziwe zambiri za mayankho a wailesi ya FMUSER AM.

Ma transmitter wamba AM ndiwofala kwambiri kuposa ma transmitter a AM chifukwa ali ndi mtengo wotsika.

Atha kugawidwa makamaka kukhala DIY AM transmitter ndi low AM transmitter. 

Kwa ma transmitters a DIY AM, ena mwa okonda wailesi nthawi zambiri amagwiritsa ntchito bolodi yosavuta kuwotcherera zinthu monga audio in, antenna, transformer, oscillator, chingwe chamagetsi ndi mzere wapansi.

Chifukwa cha ntchito yake yosavuta, DIY AM transmitter imatha kukhala ndi theka la kanjedza kokha. 

Ichi ndichifukwa chake ma transmitter amtundu wa AM amangotengera madola khumi ndi awiri okha, kapena atha kupangidwa kwaulere. Mutha kutsata kanema wophunzirira pa intaneti ku DIY imodzi.

Ma transmitters otsika a AM amagulitsidwa $100. Nthawi zambiri amakhala ngati rack kapena amawonekera mubokosi lachitsulo laling'ono lamakona anayi. Ma transmitter awa ndi ovuta kwambiri kuposa ma transmitters a DIY AM ndipo ali ndi othandizira ang'onoang'ono.