Amateur Radio umyalezo: iimpawu

Amateur radio antenna abafumana amakhulu amawaka iisignali zerediyo ngaxeshanye. esasidla yabo inokwahluka ngokuxhomekeke ukosuleleka kwi elide, eliphakathi,, amaza Ultra mfutshane mfutshane and bands nomabonakude. Phakathi kwabo asebenza engahlawulwayo, kukarhulumente, zaselwandle zorhwebo kunye nezinye izikhululo. Le ngezantya ezi maza anikwe kwigalelo receiver eriyali, asusela ngaphantsi kwe-1 MV ukuya millivolts ezininzi. nabo radio engahlawulwayo kwenzeka kwinqanaba le microvolts ezimbalwa. Ukuqeshwa engahlawulwayo receiver ezimbini: ukhetho, yokukhulisa, kunye demodulation yomqondiso serediyo, zikhusela bonke abanye. balwamkele radio engahlawulwayo ziyafumaneka nokuba zodwa okanye njengenxalenye transceiver.

Eyona engundoqo amacandelo yomfumani

Ham balwamkele radio kufuneka akwazi ukufumana iimpawu buthathaka kakhulu, ukuba abahlule ingxolo kakhulu kunye namandla izikhululo, zisoloko ekhona emoyeni. Ngoko ukugcinwa kunye demodulation zabo kufuna uzinzo eyaneleyo. ekuqhutywe ngayo xa iyonke (kunye nexabiso) le ixhomekeke kwi inovakalelo, selectivity kunye nozinzo. Kukho ezinye izinto ezinxulumene nokwenziwa ifowuni. Ezi ziquka coverage namatyeli ukufunda, Imo demodulation okanye ekufumanekeni LF, MF, HF, oonomathotholo VHF, iimfuno namandla. Nangona abanye balwamkele ahluka yi, bonke ubunzima kunye nokusebenza inkxaso 4 imisebenzi engundoqo: ukwamkelwa, selectivity, demodulation kunye nokuzala. Abanye zikwaquka ezifane ukunyusa umgangatho uphawu kumaxabiso eyamkelekileyo.

indawo yolwamkelo

Kukukwazi yomfumani yokusingatha iimpawu buthathaka eziqokelelwe yi-eriyali. Kuba irediyo, lo msebenzi osemqoka ikakhulu ezinxulumene ne uvakalelo. Imifanekiso uye aqukuqela eziliqela sufaka ezifunekayo ukwandisa amandla uphawu ukusuka microvolts ukuya volts. Ngoko ke, lo ufumana inzuzo jikelele uyakwazi ukufikelela ngumyalelo million ukuya kwenye.

Beginners hams luncedo ukwazi ukuba uvakalelo yomfumani bachatshazelwa ingxolo zombane iveliswe kwisekethe eriyali kunye nefowuni, ingakumbi igalelo kunye RF iimodyuli. Ukuba kwenzeka ngexesha iimolekyuli thermal excitation umqhubi kunye namacandelo msindo ezifana transistors kunye neetyhubhu. Ngokubanzi, ingxolo lombane frequency kuxhomekeke kwaye kwandisa kunye lobushushu kunye bandwidth.

Nayiphi langoku wengxolo iiterminal kwisamkeli eriyali ziyanyuswa kunye uphawu ezifunyenweyo. Ngoko ke, kukho umda uvakalelo yomfumani. Uninzi imifuziselo zanamhlanje ziyakwazi ukufumana 1 MV okanye ngaphantsi. iinkcukacha ezininzi ukuchaza le nxalenye microvolts ku-10 dB. Umzekelo, ukuba ethe-0.5 MV ku-10 dB kuthetha ukuba ingxolo awo eyenziwe kwisamkeli kangangama-10 dB ngezantsi umqondiso 0.5 MV. Ngamanye amazwi, izinga lengxolo umdlali malunga 0.16 MV. Naluphi uphawu ngezantsi xabiso ziyangenana kwaye abayi kuba oluvakalayo kwi kwisithethi.

Xa amaza ka 20-30 MHz yengxolo lwangaphandle (esesibhakabhakeni kunye ezenziwe ngumntu) idla na ukuphazamiseka lwangaphakathi aphezulu kakhulu. Uninzi balwamkele babe uvakalelo olwaneleyo ukuze kungonakali uphawu kule uluhlu rhoqo.

selectivity

Oku uyakwazi urhwebo ufumana ukuya uphawu efunekayo yaye ukwala okungafunekiyo. In balwamkele usebenzisa ophezulu-Q LC-lokucoca zikhukula kuphela bandwidth elimxinwa. Ngoko ke, lo bandwidth umdlali kubalulekile ukuphelisa imiyalezo ezingafunekiyo. Selectivity abaninzi DV-bathunyelwa komyalelo amakhulu eziliqela elilodwa. Oku kwanele ukususa uninzi imiyalezo zikufutshane eziya kwi-frequency yokusebenza. Zonke engahlawulwayo balwamkele radio HF kunye zibe SV kufuneka sikhethe 2500 Hz ukwamkela ilizwi engahlawulwayo. balwamkele abaninzi kunye transceiver ET / amacebo HF switchable isetyenziselwa ukubonelela kangangoko uphawu yokwamkela naluphi na uhlobo.

Demodulation, okanye ubhaqo

Le nkqubo esekungcoleni LF-candelo (isandi) ukusuka engenayo modulated isignali yenethiwekhi. KwiSekethe demodulation usebenzisa transistors okanye isibane. Ezi zimbini ziqhelekileyo detectors iintlobo ezisetyenziswa balwamkele RF, - i diode for Lw kunye MW, kunye Lw Umxhubi efanelekileyo okanye HF.

ukudlala

Inkqubo yokugqibela ukuyiguqula uphawu yokwamkela ibonakele ifidi odiyo isithethi okanye headphones. Ngokuqhelekileyo, yokukhulisa imveliso ezibuthathaka kakutsha isigaba isetyenziswe ngempumelelo eliphezulu. output msindo emanyelwayo ngoko anikwe isithethi okanye earphone ukuba zande.

Uninzi balwamkele radio engahlawulwayo sibe isithethi lwangaphakathi kunye jack yoLungiso kwimveliso. eyodwa isigaba audio msindo Simple afanelekileyo ukwenzela ukusetyenziswa headphones. Kuba isithethi kudla ngokufuna-2 okanye ezi-3-isigaba audio umsindo.

balwamkele elula

Abaphiwa yokuqala radio sisixhobo elula sapho lwaluquka isekethe oscillatory, kristallodetektora head. Baye ingathatha kwisikhululo sikanomathotholo yasekuhlaleni. Noko ke, ngathi ngembonakalo yikristale tshin akanako demodulate ngokuchanekileyo Lw amaza omoya okanye SW. Ngaphezu koko, ubuntununtunu kunye selectivity yenkqubo enjalo ayanelanga ukuba umsebenzi engahlawulwayo. Yandisa kuzo ngokongeza lo mshini odiyo ukuya kwimveliso ye tshin.

Radio yokukhulisa ngqo

Uvakalelo kunye selectivity nokuba ingaphuculwa ngokongeza izigaba omnye okanye ngaphezulu. Olu hlobo sixhobo kuthiwa receiver inzuzo ethe ngqo. '20 kunye' abaninzi SW bathunyelwa zorhwebo 30. Thina usebenzisa le nkqubo ilandelayo. Abanye kubo ibakala inzuzo 2-4 ukufumana uvakalelo ezifunwayo kunye selectivity.

ngqo conversion ethatha

Le yindlela elula nezaziwayo ngokufumana kunye HF ET. Uphawu input kondliwa a kakutsha kunye wokuphehla RF. eziliqela njalo Last phezulu (okanye ngezantsi) wokuqala ukuba abe nako ukufumana nokubetha kwentliziyo. Umzekelo, ukuba igalelo 7155,0 kHz, kwaye RF generator iqwalasele ukuba 7155,4 kHz, ngoko nokuxuba kwi kakutsha yenza isandi 400 Hz. Last uyangena eliphezulu-amandla lokucoca elimxinwa kakhulu odiyo. Selectivity kule hlobo yomfumani kufikelelwa nge kwiisekethe LC-oscillatory kunye kakutsha isandi phambi filter phakathi kakutsha kunye msindo odiyo.

superheterodyne

Ziphuhliswe 1930 ukwenzela ukuphelisa zonke iingxaki abajongene ziintlobo ezindala balwamkele radio engahlawulwayo. Namhlanje superheterodyne yomfumani kusetyenziswa phantse zonke iintlobo zeenkonzo erediyo, kubandakanywa andilociko irediyo, ezorhwebo, kunye namandla awo namatyeli kwezwi kunye nomabonakude. Umahluko ephambili abaphiwa ngqo-yokukhulisa ukuyiguqula uphawu RF efikayo eliphakathi (UKUBA).

RF sesimangalo

Ziquka LC-iziphaluka ukuba zinikeza selectivity kunye yokukhulisa limited qho ezinqwenelekayo. Lo mshini RF kwakhona ziyanceda ezimbini ezongezelelweyo kwindawo receiver superheterodyne. Okokuqala, oko Ozahlulayo izigaba lokuxhuba wesekethe oscillator lendawo-eriyali. Kuba irediyo, ukugqithisela silele yokuba iziganeko okuncitshiswe olungafunekiyo ogama frequency kabini phezulu oyifunayo.

generator

Afunwayo ukwenza i uphawu sinusoidal kunye namandla awo rhoqo, ogama rhoqo yohlukile yenethiwekhi lokwenza igalelo ixabiso elilingana IF. Generator kudala intlokoma, anokuba frequency mhlawumbi ngaphezulu okanye ngezantsi yenethiwekhi. Oku kukhetha emiselwe iimfuno bandwidth yaye RF nokuqwalasela. Uninzi iindibano ezinjalo NE-balwamkele kwaye aphantsi engahlawulwayo band VHF-ngumamkeli odala amaza igalelo ngaphezu yenethiwekhi.

wokuxova

Injongo yale yunithi ukuyiguqula amaza uphawu yenethiwekhi engenayo ukuba frequency UKUBA-umsindo. Wokuxova iimveliso 4 uphawu lwe output eziphambili 2 igalelo: f _1, f _2, f ₁ + f _2, f ₁ -f _2. Xa i-superheterodyne lisetyenziswa kuphela mhlawumbi bawadibanise okanye umahluko. Abanye inokubangela uphazamiseko ukuba amanyathelo afanelekileyo.

UKUBA sesimangalo

Iimpawu ze-UKUBA wokukhulisa kwi i-superheterodyne zichazwe kakuhle ngokubhekiselele inzuzo (CG) kunye selectivity. Ngokubanzi, aba parameters egqitywe UKUBA umsindo. Le selectivity ye UKUBA wokukhulisa izakulingana nobubanzi angenayo modulated umqondiso RF band. Ukuba kunjalo, ngoko nayiphi rhoqo esecaleni kudale ukuphazamiseka Marathon kunye. Kwelinye icala, ukuba selectivity mxinwa kakhulu, ezinye bands osecaleni shwaka. Oku kukhokelela kwilahleko inkcazelo isandi kwesithethi okanye headphones.

I elilelona short-receiver bandwidth yi 2300-2500 Hz. Nangona ezinye icala bands eliphezulu ezinxulumene iimpawu zentetho ngaphaya 2500 Hz, nokuncipha kwabo kuba ayithethi kakhulu kuchaphazela isandi okanye iinkcukacha sigqithiswe umqhubi. 400-500 Hz selectivity elaneleyo ET. Le band emxinwa kunceda ukuba ukwala naluphi uphawu yobuninzi ezikufutshane, leyo kusengaphazamisana ulwamkelo. Xa oonomathotholo engahlawulwayo, ixabiso apho ngentla zisetyenziswa ezimbini okanye ngaphezulu ndachithelwa UKUBA okhulisa kunye lokucoca ngomatshini kakhulu crystalline okanye ngaphambi. Ngesi lungiselelo, phakathi iibloko kusetyenziswa LC-iziphaluka kunye converters inverter.

Ukukhethwa amaza esiPhakathi limi kumiselwa izinto ezininzi, eziquka: selectivity ziphuculwa uphawu ingcinezelo. Kuba iibhendi zamaza ephantsi (80 no-40 m) inverter ezisetyenziswa ezininzi balwamkele mihla radio engahlawulwayo ngu 455 kHz. IF yokukhulisa uyakwazi ukunika inzuzo elihle kunye selectivity ka 400-2500 Hz.

Detectors kunye oscillators nesingqi

Bangabonwa, okanye demodulation, ichazwa njenge inkqubo division amacandelo Audio rhoqo isignali yenethiwekhi modulated. Detectors e balwamkele superheterodyne, ebizwa aphakamileyo kwakhona, kodwa Umxhubi olusezantsi udumbo.

alawule Automatic

Injongo yale unit AGC kukugcina kwinqanaba rhoqo uphawu lwe output, nangona utshintsho igalelo. amaza erediyo zandise ngokusebenzisa ionosphere, ngoko buthathaka, ngoko augmented isenzeko eyaziwa ngokuba ayaphela. Oku kukhokelela utshintsho kwinqanaba yokwamkela kwi zibuko eriyali kuluhlu olubanzi lwamaxabiso. Ekubeni uphawu ombane kulungiswa ngokomlinganiselo awo le kakutsha ezifunyenweyo, inxalenye inokusetyenziswa ukulawula inzuzo. Kuba balwamkele esebenzisa isibane okanye npn-transistors kwi iindawo owandulela tshin, ukunciphisa KU ombane ezigxekayo isicelo. Yokukhulisa ngabenzi, esebenzisa PNP-transistors kufuna ombane entle.

Ezinye balwamkele radio engahlawulwayo, ingakumbi transistor okusemandleni ukuba msindo ngolawulo inzuzo oluzenzekelayo ulawulo enkulu phezu iimpawu ifowuni. ulungiso oluzenzekelayo kunokuba constants ezahlukeneyo ixesha iintlobo ezahlukeneyo signal. Ixesha njalo limisela ixesha kolawulo emva kokupheliswa wokuguqulela. Ngokomzekelo, ngamaxesha ekhefu phakathi amabinzana HF ngumamkeli ukuze uqalise kwangoko inzuzo epheleleyo, ibangela i ingxolo ikudika oluvakalayo.

Umlinganiselo ngokwasekomeleleni uphawu

Kwezinye balwamkele, kunye transceiver sinika sisalathisi ebonisa amandla xa kuthelekiswa zosasazo. Ngokuqhelekileyo inxalenye kulungiswa yomqondiso UKUBA ukusuka kakutsha kondliwa a ngemithamo okanye milliammeter. Xa umdlali eye msindo AGC, le yunithi inokusetyenziswa ukulawula idispleyi. Uninzi izixhobo yokukala ukukala ngeeyunithi S-(1 ukuya ku-9) apho kukho malunga nama-6 dB utshintsho ngamandla uphawu ezifunyenweyo. Ukufundwa avareji okanye S-9 osetyenziswa ukubonisa inqanaba 50 MV. Isiqingatha eliphezulu kwesikali-S manzi lihlelwe kwi decibels ngentla S-9, ngokokuqhelekileyo ukuya ku-60 dB. Oku kuthetha ukuba amandla uphawu efunyenwe kwi-60 dB ngaphezu 50 UV kwaye ilingana no 50 MV.

Esi salathisi echanileyo kunqabile, ngokuba umsebenzi wakhe iphenjelelwa yimiba ezininzi. Nangona kunjalo, kubalulekile kakhulu ekumiseleni ngobunzulu isalamane iimpawu ezingenayo, kwakunye njengokuhlola okanye kwakumiselwa receiver. Xa transceiver ezininzi Isalathisi yenzelwe ukubonisa ubume iimpawu sixhobo, ezifana RF wokukhulisa yangoku yokugqibela kunye namandla RF output.

Ukungenela Imida

Beginners hams luncedo ukwazi ukuba umamkeli ezinokuba ziya kukhathaza ubunzima omoya ngenxa yezi zinto zintathu: ingxolo ngaphakathi nangaphandle kunye nemiqondiso ziphazamisa. ukuphazamiseka RF yangaphandle, ingakumbi ngezantsi 20 MHz, ngaphezulu kakhulu kunalawo zangaphakathi. Kuphela phezulu iindawo ngumamkeli zenza usongo Imiqondiso siswele kakhulu. Uninzi iingxolo eyenziwe kwibhloko yokuqala, njengoko lo mshini radio-rhoqo, kwaye Umxhubi ayo. zininzi iinzame ezenziweyo ukunciphisa ingxolo receiver yangaphakathi ukuya kwinqanaba ubuncinane. Ngenxa yoko, kwakukho iziphaluka ingxolo ephantsi amacandelo.

ukuphazamiseka lwangaphandle kungabangela iingxaki ulwamkelo lweesignali amandla ngenxa yezizathu ezibini. Okokuqala, ingxolo ebanjwe yi-eriyali, uyakwazi tifihla zosasazo. Ukuba yokugqibela sisondele okanye ngaphantsi kwenqanaba ingxolo engenayo, ulwamkelo cishe kungenakwenzeka. Abanye abasebenzi abanamava uyakwazi ukufumana usasazo kwiMpuma Ekude, nangona ukuphazamiseka phezulu, kodwa imiqondiso ilizwi kunye nezinye engahlawulwayo kwezi meko akucaci.