Ukusetyenziswa kwe-21.4MHz Filter kwi-Walkie{1}}Talkie Field

Ukusetyenziswa kwe-21.4MHz Filter kwi-Walkie{1}}Talkie Field

Isihluzo se-21.4MHz siqhele ukusetyenziswa njenge-intermediate frequency (IF) filter kwi-walkie{1}}abamkeli be-talkie, kwaye ukusebenza kwayo kumisela ngokuthe ngqo izalathi ezibini ezingundoqo ze-walkie{2}}iintetho: ukukhetha kunye novakalelo.

Siza kucacisa nzulu kule miba ilandelayo:

1. Yintoni i-"Intermediate Frequency" ye-Walkie{1}}Talkie?

Ukuphumeza ukusebenza kakuhle, i-walkie{0}}talkies (kunye nabanye abamkeli be-superheterodyne) abakhulisi ngokuthe ngqo kwaye banciphise imiqondiso yerediyo efunyenweyo (RF) (umz., 400-470MHz). Endaweni yoko, bamkela la manyathelo alandelayo: ① Ukuxuba: Isignali ye-RF efunyenweyo ye-frequency ephezulu ixutywa kunye nomqondiso oveliswe yi-oscillator yendawo.② IsiVelisi se-Intermediate Frequency: Emva kokuxubana, isignali entsha enefrikhwensi esisigxina iyaveliswa, eyi-frequency ephakathi.

Inzuzo yesakhiwo se-"superheterodyne" kukuba ininzi yokuzuza kunye nokukhetha (ikhono lokucoca ukuphazamiseka kwesiteshi esikufutshane) kufezekiswa ngeli candelo elisisigxina le-IF, okwenza uyilo lwesiphaluka luzinzile kwaye lusebenze ngokugqwesileyo.

2. Kutheni 21.4MHz?

I-21.4MHz ngumgangatho oqhelekileyo we-IF oqhelekileyo kwiibhendi zeVHF/UHF (kubandakanywa neebhendi ezisetyenziswa zii-walkie{1}}talkies). Izizathu zayo zembali kunye nezobugcisa ziquka:

Isixokelelwano semizi-mveliso esikhulileyo: Kwi-21.4MHz rhoqo, kukho inani elikhulu lezihluzi ezivuthiweyo, ezizinzileyo, neziphantsi{1}}, ii-amplifiers, kunye nezinto ezinxulumeneyo ezikhoyo.

Ibhalansi phakathi kokusebenza kunye neendleko: Le ngqungquthela iphezulu ngokwaneleyo ukucinezela ngokufanelekileyo ukuphazamiseka komfanekiso (ukuphazamiseka okuqhelekileyo kokufumana); kwangaxeshanye, iphantsi ngokwaneleyo ukuququzelela uyilo kunye nokwenziwa kwezihluzo eziphezulu-Q (umgangatho wezinto) (ezifana nezihluzo zekristale kunye nezihluzo zeseramikhi).

Ilifa lembali: Eli xesha lisetyenziswa kushishino lonxibelelwano amashumi eminyaka, kwaye uninzi lweetshiphusi ze-talkie-eziqhelekileyo kunye nezisombululo ziyilwe malunga nale frikhwensi ephakathi.

3. Indima enguNdoqo ye-21.4MHz Isihluzi kwi-Walkie{2}}i-Talkies

Kwicandelo le-21.4MHz IF, isihluzo ngoyena "umgcini-sango". Indima yayo ibalulekile:① Phucula ukukhetha

Umsebenzi: Ukukhetha kubhekisa kubuchule bomamkeli bokwahlula isiginali efunwayo kwimiqondiso emininzi kunye nokucinezela imiqondiso yokuphazamiseka kwetshaneli ekufutshane.

Indlela esebenza ngayo: Isihluzi se-21.4MHz sinegophe lokuphendula lamatyeli aphakamileyo (lidla ngokufana "nodonga lwezitena"). Ivumela kuphela isahlulo sesignali kunye ne-21.4MHz njengeziko kunye ne-bandwidth echanekileyo kakhulu ukuba idlule (umzekelo, ± 6.25kHz, ± 7.5kHz, ± 12.5kHz esetyenziswa ngokuqhelekileyo kwii-walkie - zentetho, ezihambelana nezithuba zesiteshi ezahlukeneyo).

Isiphumo esisebenzayo: Xa izikhululo zikanomathotholo ezibini ezinamaza asondele kakhulu zisasaza ngaxeshanye, i-walkie{0}}talkie exhotyiswe{1}}nokusebenza okuphezulu 21.4MHz isihluzo inokusiva ngokucacileyo isandi sesikhululo sikanomathotholo ekujoliswe kuso, ngelixa icinezela ngokufanelekileyo umqondiso wesinye isitishi esikufuphi ukunqanda ukungqubana. Ngaphandle kwesi sihluzo okanye ngesihluzo esisebenza kakubi, uya kuva ingxolo ye "channel crosstalk".

② Phucula uvakalelo

Umsebenzi: Uvakalelo lubhekiselele kubuchule bomamkeli bokufumana imiqondiso ebuthathaka.

Isebenza njani: Phambi kokukhulisa isignali ye-IF, isihluzo sisetyenziselwa ukuhluza ngaphandle-kwi{1}}ingxolo yebhendi kunye nokuphazamiseka kuqala. Ngale ndlela, ulwandiso oluphambili luphawu "lucocekileyo" oluluncedo ngokwalo. Ukuba ulwandiso lwenziwa ngaphandle kohluzo, ngaphandle{4}kwe{5}}kwingxolo yebhendi nayo iyakwandiswa, ngaloo ndlela kurhaxwa umqondiso obuthathaka osebenzayo.

Isiphumo esisebenzayo: Ivumela i-walkie{0}}talkie yakho ukugcina unxibelelwano oluqondakalayo nakwimigama emide okanye ngeempawu ezibuthathaka.

4. Iintlobo zeeFilters ze-21.4MHz

Kwi-walkie-talkies, izihluzo eziqhelekileyo ze-21.4MHz ziquka ikakhulu ezi ndidi zilandelayo:

Isihluzo seCeramic:

Iimpawu: Iindleko eziphantsi, ubungakanani obuncinci, ukuthembeka okuphezulu, kwaye akukho luhlengahlengiso olufunekayo.

Usetyenziso: Isetyenziswa kakhulu phakathi-ukuya{1}}phantsi-ekugqibeleni{3}}iintetho zokuhamba, kwaye ukusebenza kwayo kwanele ukuhlangabezana nezona mfuno zesiqhelo. I-bandwidth yayo kunye ne-shape factor (isalathisi sokulinganisa ubunzulu bomda wokucoca) ihlala imbi kancinci kunezihluzo zekristale kodwa zingcono kakhulu kunezihluzo zeLC.

Isihluzo seCrystal:

Iimpawu: Inexabiso eliphezulu kakhulu le-Q, ngoko ke ukukhetha kugqwesile, kwaye imeko yemilo isondele kakhulu kwimeko efanelekileyo.

Usetyenziso: Idla ngokusetyenziswa-kwiintetho eziphakamileyo zobuchule-okanye amaxesha afuna ukuchasana{2}}nophazamiseko oluphezulu kakhulu. Iindleko ziphezulu kunezo zihluzo ze-ceramic.