suparahetarodaain sangraahi

pratham vishvayuddh ke dauraan major edavin Armstrong naamak vaigyaanik ne saral sangraahi mein apekshit sudhaar kar aisi sangraahi vyavastha ko janm diya jismein kisi bhi aavrutti ke sanket ko kisi samay sugamata se grahan kiya ja sakta hai. yeh vyavastha vastut: aadhunik lokapriya radio sangraahi seton ki janak hai.

entena se aanevaale radio aavrutti ke sanketon ko sarvapratham ek mishran-pad (mixer stage) se hokar gujaara jaata hai, jahaaain usi kshan upayukt aavrutti ka ek anya radio sanket bhi pravisht karaaya jaata hai. yeh doosra sanket ek anya sthaaneeya kanpitr (local oscillator) mein utpann kiya jaata hai. mishran pad mein donon sanketon ke sanyojan se vispand-siddhaant (beat theory) dvaara ek nimn aavrutti ka sanket utpann hota hai, jo donon aavruttiyon ka antar hota hai. mishran-pad ke aage ka sampoorn paripth isi aavrutti ke liye samasvarit hota hai. yeh aavrutti maadhya aavrutti (intermediate frequency, ya i. f.) kahalaati hai. is ksheen aavrutti ko ek radio-aavrutti pravardhak (r. f. amplifier) dvaara pradarshit kar, tatha vimaadulak (demodulator) dvaara sanshodhit kar, sansoochak vaalv dvaara shravyaavrutti mein parint kiya jaata hai. aage is shravya aavrutti ka pravardhit kar dhvani vistaarak mein preshit kar diya jaata hai.

suparaheterodaain sangraahi ka block aarekh

suparahetarodaain sangraahi ki visheshataaeain

suparahetarodaain sangraahi nimnalikhi visheshataaon ke kaaran upayogi hota hai :

  • (1) ismein radio aavrutti pravardhan, vah bhi visheshakar nimn aavruttiyon ke liye, adhik uttam evam vighnarahit utpann hota hai.
  • (2) vaanchhit aavrutti ka chayan kar sakane ki kshamata ismein paryaapt hoti hai, kyonki samasvarit paripth ko us aavruttivishesh ke liye samasvarit kiya ja sakta hai.
  • (3) ismein anek sachar sandhaaritron ke badle ek asthir radio aavrutti pravardhak mein kai pravardhak padon ko sammilit kar abheesht uchch aavardhan praapt kiya ja sakta hai, isliye ye sangraahi apekshaakrut saste bhi hote hain. saath hi inke bhaar mein bhi anaavashyak vruddhi naheen hone paati.

inhein bhi dekhein

baahari kadiyaaain