Ph\u00e1t thanh c\u1ee7a \u0111i\u1ec7n \u0111\u00e0i s\u00f3ng ng\u1eafn ph\u00e1t ra, ph\u1ea7n nhi\u1ec1u \u0111\u1ebfn t\u1eeb n\u01b0\u1edbc ngo\u00e0i x\u1ee9 l\u1ea1. Song, ra\u0111i\u00f4 n\u00f3i chung th\u00f4ng th\u01b0\u1eddng ch\u1ec9 c\u00f3 m\u1ed9t hai b\u0103ng s\u00f3ng ng\u1eafn, \u0111\u00e0i ph\u00e1t thanh s\u00f3ng ng\u1eafn c\u00f3 th\u1ec3 thu \u0111\u01b0\u1ee3c ch\u1ec9 \u0111\u1ebfm \u0111\u1ea7u ng\u00f3n tay, v\u1eady m\u00e0 l\u1ea1i hay “chen l\u1ea5n” nhau, xu\u1ea5t hi\u1ec7n b\u1eaft nh\u1ea7m \u0111\u00e0i, ti\u1ebfng n\u00f3i l\u00fac to l\u00fac nh\u1ecf, r\u1ea5t kh\u00f4ng \u1ed5n \u0111\u1ecbnh. N\u00f3i theo thu\u1eadt ng\u1eef v\u00f4 tuy\u1ebfn \u0111i\u1ec7n, lo\u1ea1i ra\u0111i\u00f4 \u0111\u00f3 c\u00f3 \u0111\u1ed9 nh\u1ea1y th\u1ea5p, t\u00ednh l\u1ecdc l\u1ef1a k\u00e9m, b\u0103ng thu c\u0169ng kh\u00e1 h\u1eb9p.<\/p>\n\n\n\n
Tr\u00ean qu\u1ed1c t\u1ebf quy \u0111\u1ecbnh, ph\u1ea1m vi t\u1ea7n s\u1ed1 s\u00f3ng ng\u1eafn d\u00e0nh cho ph\u00e1t thanh trong d\u1ea3i t\u1ea7n s\u1ed1 v\u00f4 tuy\u1ebfn \u0111i\u1ec7n l\u00e0 2,3 ~ 26,1 megahec (MHz). C\u00e1c \u0111\u00e0i ph\u00e1t thanh c\u1ee7a c\u00e1c n\u01b0\u1edbc tr\u00ean th\u1ebf gi\u1edbi \u0111\u1ec1u c\u00f3 th\u1ec3 ph\u00e1t ra ph\u00e1t thanh s\u00f3ng ng\u1eafn \u1edf trong ph\u1ea1m vi c\u1ee7a \u0111o\u1ea1n t\u1ea7n s\u1ed1 \u0111\u00f3. N\u1ebfu ra\u0111i\u00f4 c\u00f3 \u0111\u1ee7 \u0111\u1ed9 nh\u1ea1y v\u00e0 t\u00ednh l\u1ecdc l\u1ef1a t\u1ed1t th\u00ec c\u00f3 th\u1ec3 thu \u0111\u01b0\u1ee3c c\u00e1c ti\u1ebft m\u1ee5c ph\u00e1t thanh c\u1ee7a c\u00e1c \u0111\u00e0i s\u00f3ng ng\u1eafn c\u1ee7a c\u00e1c n\u01b0\u1edbc tr\u00ean th\u1ebf gi\u1edbi.<\/p>\n\n\n\n
Nh\u01b0ng, b\u0103ng s\u00f3ng ng\u1eafn th\u1ee9 nh\u1ea5t (SW 1) c\u1ee7a ra\u0111i\u00f4 n\u00f3i chung l\u00e0 4 ~ 9 MHz, b\u0103ng s\u00f3ng ng\u1eafn th\u1ee9 hai (SW 2) l\u00e0 kho\u1ea3ng 9 – 18 MHz, b\u0103ng thu t\u1ed5ng th\u1ec3 \u1edf trong 4 ~ 18 MHz, ch\u1ec9 chi\u1ebfm c\u00f3 m\u1ed9t ph\u1ea7n c\u1ee7a c\u1ea3 \u0111o\u1ea1n ph\u00e1t thanh s\u00f3ng ng\u1eafn, v\u1eady l\u00e0 c\u00f3 nhi\u1ec1u \u0111\u00e0i s\u00f3ng ng\u1eafn b\u1ecb g\u1ea1t ra r\u00eca.<\/p>\n\n\n\n
Trong b\u0103ng thu s\u00f3ng ng\u1eafn c\u1ee7a ra\u0111i\u00f4, \u0111\u1ed9 nh\u1ea1y thu s\u00f3ng kh\u00f4ng \u0111\u1ed3ng \u0111\u1ec1u. \u1ede ph\u1ea7n qu\u00e1 cao v\u00e0 qu\u00e1 th\u1ea5p c\u1ee7a b\u0103ng thu, \u0111\u1ed9 nh\u1ea1y thu s\u00f3ng \u0111\u1ec1u t\u01b0\u01a1ng \u0111\u1ed1i th\u1ea5p. C\u00f2n \u1edf ph\u1ea7n gi\u1eefa c\u1ee7a b\u0103ng thu s\u00f3ng th\u00ec \u0111\u1ed9 nh\u1ea1y \u0111\u00f3 t\u01b0\u01a1ng \u0111\u1ed1i cao.<\/p>\n\n\n\n
\u0110\u1ed1i v\u1edbi ra\u0111i\u00f4 n\u00f3i chung, ph\u1ea1m vi t\u1ea7n s\u1ed1 c\u1ee7a b\u0103ng s\u00f3ng ng\u1eafn t\u01b0\u01a1ng \u0111\u1ed1i r\u1ed9ng. V\u00ed d\u1ee5 b\u0103ng SW 1 r\u1ed9ng t\u1edbi 5 MHz. Trong ph\u1ea1m vi b\u0103ng thu r\u1ed9ng nh\u01b0 v\u1eady, \u0111\u1ed9 nh\u1ea1y thu s\u00f3ng cao cao th\u1ea5p th\u1ea5p, r\u1ea5t kh\u00f4ng \u0111\u1ed3ng \u0111\u1ec1u. Nh\u01b0 v\u1eady th\u00ec kh\u00f4ng th\u1ec3 n\u00e0o th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c s\u1ef1 “\u0111\u1ed1i x\u1eed nh\u01b0 nhau” v\u1edbi m\u1ecdi \u0111\u00e0i ph\u00e1t thanh s\u00f3ng ng\u1eafn. C\u00f3 \u0111\u00e0i c\u00f3 t\u1ea7n s\u1ed1 v\u1eeba kh\u00e9o \u1edf trong ph\u1ea1m vi \u0111\u1ed9 nh\u1ea1y thu s\u00f3ng t\u01b0\u01a1ng \u0111\u1ed1i cao, \u0111\u00e0i \u0111\u00f3 s\u1ebd d\u1ec5 \u0111\u01b0\u1ee3c thu s\u00f3ng. C\u00f2n nh\u1eefng \u0111\u00e0i m\u00e0 t\u1ea7n s\u1ed1 l\u1ea1i \u1edf v\u00e0o ch\u1ed7 \u0111\u1ed9 nh\u1ea1y thu s\u00f3ng c\u1ee7a ra\u0111i\u00f4 t\u01b0\u01a1ng \u0111\u1ed1i th\u1ea5p, mu\u1ed1n thu \u0111\u01b0\u1ee3c ph\u1ea3i kh\u00e1 v\u1ea5t v\u1ea3.<\/p>\n\n\n\n
V\u1ea3 l\u1ea1i, s\u00f3ng v\u00f4 tuy\u1ebfn \u0111i\u1ec7n m\u00e0 m\u1ed7i \u0111\u00e0i ph\u00e1t thanh s\u00f3ng ng\u1eafn ph\u00e1t ra \u0111\u1ec1u c\u00f3 ph\u1ea1m vi t\u1ea7n s\u1ed1 nh\u1ea5t \u0111\u1ecbnh, n\u00f3 ch\u1ec9 chi\u1ebfm m\u1ed9t \u0111\u1ed9 r\u1ed9ng nh\u1ea5t \u0111\u1ecbnh tr\u00ean b\u0103ng thu s\u00f3ng ng\u1eafn c\u1ee7a ra\u0111i\u00f4. Khi ra\u0111i\u00f4 c\u00f3 t\u00ednh l\u1ecdc l\u1ef1a t\u1ed1t thu nghe, d\u1ec5 d\u00e0ng ch\u1ec9nh b\u1eaft \u0111\u01b0\u1ee3c s\u00f3ng c\u1ee7a \u0111\u00e0i ph\u00e1t, c\u00f2n ra\u0111i\u00f4 c\u00f3 t\u00ednh l\u1ecdc l\u1ef1a k\u00e9m th\u00ec th\u01b0\u1eddng l\u00e0 b\u00ean c\u1ea1nh m\u1ed9t \u0111\u00e0i ph\u00e1t c\u00f2n c\u00f3 m\u1ed9t \u0111\u00e0i ph\u00e1t kh\u00e1c k\u1ec1 s\u00e1t v\u00e0o, v\u00e0i \u0111\u00e0i ph\u00e1t chen l\u1ea5n v\u00e0o m\u1ed9t ch\u1ed7, v\u1ea5t v\u1ea3 l\u1eafm m\u1edbi ch\u1ec9nh b\u1eaft \u0111\u01b0\u1ee3c s\u00f3ng c\u1ee7a m\u1ed9t \u0111\u00e0i ph\u00e1t, h\u01a1i nh\u00edch n\u00fam v\u1eb7n t\u00ecm s\u00f3ng m\u1ed9t ch\u00fat l\u00e0 \u0111\u00e0i ph\u00e1t \u0111ang nghe li\u1ec1n “bi\u1ebfn” m\u1ea5t.<\/p>\n\n\n\n
N\u1ebfu c\u00f3 th\u1ec3 m\u1edf r\u1ed9ng b\u0103ng s\u00f3ng ng\u1eafn c\u1ee7a ra\u0111i\u00f4 bao qu\u00e1t h\u1ebft c\u1ea3 ph\u1ea1m vi t\u1ea7n s\u1ed1 c\u1ee7a \u0111o\u1ea1n ph\u00e1t thanh s\u00f3ng ng\u1eafn, th\u1ebf th\u00ec c\u00f3 kh\u1ea3 n\u0103ng thu \u0111\u01b0\u1ee3c t\u1ea5t c\u1ea3 c\u00e1c \u0111\u00e0i ph\u00e1t thanh s\u00f3ng ng\u1eafn trong \u0111o\u1ea1n \u0111\u00f3. Chia nh\u1ecf \u0111o\u1ea1n thu thanh s\u00f3ng ng\u1eafn ra th\u00e0nh v\u00e0i ph\u00e2n \u0111o\u1ea1n, \u00e1p d\u1ee5ng bi\u1ec7n ph\u00e1p “chia \u0111\u1ec3 tr\u1ecb” \u0111\u1ed1i v\u1edbi nh\u1eefng ph\u00e2n \u0111o\u1ea1n n\u00e0y, l\u1ea7n l\u01b0\u1ee3t ti\u1ebfn h\u00e0nh x\u1eed l\u00ed k\u0129 thu\u1eadt, l\u00e0m cho trong m\u1ed7i ph\u00e2n \u0111o\u1ea1n \u0111\u1ec1u c\u00f3 \u0111\u1ed9 nh\u1ea1y \u0111\u1ed3ng \u0111\u1ec1u v\u00e0 \u0111\u1ea7y \u0111\u1ee7. Nh\u01b0 v\u1eady, khi thu \u0111\u00e0i ph\u00e1t thanh s\u00f3ng ng\u1eafn li\u1ec1n c\u00f3 th\u1ec3 th\u1ef1c hi\u1ec7n \u0111\u01b0\u1ee3c s\u1ef1 “\u0111\u1ed1i x\u1eed nh\u01b0 nhau” v\u1edbi m\u1ecdi \u0111\u00e0i ph\u00e1t thanh s\u00f3ng ng\u1eafn. H\u01a1n n\u1eefa, trong m\u1ecdi ph\u00e2n \u0111o\u1ea1n, ra\u0111i\u00f4 c\u00f3 th\u1ec3 c\u00f3 t\u00ednh l\u1ecdc l\u1ef1a t\u1ed1t. Hi\u1ec7n nay, c\u00f3 lo\u1ea1i ra\u0111i\u00f4 \u0111\u00e3 c\u00f3 t\u00e1m, ch\u00edn b\u0103ng (ph\u00e2n \u0111o\u1ea1n) s\u00f3ng ng\u1eafn, c\u00f3 lo\u1ea1i th\u1eadm ch\u00ed nhi\u1ec1u t\u1edbi 20 ~ 30 b\u0103ng s\u00f3ng ng\u1eafn.<\/p>\n\n\n\n
T\u1eeb kho\u00e1: Ra\u0111i\u00f4; B\u0103ng s\u00f3ng ng\u1eafn; Ch\u1ec9nh b\u1eaft s\u00f3ng; \u0110\u1ed9 nh\u1ea1y.<\/p>\n\n\n\n
<\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":"
Ph\u00e1t thanh c\u1ee7a \u0111i\u1ec7n \u0111\u00e0i s\u00f3ng ng\u1eafn ph\u00e1t ra, ph\u1ea7n nhi\u1ec1u \u0111\u1ebfn t\u1eeb n\u01b0\u1edbc ngo\u00e0i x\u1ee9 l\u1ea1. Song, ra\u0111i\u00f4 n\u00f3i chung th\u00f4ng th\u01b0\u1eddng ch\u1ec9 c\u00f3 m\u1ed9t hai b\u0103ng s\u00f3ng ng\u1eafn, \u0111\u00e0i ph\u00e1t thanh s\u00f3ng ng\u1eafn c\u00f3 th\u1ec3 thu \u0111\u01b0\u1ee3c ch\u1ec9 \u0111\u1ebfm \u0111\u1ea7u ng\u00f3n tay, v\u1eady m\u00e0 l\u1ea1i hay “chen l\u1ea5n” nhau, xu\u1ea5t hi\u1ec7n b\u1eaft nh\u1ea7m […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_disable_autopaging":false},"categories":[15,7],"tags":[],"class_list":["post-5926","post","type-post","status-publish","format-standard","hentry","category-hoi-dap-khoa-hoc","category-vat-ly"],"_links":{"self":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/5926","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/comments?post=5926"}],"version-history":[{"count":0,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/5926\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=5926"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=5926"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=5926"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}