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FM
FM គឺជាពាក្យកាត់នៃពាក្យ Frequency Modulation។
[[File:Amfm2.gif|thumb|right|A sound wave, an '''AM''' wave, and an '''FM''' wave compared]]

In [[telecommunication]]s and [[signal processing]], '''Frequency modulation''' transmits [[information]] over a [[carrier wave]] byvarying the [[frequenxy]].  This technique is different from [[amplitude modulation]] which varies the [[amplitude]], but keeps the frequency constant. In the context of [[broadcasting]] [[radio]] [[signal]]s, Frequency modulation is often shortened to '''FM'''. When transmitting [[analogue]] [[sound]],  the sound quality of FM signals is better than that of [[amplitude modulation]] (AM) signals. However, FM signals do not travel as far as AM.

Many radio stations send out both kinds of signals, reserving AM for talk shows, and FM for music. In addition, FM is usually sent as two signals (with one signal's frequency a little lower than the other), which can come to two different speakers in a home. This creates FM [[stereo]] sound.

== Other websites ==
* [http://www.rfcafe.com/references/electrical/frequency_modulation.htm Frequency Modulation] 
* [http://www.fas.org/man/dod-101/navy/docs/es310/FM.htm Frequency Modulation]
{{Tech-stub}}

[[Category:Radio]]⏎
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[[am:ድግግሞሽ መከርከም]]
[[ar:تضمين التردد]]
[[bg:Честотна модулация]]
[[ca:Freqüència modulada]]
[[cs:Frekvenční modulace]]
[[da:Frekvensmodulation]]
[[de:Frequenzmodulation]]
[[el:Διαμόρφωση συχνότητας]]
[[en:Frequency modulation]]
[[es:Frecuencia modulada]]
[[eu:Frekuentzia Modulatua]]
[[fa:مدولاسیون فرکانس]]
[[fi:Taajuusmodulaatio]]
[[fr:Modulation de fréquence]]
[[he:אפנון תדר]]
[[hi:आवृत्ति मॉड्यूलेशन]]
[[hr:Frekvencijska modulacija]]
[[id:Modulasi frekuensi]]
[[it:Modulazione di frequenza]]
[[ja:周波数変調]]
[[ka:სიხშირული მოდულაცია]]
[[kn:ಆವರ್ತ ಮಾರ್ಪಡಿಸುವಿಕೆ]]
[[ko:주파수 변조]]
[[lv:Frekvences modulācija]]
[[ml:ഫ്രീക്വൻസി മോഡുലേഷൻ]]
[[ms:Modulasi frekuensi]]
[[nl:Frequentiemodulatie]]
[[no:Frekvensmodulasjon]]
[[pl:Modulacja częstotliwości]]
[[pt:Modulação em frequência]]
[[ru:Частотная модуляция]]
[[simple:Frequency modulation]]
[[sk:Frekvenčná modulácia]]
[[sl:Frekvenčna modulacija]]
[[sr:Фреквенцијска модулација]]
[[su:Modulasi frékuénsi]]
[[sv:Frekvensmodulering]]
[[ta:அதிர்வெண் பண்பேற்றம்]]
[[tr:Frekans modülasyonu]]
[[uk:Частотна модуляція]]
[[ur:تعددی تضمیص]]
[[vi:Điều chế tần số]]
[[zh:频率调制]]