Radiyo ikhoza kuoneka ngati matsenga, koma ndizosangalatsa kwambiri kumvetsa
Nthawi zambiri, ena a ife timakhala tikuzindikira kuti FM / FM imamva ngati matsenga. Mukasintha pawailesi, mumatha kumvetsera nyimbo, mawu, kapena zosangalatsa zina zilizonse zomwe zimatulutsidwa kuchokera ku gwero lomwe lilipo mazana-kapena zikwi-makilomita kutali! N'zomvetsa chisoni kuti sizimatsenga. Ndipotu, phwando la wailesi ndi losavuta kumvetsa kamodzi mukasokoneza momwe mafunde a ma radiyo amapangidwira ndikufalitsidwa.
Kodi Mafilimu Adailesi Ndi Chiyani?
Mwinamwake mumadziŵika ndi AM, omwe amaimira Amplitude Modulation , ndi FM, omwe amaimira Frequency Modulation . Mapulogalamu onse a AM ndi FM akufalitsidwa pamlengalenga pogwiritsa ntchito mafunde, omwe ndi mbali ya mafunde amphamvu omwe amagwiritsa ntchito: ma gamma, ma-ray, mazira a ultraviolet, kuwala kooneka, ma infrared, ndi microwave. Mafunde a magetsi akuzungulira ife paliponse m'madera osiyanasiyana. Mafunde a ma wailesi amachititsa zinthu zofanana ndi mafunde amphamvu (mwachitsanzo, kusinkhasinkha, kufotokoza, kutsekemera, kutsekemera), koma amakhalapo nthawi zambiri zomwe maso athu sakuzimva.
Mafunde a magetsi amapangidwa ndi kusinthasintha zamakono (AC), omwe ndi mphamvu yamagetsi yogwiritsira ntchito zipangizo zamtundu uliwonse ndi / kapena teknoloji m'nyumba zathu ndi miyoyo yathu - kuchokera ku makina otsuka ku televiziyo ku mafoni athu. Ku United States, makina osinthika amagwiritsidwa ntchito pa 120 volts pa 60 Hz. Izi zikutanthawuza kuti zosinthika zamakono (kusintha maulendo) mu waya 60 kamphindi. Maiko ena amagwiritsa ntchito 50 Hz monga momwe zilili. Ngakhale kuti ma 50 ndi 60 Hz amaonedwa kuti ndi ofanana kwambiri, mafunde ena osakanikirana akupitirizabe kupanga magetsi oyendera magetsi (EMR). Izi zikutanthauza kuti mphamvu zina zamagetsi zimachokera pa waya ndipo zimafalitsidwa mlengalenga. Kuthamanga kwa magetsi, mphamvu zambiri zomwe zimatha kuthawa waya kupita kumalo osatsegula. Motero, magetsi a magetsi amatha kufotokozedwa momveka ngati 'magetsi mumlengalenga'.
Mutu wa Kusinthika
Magetsi mumlengalenga sali kanthu koma phokoso losavuta. Kuti zikhale zizindikiro zabwino zomwe zimafalitsa uthenga (nyimbo kapena liwu) izo ziyenera kuti ziyambe kusinthidwa, ndipo kusinthika ndi maziko a chizindikiro cha AM ndi FM. Ndi momwe AM ndi FM zinayambira, popeza AM imayimira ma amplitude modulation ndi ma FM akuyimira maulendo ambiri.
Liwu lina la kusinthika ndi kusintha. Miyendo yamagetsi ya magetsi imayenera kusinthidwa kapena kusinthidwa kuti ikhale yogwiritsidwa ntchito ngati mauthenga a wailesi. Popanda kufikitsa mawu, palibe chidziwitso chomwe chidzachitike ndi chizindikiro cha wailesi. Kusinthasintha mawu ndi losavuta kumvetsetsa, makamaka popeza kulizungulira. Malingaliro athu a masomphenya ndi chitsanzo chabwino kufotokoza momwe kusinthika kumagwirira ntchito. Mukhoza kukhala ndi pepala lopanda kanthu m'manja mwanu, komabe n'kopanda phindu mpaka itasinthidwa kapena kusinthidwa m'njira ina. Winawake ayenera kulemba kapena kujambula pa pepala kuti alankhule zambiri zothandiza.
Chinthu china chabwino kwambiri ndikumvetsetsa kwathu. Mpweya wopanda pake uyenera kusinthidwa kapena kusinthidwa ndi nyimbo kapena mawu kapena mawu kuti zikhale zothandiza. Mofanana ndi pepala, mamolekyu omwe amapanga mpweya ndiwo zonyamulira zowunikira. Koma popanda chidziwitso chenicheni - zilembo pamapepala kapena kumveka mlengalenga - mulibe kanthu. Choncho pankhani ya mauthenga a pa wailesi, magetsi opangira magetsi (magetsi mumlengalenga) ayenera kusinthidwa ndi zomwe akufuna kuti atumize.
Makanema a AM AM
Ma wailesi amtundu wa AM amatha kugwiritsa ntchito maulamuliro amphamvu ndipo ndi njira yosavuta yofalitsira wailesi. Kuti mumvetse kutsetsereka kwa matalikidwe, ganizirani chizindikiro chodziwika bwino (kapena vesi) pa 1000 kHz pa AM band. Matalikidwe (kapena kutalika) kwa chizindikiro chosasinthika sasinthidwa kapena osasinthidwa, motero alibe mfundo zothandiza. Chizindikiro chokhazikikacho chimangomveka phokoso pokhapokha kuti liwonetsedwe ndi chidziwitso, monga mawu kapena nyimbo. Kuphatikizidwa kwaziwiri kumasintha ku mphamvu yamakono ya chizindikiro chokhazikika, chomwe chimawonjezeka ndi kuchepa molunjika molingana ndi chidziwitso. Matalikidwe okha ndi omwe amasintha, monga momwe nthawi zonse zimakhazikika nthawi zonse.
Mawailesi AM ku America amagwira ntchito maulendo angapo kuyambira 520 kHz mpaka 1710 kHz. Maiko ena ndi madera ali ndi malire osiyanasiyana. Nthawi yodziwikiratu imadziwika ngati nthawi yothandizira , yomwe ndi galimoto yomwe chizindikiro chenicheni chimatengedwa kuchokera ku antenna kulandiridwa.
Radiyo AM ili ndi ubwino wofalitsa kusiyana kwakukulu, kukhala ndi malo ochulukirapo pafupipafupi, ndi kusankhidwa mosavuta ndi olandira. Komabe, zizindikiro za AM zimangokhala phokoso komanso kusokonezeka , monga nthawi yamkuntho. Magetsi opangidwa ndi mphezi amapanga ziphuphu za phokoso zomwe zimatengedwa ndi AM tuners. Radiyo ya AM imakhala ndi mafilimu ochepa kwambiri, kuyambira 200 Hz mpaka 5 kHz, zomwe zimapangitsa kuti zitheke kuyankhulana ndi wailesi komanso zochepera nyimbo. Ndipo pankhani ya nyimbo, zizindikiro za AM zili ndi khalidwe lakumveka kuposa FM.
Mauthenga a Ma wailesi a FM
Ma wailesi a FM amagwiritsira ntchito maulendo ambiri. Kuti mumvetse kayendedwe kake kawirikawiri, ganizirani chizindikiro chokhala ndi nthawi yambiri komanso kukula kwake. Nthawi zambiri chizindikirocho chosasinthika kapena chosasinthika, kotero palibe mfundo zothandiza zomwe zilipo. Koma pokhapokha ngati atapatsidwa chidziwitso ku chizindikiro ichi, kuphatikiza kumabweretsa kusintha kwafupipafupi , zomwe ziri zofanana molingana ndi chidziwitso. Pamene maulendowa amadziwika pakati pazitali ndi zapamwamba, nyimbo kapena mawu akufalitsidwa ndifupipafupi. Koma kokha kawirikawiri amasintha monga zotsatira; matalikidwe amakhalabe nthawi zonse nthawi yonse.
Ma wailesi a FM amagwira ntchito pa 87.5 MHz mpaka 108.0 MHz, omwe ndi maulendo apamwamba kuposa ailesi ya AM. Mtunda wamtundu wa FM ukuchepa kwambiri kuposa AM - nthawi zambiri zosakwana makilomita 100. Komabe, ma wailesi a FM ali oyenerera nyimbo; kutalika kwapakati pa 30 Hz kufika 15 kHz kumabala khalidwe lakumveka lomwe timakonda kumvetsera ndi kusangalala. Koma pofuna kukhala ndi malo akuluakulu, kufalitsa kwa FM kumafuna zowonjezera maofesi kuti azitsatira zizindikiro.
Mauthenga a FM amachitanso kawirikawiri pa stereo - malo ochepa AM amatha kufalitsa zizindikiro za stereo. Ndipo ngakhale kuti zizindikiro za FM sizingatheke phokoso ndi kusokonezeka, zikhoza kuchepetsedwa ndi zolepheretsa zakuthupi (mwachitsanzo nyumba, mapiri, etc.), zomwe zimakhudza phwando lonse. Ichi ndichifukwa chake mungatenge malo ena ochezera maulendo mosavuta m'malo ena, kaya ali mkati mwanu kapena pafupi ndi mzinda.