Въведение
Относно AntennaAmplifier
AntennaamplifierisgenerallycalledMastheaderAmplifierinEnglish,anditisalsocalledPre-amplifierorAntennaAmplifier,Amplificador,etc.insomeEuropeanandAmericancountries.UHF,broadband,lownoiseamplifierbetweenantennaandfeeder.TocompensateforthelossofthetransmissiondistancebetweentheantennaandtheTV,andtoensurethatthedistributorobtainsthenecessaryinputpowerinthesharedantennasystem.
Whenwereceivelong-distanceTVprogramsorterrestrialhigh-definitionTVprograms,theTVsignalisgenerallyweak.Atthistime,weneedtouseamulti-unitTVantennawithstrongdirectivityandhighgain,andtheantennaSetitupashighaspossibleandinanopenplace.Ifyoufeelthatthereceivingsituationisnotidealenough,youneedtoinstallanantennaamplifierbetweentheantennaandtheTVtoincreasethereceivingsensitivity,sothattheTV’simageisstableandthesoundisgood.
Afterusingtheantennaamplifier,itislikeaddinga"telescope"totheTV.ItcanamplifytheweakTVsignalreceivedbytheantenna,butofcourse,intheprocessofreceiving,morethanjustamplifyingIt'saTVsignal,anditalsoincludesallkindsofnoiseandinterference.UsuallyundertheantennaamplifiercanamplifytheTVsignaltotentimesormore.Theantennaamplifierisactuallyasuperhigh-bandamplifier.Thereceivingchannel,frequencyrangeandoverallgainofvarioustypesofantennaamplifiersaredifferent.
Payattentiontotheproblem
(1)PayattentiontotheinstallationpositionTheantennaamplifierusuallyconsistsoftwoparts:theamplifyingpartandthepowersupply.Whentheantennafeederlineisshort(generallyreferstotheuseofindoorantennas),theantennaamplifiercanbeplacednexttotheTV;whentheantennaissetuphigherandthefeederlineislonger,thetwopartsshouldbeplacedseparately,andtheamplifyingpartshouldbesealedbyawaterproofboxLater,itisbesttoinstallitattheendofthesupportrod1~1.5mawayfromtheantennaelement,andthepowersupplypartcanbeplacedneartheTV,whichcanimprovethesignal-to-noiseratiooftheTVsignal.
(2)Channelsmustmatch.Antennaamplifiersaregenerallydividedintotwocategories:VHFandUHF.TheVHFtypecanamplifytheTVsignalofchannels1to12,andtheUHFtypecanamplifytheTVsignalofchannels13to68.Wheninuse,theantennaamplifiershouldmatchtheTVchanneltobereceived.
(3)PayattentiontoimpedancematchingTheoutputimpedanceoftheantennaamplifierandtheoutputendoftheantennaandtheinputimpedanceoftheTVshouldallmatch.Thefeedershouldnotbetoolong,thatistosay,theantennashouldnotbeerectedtoohighortoofar.Otherwise,althoughtheantennaamplifierisaddedtotheTV,theincreasedsignalwillbeseverelyattenuatedduringthetransmissiontotheTV,resultinginlittleimprovementinthereceivingeffect.Inaddition,theinputandoutputfeedlinesoftheantennaamplifiercannotoverlaporbetooclosetoavoidfeedbackorinterference.
(4)Thegainmustbeselected.Thegainofvarioustypesofantennaamplifiersisdifferent,generallytherearehighandlowpoints.High-gainantennaamplifiersusuallyhaveagainof30to60dB,andinconjunctionwithamulti-channelYagiantenna,theycanreceiveTVprogramshundredsofkilometersaway.Thelow-gainantennaamplifierhasagainof20-40dBandcanreceiveprogramsdozensofkilometersaway.Itisnecessarytomakeaproperchoicewhenchoosing,butitisnotthatthehigherthegain,thebetter.
(5)Checktheinstallationeffect.Iftheimagereceivedbytheindoorcableispoor,andgoodresultscanbeobtainedwheninstallinganoutdoorantenna,youcanstillusetheindoorantennaafterusingtheamplifier.Ifafterinstallingtheantennaamplifier,theTVviewingeffectdoesnotchangesignificantly,ortheviewingeffectisworsethanbefore,itiscausedbyaninstallationerror,andyoushouldcheckitcarefullybeforecorrectingitaccordingtothecorrectinstallationmethod.
(6)Goodantennasandlightningprotectionequipment,suchasTVuserswhouseoutdoorantennas,needtoinstallanantennaamplifier,andagoodmulti-elementantennamustbeusedtocooperatewithit,andlightningprotectionequipmentmustbeinstalledtopreventLightningstrikes.
Критерии за преценка на качествата
Първо, сигналът и шумът трябва да са малки
Второ, чувствителността трябва да е висока
Третото трябва да е по-добро по отношение на водоустойчивостта
Четири тома е по-малък
Fivemetalshellisbetter
Sixpowersaving
Седем кабела е удобно
Добре позната маркаh2>
Отвъд океана: Antiference,Global,Johansson,Fracarro,Fringe,Ikusi,IkusiLabgear,Maxview,Paragon,Philex,Proception,Televes,Triax,Vision,Wolsey
ButmostoftheaboveproductsaremainlyProducedinSoutheastAsia,especiallyinChina.
Domestic:Boligo,Seebest,Wanshida,Wanshibao,Jiaxun
ThesebrandsarealsotheOEMsofmanyforeignbrands,andsomeofthebrands'productqualitycanbestraightforward.Referstofirst-lineforeignbrands.
Architecturediagram
Thisillustrationtellstheuserhowtoconnectfromtheantennatotheamplifiertothepowersupplytotheuser.Butthislegendisnotclearenough.Becausetheantennaamplifierisalsocalledpreamplifier,itisbecausetheantennaamplifierisinstalledlessthan30cmbelowtheantenna,andthegeneralpowersupplywillbeinstallednexttotheTV,sothatthesignallinecanbedirectlyinsertedintotheTV.IfmultipleTVsreceiveaprogramononeantenna,thepowersupplyisgenerallyplacednearthebranchdistributor.Asforwhethertowatchhigh-definitionTVprogramsoranalogprograms,itdependsontheconfigurationofyourTV.Atpresent,mid-to-high-endflat-panelTVshavebuilt-interrestrialhigh-definitionset-topboxmodules,someofwhicharecalledall-in-ones,andthetechnologyisverymature.Comparedwithbroadcastandtelevisionsignals,terrestrialhigh-definitionprogramsarefree,andtheinitialinstallationcostisrelativelylow.Aslongasyouchoosehigh-qualityantennasandantennaamplifiers,youcanreceiveultra-high-definitionprogramsinmpg-2orevenmpg-4format.
Applicationexample
Inthisexample,themostbasicequipmentsuchasthehomeantennaamplifier7322andbranchdistributorofJohanssoninBelgiumareused.TheEuropeantestreportindicatedthatHDTVcanbereceivedinopenconditions,evenifitisonthesideofthehighway,closetothemobilebasestationorSanyin,etc.,itcanstillachieveaclearervideosignal,withidealgainandanti-interference.,Especiallyintermsofanti-mobilesignalinterference,itisworthyofrecognition.DirectTV,theworld'slargestproviderofsatelliteTVlivebroadcastsandterrestrialhigh-definitionprograms,iscooperatingwiththisbrand.
Разбира се, има някои местни марки, които могат да постигнат това качество.