Eriya mai aiki 1 zuwa 20dB, zangon 1-30 MHz

Eriya mai aiki 1 zuwa 20dB, zangon 1-30 MHz.byRodney A. KreuterandTony van Roon

“Lokacin da makusanci ko makwabta suka hana ka yin amfani da eriyar waya mai dogon zango, zaku ga cewa wannan eriyar mai girman aljihunan zata bayar iri ɗaya, ko kuma mafi kyau, liyafar. Wannan "Antenna mai aiki" mai arha ne don gina "kuma yana da kewayon 1 zuwa 30Mhz tsakanin ribar 14 zuwa 20dB."
Fko maraba na gajeren zango-gajere na al'ada, babban jigon shine "mafi tsawo cikin antennal mai ƙarfi siginar da aka karɓa." Abin baƙin ciki, tsakanin maƙwabta mara kyau, ƙaƙƙarfan ƙa'idojin gidaje, da shirye-shiryen kadara waɗanda ba su fi girma fiye da tambur, gajere - eriya sau da yawa yakan juya ya zama feetan ƙafa na waya waɗanda aka jefa ta taga-maimakon ƙafafun 130 na dogon wuriyar waya da gaske muna son ɗaura tsakanin hasumiya mai kafa 50 XNUMX.

An yi sa'a, akwai wani zaɓi da ya dace da eriyar dogayen waya, kuma wannan eriya mai aiki; wanda ya ƙunshi madaidaicin eriya mai ɗan gajeren lokaci da kuma babban amplifier. Rukunin kaina na aiki cikin nasara tsawon kusan shekaru goma. Yana aiki mai gamsarwa.

Manufar eriya mai aiki abu ne mai sauki. Tun da eriya ta kasance ƙarami ne, ba ta hana ƙarfi kamar babban eriya, saboda haka muna amfani da amplifier RF-ginan ne don karɓar siginar alama ta "asara." Hakanan, amplifier yana samar da daidaituwa mai dacewa, saboda yawancin masu karɓa an tsara su don aiki tare da eriyar 50-ohm.

Za'a iya gina eriya mai aiki don kowane kewayon mitar, amma ana amfani dasu da yawa daga VLF (10KHz ko makamancin haka) zuwa kusan 30MHz. Dalilin hakan shine saboda antennas masu cikakken girma na waƙoƙin galibi suna da tsawo sosai ga sararin samaniya. A mafi girman saƙo, yana da sauƙin ƙirƙirar eriya mai sauƙi.

Eriya mai aiki da aka nuna a ƙasa (Hoto 1), tana samar da riba 14-20dB a sanannen gajeren zango da rediyo mai son rediyo na 1-30MHz. Kamar yadda zaku yi tsammani, ƙananan mitar mafi girma da riba. Samun riba na 20dB kwatankwacinsa ne daga 1-18 MHz, yana raguwa zuwa 14dB a 30MHz.

Tsarin da'ira:
Saboda eriya waɗanda suka fi gaɓoɓin zango 1/4 suna gabatar da ƙarami kaɗan kuma mai tasirin gaske wanda ya dogara da karɓar karɓar, babu wani yunƙuri da aka yi don dacewa da tasirin eriya-hakan zai iya zama da wuya matuƙar wahala kuma takaici don daidaitawa kan tsinkaye a cikin shekaru goma na yawan kewayawa. Madadin haka, tsarin shigarwar (Q1) mai bibiyar JFET ne, wanda shigarwar shi ke kawo babban tasiri a cikin yanayin halayen eriya a kowane mita. Kodayake ana iya amfani da nau'ikan JFET daban-daban-kamar MPF102, NTE451, ko 2N4416 –ka tuna cewa ana mayar da martani na gaba-ɗaya a sifofin JFET amplifier.

Ana amfani da Transistor Q2 a matsayin mai bin emitter don samar da nauyin mai ƙarfi na Q1, amma mafi mahimmanci, yana samar da ƙarancin tuƙin hanyar don amplifier na gama gari-Q3, wanda ke samar da dukan na amplifier ta lantarki ƙarfin lantarki. Mafi mahimmancin sigar Q3 shine fT, yanke-mai-girma, wanda yakamata ya kasance cikin kewayon 200-400 MHz. A 2N3904, ko 2N2222 yana aiki da kyau don Q3.

Mafi mahimmancin ma'aunin da'irar Q3 shine saukewar wutar lantarki a duk faɗin R8: Mafi girman faɗuwar, mafi girma riba. Koyaya, lambar wucewa ta ragu yayin da ribar Q3 ke karuwa.

Transistor Q4 yana canza matsakaicin kayan fitarwa na Q3 zuwa matsakaici mai sauƙi, ta haka yana samar da wadataccen drive don karɓar shigarwar eriyar 50-ohm mai karɓa.

Tsarin Zane-zane Mai Jiran Antenna

Jerin sassan da sauran abubuwanda aka gyara:

Semiconductors:
      Q1 = MPF102, JFET. (2N4416, NTE451, ECG451, da sauransu) Q2, Q3, Q4 = 2N3904, NPN transistor

Masu sake tsayawa:
All Resistors sune 5%, 1/4-watt
    R1 = 1 MegOhm R5 = 10K R2, R10 = 22 ohm R6, R9 = 1K R3, R11 = 2K2 R7 = 3K3 R4 = 22K R8 = 470 ohm

Capacitors (wanda aka kiyasta aƙalla 16V):
   C1, C3 = 470pF C2, C5, C6 = 0.01uF (10nF) C4 = 0.001uF (1nF) C7, C9 = 0.1uF (100nF) C8 = 22uF / 16V, electrolytic

Bangarori da Kayan aiki:
  B1 = 9-volt batirin Alkaline S1 = SPST on-off ማብsa J1 = Jack don dacewa da (naka) na USB mai karɓar ANT1 = lesanjin bulalar bulalar (hawa dutsen), waya, sanda tagulla (kimanin 12 ") MISC = kayan PCB, shinge, mai riƙe baturi, karfen baturin 9V, da sauransu. 

Eriyawan na iya kasancewa kusan komai; dogayen waya, tagar walgiyar tagulla, ko eriyar tarho wacce aka kubuta daga tsohuwar rediyo. Hakanan ana samun isassun kayan maye gurbin Telescopic don radiyo transistor kuma ana samun su daga yawancin masu sayarda kayan lantarki da masu siyarwa.

Ginin:
Amplifier na samfurin samfurin suna amfani da kwamiti mai kewaye-duba (duba ƙasa). Amplifier din za'a iya tara shi a jikin katako mai lalacewa (vero board), amma saboda akwai wasu lura da yanayin, muna bada shawara sosai cewa ka ƙirƙiri wani kwamiti mai buga rubutu (PCB) don kyakkyawan sakamako.

PCB Bangarori-Layout
An nuna hoton zane-ɓangare na sassan a cikin hoto. 2. Lura cewa kodayake ƙarancin batirin (ƙasa) an komar da shi zuwa kwamatin PC, fitarwa-jack J1 yana da alaƙa da majalisa. Haɗin ƙasa tsakanin kwamatin PC da majalisa an yi shi ne ta fuskokin ƙarfe ko sararin samaniya waɗanda ake amfani da su don hau kan kwamatin PC a cikin zangon. Shin * BA * canza filastik filastik ko sararin samaniya saboda ba zasu samar da haɗin ƙasa tsakanin kwamatin PC ba, majalisa, da J1. Idan ka yanke shawarar amfani da sandar filastik don ɗaukar amplifier, tabbatar cewa an dawo da haɗin ƙasa na J1 zuwa ƙasa da ke gudana a saman allon PC-board.

Tenaukar eriya ta lankwamewa a tsakiyar hukumar PC. Daga gefen bangon jirgi, wuce tafin dutsen sa ta hanyar rami a cikin kwamatin PC sannan sai ya sayar da abin sawa a allon tafin. Don ɗaukar hoto da goyan baya, muna amfani da kwancen roba ko roba tsakanin eriya da rami a murfin majalisa wanda eriyar ta wuce. A takaice, za a iya sauya salo da dama na tef mai walƙiya mai kyau wanda aka ɗora akan shagon eriya don ɗanɗarin roba.

Idan ka yanke shawara don yin tanadi don eriyar waya, shigar da madaidaiciyar hanyar hanyoyi 5 akan majalisa. Sannan, tabbatar an haɗa ɗan gajeren waya tsakanin falon bangon eriya da maƙullin maƙullin.

Gyare-gyare:
Idan kuna da sha'awar ƙaramin mita fiye da 1-30MHz, za'a iya maye gurbin resistor R1 tare da da'irar tankin LC da aka kunna zuwa tsakiyar kewayon da ake so. LC kewaye zai kuma inganta ƙin siginar siginar a waje da yawan sha'awarku, amma ku tuna cewa ba zai inganta ribar amplifier ɗin ba.

Idan sha'awarku ta musamman ita ce ta sauƙaƙa-sauƙaƙa (VLF), ƙarar amplifier na ƙarancin mitar za a iya inganta ta haɓaka ƙimar capacitors C1 da C3. (Dole ne kuyi gwaji tare da dabi'u.)
Kodayake baturin 9-volt shine tushen wutar lantarki da aka ba da shawarar, amplifier din yakamata yayi aiki sosai ta amfani da 6-15 volts. A cikin majalisar ministocin da aka kammala, ta amfani da baturin 9-volt azaman wutar lantarki, an nuna shi a cikin siffa 3.

Bangarori-Layout
Shirya matsala:
Ana nuna voltiti na wutar lantarki mai nauyin 9-volt a cikin zane mai hoto schemat 1. Idan volt din dinka ya banbanta sama da kashi 20% na wadanda suke cikin tsari, gwada canza dabi'un juriya don samun karfin gwargwado. Misali, idan wutan lantarki ya fadi a fadin matakan R8 kawai 0.3 volt, dole ne ka rage darajar R4 (ainihin darajar ya rage a gareka ka tantance) domin kara karfin Q3 na tushe da mai tattarawa a halin yanzu.

Kadai mai mahimmanci voltages sune waɗanda ke tsaran R3 da R8. Yin aiki ya zama mai kyau idan har suna kusa da dabi'un da aka nuna akan zane mai ƙididdigewa.

Tunda kusan ba shi yiwuwa a auna ƙarfin lantarki daga ƙofar zuwa asalin (VGS) na FET, zaku iya auna ƙarfin lantarki wanda yake gudana a ƙasan R3, saboda daidai yake da VGS. Daidaita darajar R3 daidai da haka, idan ƙarfin lantarki ba ya cikin kewayon 0.8-1.2 volts.

gazawar:
Amfani da wannan amplifier sama da 30 MHz ba ya bada shawarar saboda rage riba mai yawa. Duk da yake aiki sama da 30 MHz za a iya cika ta ta amfani da da'irori masu motsi a maimakon abubuwan ɗauka don resistive, gyare-gyare ya fi ƙarfin wannan labarin.

Kula da hankali lokacin kula da FET (Q1). Imani da aka saba da shi shine cewa FET's sune na'urorin CMOS basu da matsala daga lalacewa ta ƙaranci bayan an saka su a cikin da'ira, ko kuma bayan an ɗora su a kwamiti na PC. Kodayake gaskiya ne ana kiyaye su sosai daga lamunin wutar lantarki lokacin da aka sanya su a cikin da'ira, amma har yanzu suna iya yin rauni ta hanyar lalata; saboda haka kar taɓa taɓa eriyar kafin cire kanka zuwa ƙasa ta taɓa wasu abubuwa na ƙarfe.

Hakkin mallaka da Credits:
Source: "Kundin gwaje gwaje na RE", 1990. Hakkin mallaka © Rodney A.Kreuter, Tony van Roon, Magajin Gidan Rediyo na Gidan Rediyo, da Gernsback Publications, Inc. 1990. An buga ta ne da izini a rubuce. (Bugawar Gernsback da Gidan Rediyo na Rediyo ba su cikin kasuwanci). Sabunta bayanan takaddun gyare-gyare & gyare-gyare, duk zane-zane, PCB / youtaddamarwa da Tony van Roon ya zana. Sake bugawa ko daukar hotuna ta kowace hanya ko nau'ikan wannan aikin ta haramtacciyar doka ta hakkin mallaka ta duniya.