Yakha i-Phasing Harness ye-Piling Antennas

Kamuva nje, emsebenzini, ngibe nethuba (noma imfuneko) yokwenza ihhanisi lezigaba le-antenna ene-two-bay. Nokho, ngaba nenkinga. Ngithole ku-inthanethi eminyakeni embalwa edlule ukuthi ngingakwenza kanjani lokhu esimweni sami esithile se-antenna, namuhla iwebhusayithi yayingasekho! Ngakho kwadingeka ngizibonele ngedwa. Ngemva kwamahora amaningi ngibheka amanothi ami (ampofu kakhulu), ngiwatholile.

Enganginakho kwakuyisethi yezimpondo eziyindilinga ezine-polarized ezazizosungulwa njengohlelo lwama-antenna amabili. I-antenna ngayinye yayinokumelana kwe-100 ohms. Ngezansi yilokho engiqhamuke nakho, futhi kubonakala kusebenza.

Emgqeni wokudlulisa, njenge-coax, ukungezwani komthwalo kuziphindaphinda njalo ngesigamu se-wavelength. Ngenxa yokuthi uthi lwezimpondo lushunwe lube ngama-ohm angu-100 lapho kudlidliza, engidinga ukukwenza nje ukunciphisa ubude be-coax ngokuqondile bube kuhhafu we-wavelength ewuhhafu, futhi ngibuxhumanise ne-adaptha ye-Tee. Lokhu okwenziwayo kuthatha ama-impedances amabili we-100 ohm we-antenna ngayinye futhi kubekwe ngokufana komunye nomunye. Umphumela uyiphoyinti lokuphakelayo elingu-50-ohm, elingenza ngikwazi ukuxhuma i-coax yami engu-50-ohm ngokufanisa okulungile.

Nokho, kunenkathazo eyodwa. Lapho i-coax ikhiqizwa, kunokumelana okungu-10% ekuguquguqukeni kwejubane le-coax. Ngakho-ke mina ngikhathazekile, ukuthatha nje ukuguquguquka kwesivinini esikhululiwe kwe-coax kungase kukhathaze. Ngakho-ke ngidinga indlela yokulinganisa noma yokushuna osayizi abayimfihlo be-coax ukuze babe nokuphindaphinda kwe-wavelength ewuhhafu.

Kusetshenziswa umlando, ngezansi yisifanekiso esifana nesistimu ye-antenna ebengiyimisa. Izinto ezimbili ze-coax obekumele ngizinciphise zihlukaniswa njenge "Phasing Harness":

Ngakho-ke enganginakho kwakuyi-Belden 8237 RG-8-U Kind coax. Lokhu kunokuhlukahluka kwesilinganiso okungu-0.66 kanye nokuvinjelwa okuthile okungu-52 ohms. Ngakho-ke ngokususelwe kulezi zinombolo, kanye nezikhala phakathi kwamatheku amabili wezinti, ngikhethe ukusebenzisa usayizi we-coax ongamaphesenti angama-7 namashumi amahlanu ubude. Empeleni, lena indlela ende kakhulu ezidingweni zami, nokho lokho kulungile.

Nakhu engiqhamuke nakho, ngizolingisa zombili izimpondo ekudlidlizeni ngesixhasi esingasasebenzi esingu-100-ohm. Ngakho-ke ngazakhela eyami inkatho ye-dummy ngaphakathi kwesixhumi sowesilisa sohlobo lwe-N, kanye nangemuva kwe-adaptha yohlobo lwe-N yowesifazane. Ngokulandelayo, nginqume ubude beza obungamaphesenti angamashumi amahlanu e-coax kagesi ngisebenzisa ifomula yokunamathela:

L (amayintshi) = (5904 * VelFactor) / Freq. (mHz)

Lokhu kuzokunikeza usayizi wephesenti elilodwa lamashumi amahlanu ubude begagasi. Esimweni sami, ngikhethe ama-wavelengths angu-7 amaphesenti angamashumi amahlanu, ngakho ngandisa umphumela ngo-7, ngabe sengingeza i-15%. Le sayithi futhi yinde ngamabomu ukuze ngikwazi ukuyishuna ibe yimvamisa oyifunayo. Ngakolunye uhlangothi lwe-coax, ngibeke ichweba phezu kwalo. Esinye isiphetho isiphetho engizosikwa ngosayizi. Ngakho-ke kulokhu, ngifaka i-adaptha kuyo, nokho, angiyidayisi, okulungile ukulinganisa ubude bayo okwesikhashana.

Nasi isethulo sohlelo lwami lokuhlola ngisebenzisa i-MFJ-209 antenna analyzer:

Qala ukuhamba kwakho okujwayelekile uhambe kancane ngaphezu kokujwayelekile okufunayo, bese uqala ukubhulashi ubheke phansi. Njengoba ushuna imvamisa ehlukahlukene, ngokuqinisekile uzothola isici lapho i-SWR iya cishe koku-1 kuye koku-1. Ngokuvamile ngihambisa okujwayelekile izikhathi ezimbalwa ku-nadir ye-SWR kuzo zombili izinkomba. Lokhu kuqinisekisa ukuhlaziya okunembile kwemvamisa ye-coax. Yehlisa ukujwayela.

Okulandelayo, sika i-coax nge-intshi, bese uphinda izinyathelo ezingenhla phezulu kuze kube yilapho i-SWR icwilisa ngefrikhwensi efanayo njengoba izimpondo zakho zinamandla ngakho. Yenza lokhu kuzo zombili izinto ze-coax, ezakha i-harness ehlukanisayo.

Uma usuqedile ngazo zombili izingcezu ze-coax, njengamanje unehhanisi eliqediwe elicushwe ngendlela efanayo ncamashi yezimpondo zakho.

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