Ingxenye yokuba umshayeli womsakazo we-ham ukunikeza ukuxhumana ngezikhathi zezimo eziphuthumayo. Ngosuku oluzayo lwe-Ohio NVIS Antenna, ngikhethe ukubheka izimpondo ze-NVIS. Ama-antenna e-NVIS, abuye abizwe ngokuthi ama-Near Event Vertical Vertical Skywave antenna ane-engeli ephezulu yemisebe. Okuthile ku-oda lama-degree angama-60, kuya ku-90 degrees ngqo. Ngokungafani namasiginali we-UHF ne-VHF, avame ukuba nobubanzi bamamayela angu-50 anothi lwe-yagi oluphezulu, kanye nothi lwe-NVIS lwenzelwe ukuxhumana ngezinhlobonhlobo zamamayela angu-75-- 500. Kwesinye isikhathi i-antenna ye-NVIS ibizwa ngokuthi "i-heater yamafu" njengoba ihambisa imisebe yayo eminingi phezulu kune-antenna evamile.
Umbono onothi lwe-NVIS ukukhipha amandla amaningi ngangokunokwenzeka nge-engeli ephezulu futhi uveze nokuthi abonakale ku-ionosphere. Ngokombono osebenzayo, ukuxhumana kwe-NVIS kwenzeka ngo-10 MHz nangaphansi. Enye ingxenye yothi lwe-NVIS yiqiniso lokuthi iphansi kakhulu phansi. Lezi zinsiza zikhipha isignali nge-engeli ephezulu, kanye nokwenza kube lula ukuyikhulula. Kunemibono eminingi mayelana nokuphakama okusebenzayo kwe-antenna ye-NVIS, nokho, wonke umuntu ubonakala ehlala cishe. 1/8 wavelength ngaphezu komhlabathi futhi ngokuvamile ngaphansi kakhulu.
Bengifuna i-antenna ye-NVIS ephathwayo, elula ukusethwa, kanye nezindleko eziphansi (kunjalo). Ekugcineni, ngase nginakho konke enginakho. Nge-antenna yami ye-NVIS, ngaqala ngendawo yami yamamitha angu-2 yemoto yami. Ngemva kwalokho, kwakumane kuyindaba yokunamathisela intambo ye-quarter-wave endukwini ye-mag, bese umane ubophe intambo ibe isicaba isuka endaweni ye-mag iye esihlahleni noma esigxotsheni sohlobo oluthile.
Ngifisa ukukwazi ukuxhuma endaweni ye-mag ngokushesha. Ngenze isiqeshana sebhethri esilayishwe entwasahlobo. Kodwa hhayi nje noma yisiphi isiqeshana sebhethri. Empeleni ibinamandla okuma idonse iqonde ngaphandle kokuphuma ku-mag mount antenna. Engikucabange kukhonjisiwe esithombeni esibhalwe ngezansi:
Kwesinye isikhathi lezi zibizwa ngokuthi Iziqeshana zebhethri le-Crocodile, noma iziqeshana zokuhlola. Ngakhetha okwami esitolo sendawo se-NAPA sezingxenye zezimoto. Kunamasayizi ambalwa ahlukene. Uzodinga ukwenza isiqiniseko sokuthi imihlathi ivuleka ngokwanele ukuze uvikeleke kusisekelo sokufakwa kwe-mag ozokusebenzisa.
Ngakho-ke okwamanje kuyindaba elula nje yokuxhuma intambo kulesi sibani. Ngikhethe ukukhipha isikulufu ngemuva kwe-clamp kanye nokushelela ikhebula ngembobo bese ngidayisela ikhebula ku-clamp. Lezi zinsiza zinikeza ukuqina okwengeziwe njengoba leli lunga lizoba ngaphansi kokucindezeleka okuthile.
Ngezansi isithombe se-antenna yami yeselula ye-NVIS phezu kweJeep yami sisebenzisa indawo ye-mag:
Mayelana nobude bentambo okufanele isetshenziswe, isibonelo sami, ngisebenzisa amamitha angu-40 osukwini lwe-Ohio NVIS Antenna. Umuntu angakholelwa ngokuqinisekile ukuthi ifomula yakudala yekota ye-wavelength eqondile ingasebenza nakanjani. Nokho, lokho kubonakala kungenalo iqiniso. Ngokubheka ukuthi le-antenna ye-NVIS imfushane kakhulu futhi iseduze nemoto, umzamo wami wokuqala usebenzisa ifomula 234/ freq. ukuthola usayizi wentambo kunginikeze ukudlidliza okungu-8.6 MHz. Ngendlela, ukuba ne-MFJ antenna analyzer kusiza kakhulu ngale nqubo. Ngakho ngihlome ngalolu lwazi, ngenza ukucabanga emuva futhi ngacabanga okwami njalo ukuze ngibale ubude obufanele balolu hlobo lwe-antenna ye-NVIS. Lokho akusho ukuthi lokhu kuphonswe etsheni, nokho yilokhu okungisizile, okungenani ngalesi sikhathi.
Ifomula entsha engiyiqambile yilena elandelayo:
Ubude (ft.) = 261/ F (mhz).
Ngezansi kunesithombe esengeziwe se-antenna yami ye-NVIS esetshenziswe ngokuphelele. Qaphela ukuthi ekugcineni ngisebenzisa izigxobo zetende ze-fiberglass ezingu-2 4 ft engazibamba endaweni yangakini.
Imiphumela yami yokuqala ibonisa ukuthi ibonakala isebenza kahle ku-antenna ye-NVIS. Ngizophinde ngihlanganise nomlenze wamamitha angu-75 ekusetheni esikhathini esizayo futhi. Leyo yindaba elula yokusabalalisa intambo, okuhlanganisa ne-clamp yokuxhuma ekufakweni kwe-mag, kanye nokukhulula.
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