Ngā Tohutohu mō te Hanga i tētahi Reo Irirangi me te Tairongo Nui
He moemoeā te hanga i tētahi reo irirangi he tino aro ki te oro, he mea hoki nā te mea ka taea e ēnei taputapu te hopu i ngā tohu ngoikore e uaua ana ki te whakarongo—hei tauira, ngā pāhotanga FM tawhiti, ngā whakawhitiwhiti reo irirangi amateur, ngā tohu rānei mai i ngā tuku reo irirangi iti-mana. Ko te aro ki te oro tonu e pā ana ki te kaha o te kaiwhiwhi reo irirangi ki te whiwhi tohu i ngā taumata mana iti, me te whakaputa tonu i te oro mārama. Heoi, kāore e ranea te aro ki te oro anake: ko te reo irirangi he tino aro ki te oro engari he iti te whiriwhiri ka hinga i te pokanoa me ngā tohu tata. Nō reira, ka matapakihia e tēnei tuhinga ngā tohutohu nui mō te whakataurite i te aro ki te oro, te whiriwhiri, me te mārama o te oro.
1. Kia Mārama ki ngā Take Whakatau o te Tairongo
He maha ngā āhuatanga matua e pāngia ai te aro o te reo irirangi: te kounga o te pūihi, te haruru porowhita, te whakanui i te atamira RF/IF, me te hoahoa tātari. I roto i te mahi, he maha ngā wā ka aro te hunga tīmata ki te whakanui ake i te whakanui, engari ko te whakanui ake i te whakanui me te kore e whakahaere i te haruru me ngā tātari ka kino ake ngā hua. Ko te whāinga pai ko te whakaiti i te papa haruru o te kaiwhiwhi me te pupuri tonu i te whakanui rawaka me te pumau.
2. Kōwhiria te Hanganga Kaiwhiwhi Tika
He maha ngā momo hoahoanga o te kaiwhiwhi: TRF (Tuned Radio Frequency), super-regenerative, direct conversion (homodyne), me te superheterodyne. Mō te tairongo me te pumau teitei, ko te superheterodyne tonu te whiringa tino noa nā te mea he wāhanga IF (Intermediate Frequency) tōna e āhei ai te whakanui teitei me ngā tātari koi ake.
– He māmā te TRF engari he uaua ake te pupuri i te pumau me te whiriwhiri i ngā auau teitei.
– He tino tairongo pea te tahuritanga tika, engari ka pāngia e ngā raruraru ngunguru, te DC offset, me te "oro kore-pao" mēnā kāore i te tika te hoahoa.
– He tino pai ngā Superheterodynes ki te whiriwhiri, ā, he ngāwari hoki te whakapai ake, inā koa mā te whakamahi i tētahi tātari IF pai.
Ki te hiahia koe ki te whakapāho reo irirangi FM, he tino tairongo hoki ngā waeine kaiwhiwhi IC hou; engari ki te hiahia koe ki te ako me te hoahoa i tāu ake, he ara ako whai rawa te superheterodyne.
3. He mea nui ake te pūihi tika i te "maramara pai" noa iho
Ko ngā pūihi te mea matua e whakatau ana i te whiwhinga tohu tawhiti. Anei ētahi tohutohu:
1. Whakatikatikahia te roa o te pūihi ki te auau mahi.
Mō te FM (88–108 MHz), ko te roa o te pūihi 1/4-ngaru he tata ki te 75 cm (i runga i te tere). He rerekē ngā tātaitanga mō ētahi atu roopu VHF/UHF.
2. Whakamahia he taura coaxial pai hei whakaiti i ngā ngaronga, inā koa mēnā kei tawhiti te pūihi i te reo irirangi.
3. Whakaturia te pūihi ki te teitei rawa e taea ana, kia matara atu i ngā pūtake haruru (ngā rihi, ngā urutau whakawhiti, ngā pouara).
4. Tāutahia he taurite tika mēnā ka taea (hei tauira, 50 ohms, 75 ohms rānei, kei te pūnaha). Ka taea e te pūihi kāore i te ōrite te whakaata i ngā tohu, ā, ka whakaiti i te pai o te mahi.
He maha ngā wā ka pai ake te hiko o te reo irirangi me te pūihi tika i tētahi reo irirangi "matatini" me tētahi pūihi taupua.
4. Whakaitihia te haruru mai i te Pūnaha Hiko
Ko te haruru o te pūtake hiko te hoariri matua o te aro. He maha ngā kaupapa reo irirangi e rahua ana, ehara i te mea nā te hē o te ara iahiko, engari nā te paru o te pūtake. Ko ētahi mahi whai hua:
– Whakamahia he kaiwhakahaere haruru iti kounga teitei, he LDO rānei, mō te wāhanga RF me te oscillator.
– Tāpirihia he pūnga wetewete tata ki te pine IC/transistor (he huinga o te uku 100 nF + 10 µF electrolytic/tantalum).
– Wehea ngā rārangi tuku i waenga i ngā wāhanga oro me ngā wāhanga RF i ngā wā katoa e taea ai.
– Ki te whakamahi koe i tētahi urutau whakawhiti, whakaarohia te whakamahi i tētahi tātari LC, i tētahi pākahiko rānei i te wā whakamātautau tuatahi kia mōhio ai ehara i te pokanoa o te tuku hiko te pūtake o te raruraru.
5. Whakamahia he LNA Pai, he Atamira RF Mua rānei (Engari kaua e nui rawa te whakamahi)
Hei whakanui ake i te aro, ka taea e koe te tāpiri i tētahi LNA (Low Noise Amplifier) ki te pito o mua. Heoi, he mea nui tēnei hei whakatūpato:
– Kōwhiria he transistor, he IC rānei he iti te haruru.
– Me whakarite kei reira he tātari whakawhiti-roopu i mua, i muri rānei i te LNA kia kore ai e whakanuia e te LNA ngā tohu kotiti katoa (ka puta ai te whakawhitiwhitinga).
– Kia tūpato ki te whānuitanga hihiri. Mena he nui ngā tuku hiko kaha i roto i tō taiao, ka taea e te LNA kaha rawa te uta i te kaiwhiwhi.
Ko te mea tino pai, ka whakaratohia e te atamira RF o mua te whiwhinga e tika ana me te pupuri tonu i te raina.
6. Arotauhia ngā Tātari mō te Kōwhiringa me te Ma o ngā Tohu
Kāore he tikanga o te aro nui ki te mea kua huna te tohu e te pokanoa. Nō reira:
– Tāpirihia he tātari whakawhiti-roopu ki te auau ūnga (hei tauira, FM 88–108 MHz).
– Mō ngā kaiwhiwhi superheterodyne, whakamahia he tātari IF pai (tātari uku mō te FM, tātari tioata rānei mō te HF/SSB).
– Mā te hoahoa tātari whānui rawa ka taea te whakauru ngāwari i ngā tohu, engari ka puta hoki te haruru me ngā tohu tata.
Ko te mea nui he whānui tātari e tika ana hei whakauru i ngā mōhiohio (oro) engari ka whakakorehia tonutia ētahi atu hongere.
7. He mea tino nui te tahora PCB me te whenua
I ngā auau teitei, he rite te hiranga o te tahora ki te hoahoa. Ngā tohutohu whai hua:
– Whakamahia he papa whenua whānui.
– Whakapotohia, kia tika hoki ngā ara RF, karohia ngā takahuri nunui.
– Wehea ā-tinana ngā wāhi RF, IF, oscillator, me te oro.
– Whakamahia he parepare (he kēne/pouaka whakarewa) mō te oscillator, mō ngā wāhanga RF rānei mēnā e tika ana.
– Kia tino pakari te hononga whenua, ā, kaua e "haereere" ki tawhiti rawa, nā te mea ka mahi hei pūihi e hopu ana i te haruru.
He maha ngā reo irirangi ka "tairongo ake" mā te whakapai ake i te tahora me te hononga whenua.
8. Te Pūmautanga o te Oscillator: Te Mea Matua hei Ārai i te Ngaro Ngāwari o ngā Tohu Ngoikore
Hei whiwhi i ngā tohu ngoikore, me pumau te auau o te oscillator. Mēnā ka hē te oscillator, ka rerekē te tohu, ka ngaro rānei. Anei ngā mea ka taea e koe te mahi:
– Whakamahia ngā wāhanga kounga teitei (ngā pūnga NP0/C0G mō ngā ara iahiko whakakorikori).
– Me whakarite kia pai te tātari o te pūnga orooro.
– Whakamahia he pūwhakakotahi PLL mēnā ka taea, he pumau ake hoki i tētahi oscillator LC noa iho.
– Whakaitihia te awe o te pāmahana mā te whakanoho i ngā wāhanga kia ma, me te whakarato hoki i te hauhautanga e tika ana.
9. Te Whakanui IF me te AGC (Mana Whakanui Aunoa)
Ko te wāhanga IF te wāhi ka taea e koe te tāpiri i te nui o te whakanui me te kore he raruraru nui ki te whakatauritea ki te RF tika. Heoi, me taurite ngā whakanui nui me te mana whakahaere:
– Whakatinanahia te AGC kia kore ai ngā tohu kaha e pakaru te oro, kia rangona tonutia ai ngā tohu ngoikore.
– Kōwhiria te whakanui maha-wāhanga kaua ki te wāhanga kotahi me te whakanui tino nui.
– Kia tūpato ki te ātete, ki ngā pūnga honohono, me te whānui o te hononga kia kore ai e tāpiri haruru, e tapahi rānei i ngā mōhiohio oro.
Mā te AGC pai ka "atamai" te reo irirangi, ka whakamarie hoki te whakarongo.
10. Whakatikahia te Wāhanga Ororongo: Ka taea te pohehe i te Haruru Ororongo hei Haruru RF
I ētahi wā ka hopukina te tohu, engari ka tangi haruru nā te mea he kino te whakakaha oro. Tohutohu:
– Whakamahia he op-amp, he IC oro rānei, he iti te haruru.
– Whakamahia he tātari oro pāpaku-iho hei whakaiti i te nui o te whiowhio.
– Te whakatakotoranga ara ororongo mai i te oscillator/RF.
– Kia tino mohio kei konatunatua te whenua oro ki te whenua RF (whakamahia ngā tikanga whenua whetu, te wehewehe whenua rānei mēnā e tika ana).
Mā te oro ma ka pai ake te rongonga o te reo irirangi nā te mea ka mārama ake te rangona o ngā tohu iti.
11. Whakamātauria mārire, ā, whakamahia ngā taputapu ine māmā
Ko te whakanui ake i te aro o te kiri ka tino whai hua mā te whakamahi i ngā tikanga whakamātautau e whai ake nei:
– Whakamātauria te whiwhinga mā te whakamahi i tētahi pūtake tohu ōrite (he tuku iti, he whakaputa tohu, he teihana tohutoro rānei).
– Kia mōhio ki ngā panoni ina whakakapia ngā pūihi, ina tāpirihia ngā tātari, ina nekehia rānei ngā raina whenua.
– Mēnā kei te wātea, whakamahia he dongle SDR hei whakataurite i te whānuitanga: ka taea e koe te kite mēnā kei te puta mai te pokanoa mai i te taiao, mai i te ara iahiko rānei.
Mā te huarahi taahiraa-i-te-taahiraa, e kore koe e ngaro i te wā e whakatika ana i ngā wāhanga ehara i te raru.
12. Āta karohia ngā Pūtake Whakararuraru e Huri Ana i a Koe
Kī tonu te taiao hou i te haruru: ngā rama LED utu iti, ngā urutau whakawhiti, ngā pouaka whakaata, ngā pona, tae atu ki ngā taura USB. Ki te hiahia koe kia tino tairongo tō reo irirangi:
– Kia matara atu te reo irirangi i ngā taputapu matihiko i te wā whakamātautau.
– Whakamahia ngā rawhi ferrite ki ngā taura hiko mēnā e tika ana.
– Me whakarite kia tika te katinga o te pouaka reo irirangi mēnā kei te whakamahi koe i tētahi anga whakarewa hei āwhina i te tiaki.
I ētahi wā ko te "whakapai ake nui" ko te neke i te reo irirangi ki tētahi wāhi marino.
Te Katinga
Ehara i te mea ko te tāpiri noa i te whakanui i te kaha te hanga i tētahi reo irirangi he tino aro; engari ko te pehi i te haruru, te whakapai ake i te pūihi, te whakarite i te tātari me te whakatakotoranga tika, me te pupuri i te pumau o te orooro. Ki te whakatauritea e koe te aro ki te whiriwhiri me te kounga oro, ka nui ake te pai o ngā hua: he reo irirangi ka taea te hopu mārama i ngā tohu ngoikore me te kore e ngāwari te whakararuraru.
Ki te hiahia koe, ka taea e au te whakarite i tēnei tuhinga i runga i te momo reo irirangi e hiahia ana koe ki te hanga (pāho FM, HF/SSB, VHF amateur, kaiwhiwhi IC/kōwae rānei), tae atu ki te taumata uaua o te kaupapa (mai i te tīmatanga ki te matatau).
