Ngā Tohutohu me ngā Tinihanga mō te Hanga i tētahi Reo Irirangi me tētahi Pūihi o Waho
He kaupapa hikohiko ngahau, he kaupapa ako hoki te hanga i tō ake reo irirangi. Haunga te whakangungu i te tika me te mārama ki ngā ara iahiko, ka whakaratohia hoki e tēnei kaupapa he wairua harikoa motuhake ina rangona mārama te oro e puta mai ana i te taputapu kua huihuia. Ko tētahi o ngā mea tino whai mana ki te kounga o te whiwhinga reo irirangi ko te pūihi. Nō reira, ko te whakamahi i te pūihi o waho te mea pai rawa atu hei whakanui ake i te aro, hei whakaiti i te haruru, hei whakawhānui ake i te whānuitanga o te tohu. Ka matapakihia e tēnei tuhinga ngā tohutohu me ngā tinihanga mahi mō te huihui i tētahi reo irirangi me te pūihi o waho mō tētahi reo irirangi ma, haumaru, me te mahi pai rawa atu.
1. Whakatauhia te momo reo irirangi hei huihui
I mua i te whiriwhiri i ngā wāhanga me ngā pūihi, me whakatau tuatahi te momo reo irirangi e hiahia ana koe ki te hanga. Ko te tikanga, ka wehea ngā kaupapa reo irirangi kāinga ki:
– Te reo irirangi FM (88–108 MHz): te mea tino rongonui, he ngāwari te tiki i ngā wāhanga, he tino māmā te pūihi.
– Reo irirangi AM (MW): he mea whakamere mō te whakamātautau, engari he tairongo ake ki te pokanoa hiko mai i ngā taputapu whare.
– Te Reo Irirangi Ngaru Poto (SW): he tawhiti ake te awhe, engari me whai pūihi me ngā ara iahiko tika ake.
Mō ngā tīmatanga, ko te reo irirangi FM te kōwhiringa tino māmā ki te whakamahi nā te mea he maha ngā kōwae FM kua oti te hanga (hei tauira, ngā kōwae whakahāngai, ngā IC reo irirangi rānei) ka taea te whakakotahi me te whakakaha oro.
2. Kōwhiria he Kōwae Reo Irirangi Pūmau, he IC rānei
Mena he tere ngā hua me te iti o te rapurongoā tōu whāinga, whakamahia he waeine reo irirangi kua whakamātauhia. Ko te tikanga kua whai waeine reo irirangi (RF) te wāhanga auau reo irirangi, te oscillator, me te demodulator. Ko tāu noa he tāpiri i tētahi pūtake hiko ma, ngā mana whakahaere (ngā pātene/encoder), me tētahi whakakaha oro.
Ki te hiahia koe ki te ako atu, ka taea e koe te hanga mā te whakamahi i ngā IC reo irirangi rongonui. Heoi, kia tino whai koe i te pepa raraunga, inā koa mō te tahora PCB, ngā pūnga hiko whakawhiti, me ngā tātari.
He tohutohu nui: he maha ngā raruraru o ngā reo irirangi i hangaia i te kāinga ehara i te mea nā ngā "IC kino", engari nā te tahora paru, te roa rawa o ngā ara iahiko, te whenua ngoikore rānei.
3. Kia Mārama ki te Tūranga o ngā Antenna o Waho
Ka hopukina e te pūihi o waho ngā ngaru reo irirangi ka tukuna ki te tāurunga RF o te reo irirangi. Ko ōna painga i runga i te pūihi o roto (he taura poto kei roto i te pouaka) ko:
– He tohu kaha ake, he tohu pumau ake
– He māmā ake te whakanoho (whakaara, hurihuri, nekehia kia matara atu i ngā pūtake haruru)
– Ka taea te whakamahi i ngā pūihi me ētahi āhuatanga: dipole, ground plane, yagi, me ētahi atu.
Heoi anō, ka taea hoki e ngā pūihi o waho te noho hei "kuaha" mō te pokanoa mēnā he kino te taura, he hē rānei te tāutanga.
4. Kōwhiria te momo pūihi e tika ana
Mō te reo irirangi FM, ko ētahi kōwhiringa pūihi o waho he ngāwari ki te hanga:
1. Pūihi rua-ngaru ½
Koinei tētahi o ngā mea tino whai hua, tino māmā hoki. Ko te roa katoa o te dipole FM e tata ana ki:
– Tātai tere: roa (mita) ≈ 150 / auau (MHz)
Hei tauira, mō te 100 MHz: 150/100 = 1,5 mita (katoa), ko te tikanga he 75 cm te roa o ia waewae.
2. Pūihi Papa Whenua
He pai mō te tāutanga o waho. Ko te tikanga he poutū, ko ētahi he poutū.
3. Pūihi Karuārai o Waho
Ko te huarahi māmā rawa, mono noa i te hononga ka whakamahia he pūihi karu tiro pērā i te reo irirangi kawe.
Mō te AM, he tokotoko ferrite, he koropiko rānei te pūihi, engari ka taea tonu e koe te tāpiri i tētahi pūihi waea roa me tētahi ara iahiko e ōrite ana hei ārai i te taumaha rawa.
5. Whakamahia ngā Taura me ngā Hononga Tika
Ko tētahi hapa noa ko te whakamahi i tētahi taura hei pūihi o waho. Mō te FM, whakamahia te taura coaxial (hei tauira, RG-58, RG-59 rānei). Ka āwhina te taura coaxial ki te whakaiti i te pokanoa nā tōna parenga.
Ngā hononga e whakamahia whānuitia ana:
– SMA (he mea noa i ngā kōwae RF hou)
– BNC (whai hua, kaha hoki)
– Momo-F (i runga i ngā pouaka whakaata i te nuinga o te wā)
– Ngā pūrua tīwiri (e whakaaetia ana, engari he ngāwari ki te haruru mēnā he roa te taura)
Tinihanga: mēnā he papa pūihi anake tō kōwae, kāore he hononga, ka taea e koe te tāuta i te hononga ki te pouaka panera, kātahi ka hono atu ki te kōwae mā te whakamahi i tētahi taura coaxial poto.
6. Kia aro ki te aukati me te taurite
He ātete motuhake tō ngā pūihi me ngā whakaurunga reo irirangi (he maha ngā wā he 50 ohms, he 75 ohms rānei). Ka kore e pai te tuku tohu mēnā kāore i te ōrite te ātete. Mō ngā kaupapa kāinga, kāore he take kia tino tika rawa, engari anei ētahi mahi māmā:
– Whakamahia he pūihi coaxial 75 ohm mō ngā pūihi dipole TV/FM noa.
– Mena he 50 ohm te motuhaketanga o te waeine reo irirangi, whakamahia ngā taura me ngā hononga 50 ohm i ngā wā katoa e taea ai.
– Āta karohia ngā hononga maha me ngā taura roa rawa, kāore he take.
Ehara i te mea ka whakapai ake te taurite pai i te tohu anake, engari ka whakaitihia hoki ngā whakaata me te haruru pea.
7. Me Ma, me Pūmau hoki te Pūnaha Hiko
He tino tairongo ngā reo irirangi ki te haruru o te pūtake hiko. Mena kei te whakamahi koe i tētahi urutau whakawhiti utu iti, ka pāngia koe e te haruru whiowhio, te haruru, te pakū rānei, inā koa ka ngoikore te tohu.
Ngā tohutohu mō te tuku hiko:
– Whakamahia he kaiwhakahaere hiko pai me ngā pūnga tātari e tika ana.
– Tāpirihia he pūnga ārai hiko (hei tauira, 100 nF tata ki te IC).
– Ki te whakamahi koe i tētahi whakakaha oro, wehea ngā rārangi whenua oro me te RF, kātahi ka honoa ki te pūwāhi kotahi (whenua whetu).
Tinihanga: ka tino whakaitihia te haruru mā te tāpiri noa i te pūnga hiko 100 nF + 10 µF ki te taha o te waeine reo irirangi.
8. Tahora me te Tūāpapa: Te Kī ki tētahi Reo Irirangi "Taurongo"
Kāore ngā ara iahiko RF e pai ki ngā taura roa me ngā whakatakotoranga paru. Mena kei te whakamahi koe i tētahi PCB poka, ngana kia poto ngā wāhanga RF.
Ko ētahi tinihanga whakatakotoranga:
– Whakatakotoria te waeine reo irirangi ki te hononga pūihi kia tata rawa atu.
– Whakamahia he papa whenua ina hanga ana i tāu ake PCB.
– Puritia te wāhanga RF kia matara atu i te wāhanga whakakaha hiko oro.
– Wehea te ara tohu oro mai i te ara RF.
Ki te huihuia e koe ki roto i tētahi pouaka whakarewa, ka āwhina te pouaka ki te tiaki i te taura, engari kia tika te hononga whenua, ā, kia kore ai e hanga he koropiko whenua.
9. Ka Whakatauhia ngā Hua e te Tūnga o te Pūihi
Ahakoa te pūihi pai rawa atu, kāore pea e tino pai mēnā ka hē te whakanoho. Whakamātauria ēnei rautaki:
– Whakaturia te pūihi ki te teitei rawa e taea ana, hei tauira, tata ki te matapihi, ki waho rānei o te whare.
– Puritia kia matara atu i ngā pouara Wi-Fi, ngā rihi hiko, ngā rama LED, me ngā taputapu whakawhiti hiko.
– Hurihia te pūihi dipole kia kitea ai te ahunga tohu pai rawa atu.
– Kaua e tāpirihia te pūihi ki ngā anga whakarewa nunui, ka taea hoki e ia te whakarerekē i ōna āhuatanga.
He mahi tinihanga māmā noa iho: he maha ngā wā ka whai hua ake te hiki ake i te pūihi 1–2 mita noa iho i te whakakapi i te waeine reo irirangi.
10. Tāpirihia te Parenga me te Haumarutanga
Mena kei waho te pūihi o waho, kia tupato ki te haumaru:
– Whakamahia he pouaka ātete ki te huarere mō ngā hononga.
– Kia tino mohio kāore te taura i pakarukaru, ā, kia ngāwari hoki te tango i te taumahatanga.
– Whakaarohia ngā ārai uira māmā (ngā ārai uira) mō ngā tāutanga tuturu.
– Momotuhia te pūihi i te wā e pā mai ana te uira mēnā kāore i te rawaka te whenua o tō tāutanga.
Mō te whakamahinga o roto, kia tino kaha te hononga, ā, kia kore e ngawari te kume e te taura.
11. Te Whakamātautau me te Whakatikatika mā te Tikanga Hipanga-ā-Tau
Ki te kore tō reo irirangi e mahi pērā i te mea e tumanakohia ana, kaua e ngana tonu ki te wetewete i ngā mea katoa. Whakamātauria i ia taahiraa:
1. Kia tino tika te hiko whakauru kia rite ki ngā whakaritenga.
2. Tirohia mēnā kei te mahi te whakakaha oro (whakamātauria ki tētahi atu pūtake oro).
3. Tirohia te waeine reo irirangi: kei te puta he putanga oro ina rapu ana i ngā teihana.
4. Whakamātauria tētahi atu pūihi: he taura poto, he pūihi dipole, he pūihi karu rānei.
5. Nekehia te tūranga o te reo irirangi/pūihi kia kore ai he raruraru tohu.
Mena kei a koe ngā taputapu pēnei i te mita maha me te oscilloscope māmā, ka tino māmā ake te tukanga rapurongoā.
12. Ngā Whakapai ake hei Whakamātau
Kia mahi te reo irirangi, ka taea e koe te whakapai ake i te mahi mā te tāpiri i ētahi atu mea:
– Te pūihi whakapūmau FM-motuhake (LNA) (kia tūpato, ka nui rawa pea te uta mena he tino kaha te tohu).
– Tātari Bandpass hei whakaiti i te pokanoa ki waho o te roopu.
– He pūwhakamātautau reo irirangi pai ake, he kōwae rānei me te āhuatanga RDS.
– Whakakaha oro Akomanga D mō te tino whai hua me te tangi nui ake.
Me mahi takitahi ngā whakapai ake kia mōhio ai koe ko ēhea ngā huringa ka nui te pānga.
Te Katinga
Ehara i te mea ko te whakapiripiri noa i ngā wāhanga te hanga i tētahi reo irirangi me tētahi pūihi o waho; engari me mārama hoki ki ngā mātāpono taketake o te whiwhinga tohu, te whakahaere haruru, me te hiranga o tētahi tahora ma me te pūtake hiko. Mā te pūihi o waho tika—kua tāutahia me te taura coaxial pai, ngā hononga ma, me te tūnga rautaki—ka taea te whakapai ake i te kounga whiwhinga. Mā te whai i ngā tohutohu me ngā tinihanga i runga ake nei, ka taea e koe te hanga i tētahi reo irirangi e mahi ana, engari e tuku ana hoki i te whiwhinga pai, mārama, me te pumau.
Ki te hiahia koe, ka taea hoki e au te āwhina i a koe ki te waihanga i tētahi putanga hangarau ake o tēnei tuhinga (me ngā hoahoa ngāwari, ngā rārangi wāhanga, me ngā mahi huihui mō te reo irirangi FM) e whakaritea ana mō tō taumata: tīmatanga, waenga, matatau rānei.
