Iindlela zokwenza ii-eriyali ze-DVB-T2 zokufumana umabonakude wedijithali

Ukuba awufuni ukuthenga i-eriyali ye-DVB-T2 yeTV yedijithali , ungayenza ngokwakho usebenzisa izixhobo ezikhoyo. Ekubeni akukho luyilo olunokuthi lusebenze ngempumelelo kwiimeko ezahlukeneyo, kufuneka ukhethe eyona nguqulelo ifanelekileyo yesixhobo esenziwe ekhaya, kuxhomekeke kwimeko ethile.

Ii-Antenna ezilula

Ukuba kukho imfuneko engxamisekileyo yokwakha i-eriyali ye-DVB T2, kwaye uluhlu lwezinto eziphuculweyo zilinganiselwe, unokuhlanganisa isixhobo sokuqala ngokwakho.

“I-Tin” (in) i-eriyali

Idibanisa ngokukhawuleza kwaye kulula. Ukwamkela okulungileyo, udinga isignali ephezulu ngaphandle kwemiqobo. Impembelelo enkulu inokufumaneka kwiindawo ezisezidolophini nakwiidolophu ezincinci. Ukwenza udinga:

• iitoti zebhiya – 2 pcs.;
• i-screwdriver, iibholiti, izikrufu zokuzicofa;
• iplagi, intambo;
• ucingo lobhedu (iqhekeza elincinci);
• i-adhesive tape okanye i-insulating tape;
• iintonga zokhuni – 2 pcs.

Kwi-antenna, kuyimfuneko ukwenza isakhelo se-cruciform emthini. Emva koko senza la manyathelo alandelayo:

1. Senza imingxuma yeebholiti phakathi kwezantsi kweetoti.
2. Sisusa i-cable insulation ngaphandle kokuchaphazela i-contour yangaphandle, ilingana nobude kwiimbiza ezintathu + enye i-20 cm.
3. Silula ikhebula ngomngxuma omnye ukuya kwelinye, sibeka amathini ngeentamo zabo ngokufanayo. Silungisa ikhebula ekupheleni nge-bolt okanye i-self-tapping screw.
4. Silungisa ikhebula ukusuka emngxunyeni kunye nenxalenye yayo engenanto phakathi kweebhanki kunye nocingo.
5. Silungisa izimbiza nge-tape okanye i-insulating tape (i-turn turn yanele) kwibar yefreyimu, ebekwe ngokuthe tye.
6. Sifaka iplagi.

Xa ugoba, musa ukulimaza ikhebula, ngaphandle koko awuyi kufumana uphawu oluhle. Musa ukuphosa icandelo lekhebula elingenanto – unomda we-0.2 m.

Ngoku sinquma ixesha elifunekayo phakathi kweengqayi. Sidibanisa iplagi kwaye sihamba kunye nebar kuze kufike uphawu oluzinzile. Njengomthetho, umphumo omkhulu ufezekiswa kumgama we-7 cm ukusuka kwingqayi enye ukuya kwelinye. Emva koko, sibanamathisela ngokuqinileyo kwi-contour. Ukuba i-antenna isetyenziswe ngaphandle, kuyimfuneko ukuyigubungela nge-polyethylene okanye wenze isakhelo seplastiki. Ungasifaka isixhobo kwi-hook. Ukuba ngaphezulu kwe-2 cm yentambo engenanto ihlala ekuphumeni kumngxunya, gubungela icandelo elingaphezulu ngetape yokukhusela. Indlela yokwenza i-antenna elula ngaphandle kweetoti iboniswe kule vidiyo: https://www.youtube.com/watch?v=kt8u3U-Hp8g

“Ilophu”

Indawo esebenzayo yintambo yeTV. Le antenna yenziwe ngolu hlobo:

1. Nciphisa intambo kwi-eriyali engalunganga.
2. Sicoca isiphelo.
3. Silinganisa i-0.4 m, susa i-insulation ngo-20 mm, uzama ukungonakalisi isiphaluka sangaphandle.
4. Indawo engenanto kunye necandelo elihlanjululweyo liqiniswe ngokuqinileyo ngokuhambelana nocingo.

Isiphumo kufuneka sibe isangqa (esincinci ngaphezu kwe-0.15 m ububanzi) ukusuka kwikhebula njengomamkeli. Emva koko, kwiziko elijongene necala lendawo yokudibanisa, linganisa i-40 mm kwaye ususe i-insulation. Ngoku i-eriyali ingasetyenziswa. Ukungalungi kweso sixhobo ingxolo yayo, ekubeni isiphelo sekhebula sivulekile. Kodwa ukusetyenziswa kwexeshana, i-antenna enjalo iya kwenza. Indlela yokwenza i-antenna ye-loop yentambo elula iboniswe kwividiyo engezantsi: https://www.youtube.com/watch?v=XdD3nANJbQY

Kwi-eriyali enjalo, kuyimfuneko ukuba ne-T2 tuner okanye i-TV kufuneka ibe ne-T2 eyakhelwe ngaphakathi.

I-antenna ngaphandle kwebhokisi

Izinto zokuqala zokwenziwa kwesixhobo yibhokisi yekhadibhodi. Sisika iingxande ezi-2 ze-0.25×0.3 m ukusuka kuyo. Kufuneka ulungiselele:

• Intambo yeTV eneplagi;
• iibholiti, amantongomane (2 iipcs.);
• screwdriver, incakuba;
• ucingo (ngokukhethekileyo ubhedu);
• iphepha lokutya okanye i-foil;
• iglu (umfundisi ufanelekile).

Sinqumla izikwere ezi-2 kwiphepha lokutya (i-perimeter kufuneka ibe njengeekhadibhodi ezingenanto). Zincamathelise ngokuqinileyo kwikhadibhodi engenanto. Sisusa yonke iglue.

Xa usebenzisa i-foil kwikhadibhodi, gwema izithuba kunye neeprotrusions, ngaphandle koko ukwamkela kuya kuba mbi.

Izikwere ezenziweyo ziya kuba yinxalenye yokufumana i-eriyali. Ngoku sidibanisa ikhebula. Nge-blade senza imingxuma yeebholithi – kwiikona zezikwere (amacala akufuphi). Emva koko sidonsa i-contour yangaphakathi kwenye yemingxuma, kunye ne-contour yangaphandle (i-metal casing) kwenye. Siqinisa abafowunelwa ngeebholiti. Sifumana ukwamkelwa okuzinzile ngokudibanisa ikhebula kwiTV. Sihambisa izikwere ngelixa sigcina ukuhambelana kwamacala akufutshane. Emva kokufumana umgama ofunekayo, sidibanisa izikwere kwisakhelo. Bukela ividiyo ebonisa inyathelo ngenyathelo indlela yokwenza i-eriyali: https://youtu.be/gwqKRAePtZw

Sebenzisa isixhobo kuphela njenge -antenna yangaphakathi , njengoko i-foil ayimelani kakuhle nendawo yangaphandle.

I-Z-antenna – i-antenna ye-decimeter ye-digital TV ye-DVB-T2

Esi sixhobo sasekhaya sikwabizwa ngokuba yi “Square”, “People’s Zigzag”, “Rhombus”. Umfanekiso ongezantsi ubonisa inguqulelo eyenziwe lula ye-zigzag yakudala. Ukwandisa uvakalelo, ixhotywe nge-capacitive inserts (1, 2) kunye ne-reflector A. Ukuba inqanaba lomqondiso liyamkeleka, oku akufuneki. Ukwenza i-antenna ngezandla zakho, uya kufuna iibhubhu ezenziwe ngobhedu, i-aluminium, ubhedu okanye imicu ye-0.1-0.15 m. Ukwenziwa kokufakwa kwe-capacitive, i-foil, i-tin okanye i-mesh mesh ifanelekile. Emva kokufakwa, kufuneka benze i-contour soldering.

Ukufakwa kwekhebula kufuneka kuqhutywe ngaphandle kokugoba okubukhali kwaye ngaphakathi kwendawo yokufaka icala.

Inguqulo yeklasikhi ye-antenna ye-Z ibonakala ngokusebenza kwi-1-5 okanye i-6-12 iziteshi. Ukuze wenze oku, kufuneka ugcine stock up:

• ii-slats zomthi;
• ucingo lwe-enameled yobhedu 0.6-1.2 mm;
• izilahlwa zefiberglass (ifoyile), imilinganiselo yeendlela ezihambelanayo 1-5 / 6-12:
  • A = 340/95 cm;
  • B, C = 170/45 cm;
  • b = 10/2.8 cm;
  • H = 30/10 cm.

E – le ngongoma ibonakaliswe ngu-zero amandla – i-braid kufuneka ithengiswe kwi-plate ye-metalized ukuxhasa. Iiparamitha zokubonisa (nakwamanye amajelo ahambelanayo 1-5/6-12):

• A \u003d 62 / 17.5 cm;
• B = 30/13 cm;
• D = 320/90 cm.

Omnye umzobo kunye neengcaciso ezongezelelweyo eziza kunceda ekuhlanganiseni i-antenna zichazwe ngezantsi:

Zenzele i-eriyali esebenzayo yedijithali:

https://youtu.be/l1PuJLS7BlM

i-eriyali esibhozo

Ithathwa njengenye yezona zixhobo ziqhele ukusetyenziswa ekhaya ukufumana iTV yedijithali. Ukwanalo nelinye igama – i-antenna yaseKharchenkookanye i-biquad. Sikwere esime okwedayimani kabini. Esi sixhobo sinokusetyenziswa ngempumelelo kwiimeko ezahlukeneyo, ngaphandle kwezakhiwo ezixinene kakhulu, njengoko ziphazamisa ukwamkelwa kwezibonakaliso ezibonakalisiweyo. Xa uyila “ezisibhozo” kuyimfuneko ukwenza izibalo ezichanekileyo, ngokuqwalasela ubude be-wavelength. Onke amacala esikwere kunye nesiqingatha sobude becandelo lamaza kufuneka ahambelane. Ngenxa yoko, i-perimeter iya kulingana nobude be-wave ngokwayo. Ngokomzekelo, kwi-DTV kummandla we-metropolitan iya kuba yi-0.6 m, ngokulandelanayo, icala elinye li-0.15 m. Ukwenza i-eriyali enjalo, kufuneka ubeke ubhedu (2-3 mm) okanye i-aluminium (5-6) mm) ucingo. Ngokombono woyilo, kuya kufuneka ukuvelisa izikwere ezimbini. Kuyimfuneko ukunqumla i-2 cm ukusuka kwiiphelo zocingo kwaye uzibophe omnye komnye ukuze

Qinisekisa ukuba uhlukanise iziphelo eziqiniweyo zezibini zocingo komnye nomnye, ngaphandle koko i-antenna iya kukhupha isignali kuphela.

Kwisakhelo, i-beam elula idla ngokusetyenziswa. Ukuba zonke izenzo zenziwe ngokuchanekileyo, ummkeli uqiniswe ngokukhawuleza, kuba akuyimfuneko ukujonga ukusebenza. Ikhebula lithengiswa ngokuthe ngqo phakathi, ekudibaneni kocingo luphela kwelinye lamanqaku. Bukela ividiyo malunga nendlela yokwenza i-antenna ye-biquadratic ngezandla zakho: https://www.youtube.com/watch?v=3o0ZBUcL2f0

Izinto ezintathu okanye ezine-element channel wave

Uhlobo lweklasikhi “lwe-wave” lwe-antenna yezinto ezintathu luphawulwa kubukho bamacandelo alandelayo:

• umlawuli, onobude obuncinane kwaye bujoliswe kwinqaba yeTV;
• isidlidlizi soxande;
• isibonisi.

Isixhobo sokufumana – ukuya kuthi ga kwi-6 dB. I-eriyali iyakwazi ukucholachola isignali ebonakalisiweyo ye-DVB-T2 kwiziko likamabonakude malunga nomgama oziikhilomitha ezi-5 okanye ngokubona ngqo ukuya kuthi ga kwiikhilomitha ezingama-30. Ukunganiki inzuzo eninzi, isixhobo esinjalo asifanelekanga ukufumana ixesha elide lokufumana iimpawu ezibonisiweyo. Ukwandisa inzuzo, kufuneka uxhobise isakhiwo ngezinto ezilishumi okanye ngaphezulu. Kunzima kakhulu ukwenza i-eriyali enjalo ngokwakho. Kungcono ukuba nezinto ezintathu okanye ezine. I-algorithm yezenzo imi ngolu hlobo lulandelayo:

1. Kuyimfuneko ukugcina kwi-wire copper okanye ityhubhu ukusuka kwi-0.2 ukuya kwi-0.5 cm ububanzi. Sithengisa isibonisi, umlawuli kunye ne-vibrator kwisikhokelo sesixhobo.
2. Isakhiwo sifakwe kwipali ye-dielectric esecaleni kwekhebula. I-antenna ilungelelaniswa kunye necandelo lentambo ye-antenna – i-U-elbow, kunye nokumelana kwamaza angama-75 ohms. Ubude bayo buphindaphindwa yinto yokunciphisa ekhoyo kwi-brand yentambo esetyenzisiweyo.
3. I-antenna vibrator ithengiswa kumacala omabini kunye ne-core cores ye-U-elbow. Ezi zilandelayo zixhunywe ngendlela efanayo kwizikrini zekhebula eliphumayo, kwaye ingundoqo yayo ephakathi ixhunywe kwi-vibrator ye-antenna.

Ukongezwa komlawuli omnye kuya kunceda ukwandisa inzuzo ngobuninzi be-2 dB, eya kunika i-antenna yezinto ezine kwi-output kunye nokwandisa indawo yokwamkela ezinzile ngeekhilomitha eziliqela.

Inkqubo yokwenziwa kwe-antenna yezinto ezintathu “itshaneli yamaza” iboniswe kule vidiyo: https://www.youtube.com/watch?v=aLY0_7brvbo

Kabini (kathathu) isikwere

Ukuzenzela le eriyali kuyafana nokubala ngesixhobo se-biquad. Uphawu loyilo lulungiselelo lwezikwere eziliqela ezifanayo enye emva kwenye. Umahluko omkhulu kwi-antenna ye-G8 kukungabikho kokufumana isignali ezinzileyo evela kwi-TV ephindaphindayo, esuswa kumgama omkhulu. Injongo yesikweri esiphindwe kabini (kathathu) kukufumana imiqondiso kwindawo yangasemva ephezulu yemitha. Rhoqo inqaba kamabonwakude kwizakhiwo ezixinene kakhulu, nangona ikufutshane, kusenokubakho ezinye iinqaba ezifumana amaza ohlukeneyo atyhutyha i-decimeter wave. Esi sixhobo sasekhaya siyakwazi ukufumana amaza obude obuthile ngaphandle kweengxaki, kwaye idizayini ye-multilevel yesixhobo isebenza njenge-amplifier. Izikwere zifakwe ngokulula kwi-bar. Ukunyusa isixhobo ngokuthe nkqo,

Xhuma izikwere komnye nomnye kungekhona kwindawo esebenzayo, kodwa kuphela ngoncedo lweeseli zamafutha eziphumayo. Ukuba oku kungasebenzi, veza ikhebula ngakumbi kwaye uyithengise kwiikona ezisezantsi zezikwere, uze uyigxininise kwibar.

Emva kokugqiba ukuhlanganisana kwezikwere ezininzi, zilungise okwethutyana kwaye, ngokutshintsha imigama phakathi kwazo, tyhila ukwamkelwa komqondiso ofanelekileyo, uze uzilungise ngokuqinileyo. Uyenza njani i-eriyali kwii-biquads ezininzi ukonyusa inzuzo ibonisiwe kule vidiyo: https://youtu.be/6mCVeQgPqvE

I-Antenna DVB T2 “Butterfly” (“Moth”)

Ngokwesakhiwo, i-eriyali enjalo ibonakaliswe zii-eriyali ezibekwe ngokuthe nkqo. Ngandlela-thile, izixhobo ezinjalo zifana nezixhobo ze-pin yefektri ye-TV yedijithali eyenziwe ePoland, kodwa ziyahluka ngokuba zisebenzisa isakhelo endaweni yoluhlu lwezigaba. Ukwenza “ibhabhathane” ngezandla zakho, kufuneka ugcine isitokhwe:

• i-drill kunye nezikrufu;
• irula kunye neprotractor;
• abasiki bengcingo;
• ucingo (6 mm) olwenziwe nge-aluminiyam 3 m ubude;
• iibholiti ezinamantongomane (ama-16 ama-pcs.) Okanye intsimbi yokuthambisa;
• intonga yomthi.

Njengomthetho, ii-antenna zeTV zedijithali ezenziwe ngePoland zenzelwe ukufakwa kwangaphandle, oku kuthetha ukuba olu yilo luya kufuneka lufakwe ngaphandle. Ukumelana nemimoya enamandla, kungcono ukuba ungasebenzisi ucingo lwe-copper (3 mm) kwii-antenna ezide, kodwa i-aluminiyam eninzi.

Iinkqubo zeTV zeDijithali zisebenza kunye namajelo eTV angama-21 (i-frequency 314 MHz, ubude be-0.63 m). Oku kuhambelana nemitha ephindaphindayo ephezulu ye-RTRS. Ubude obufunekayo bommandla osebenzayo ngu-0.16 m, kuzo zonke “i-antennae” – 2.56 m. Ngoko ke, ucingo lweemitha ezintathu luya kukwanela.

Intonga isetyenziswe njengesakhelo, ubude bayo kufuneka bube ubuncinane be-0.6 m. Kwisakhelo, kuyimfuneko ukwenza iimpawu ze “antennae”. Oku kwenziwa ngolu hlobo:

1. Siphawula amanqaku ama-4 ngokulinganayo (0.2 m) umgama.
2. Sizoba imigca ukusuka kumanqaku, kufuneka alale ngokuhambelanayo kunye ne-perpendicular kwisakhelo.
3. Silinganisa ii-angles ezikufutshane ze-30 degrees (2 ukuya kwesobunxele kunye no-2 ukuya kwesokudla) ukusuka kwimigca echanekileyo kwaye ubeke amanqaku.
4. Sizoba imigca kwi-angle ukuya kumanqaku atyunjiweyo ukusuka kumbindi. Le migca iya kusebenza njengesalathisi sokufakela “i-eriyali”.

Ukuthathela ingqalelo isiqingatha sobude becandelo lomnqamlezo wamaza we-0.15 m, siya kuhlalutya iinketho ezimbini zokwenziwa ngokuzimeleyo kwe-eriyali enjalo.

Ukwenza usebenzisa i-soldering iron

Kule meko, ukwakhiwa kwesakhiwo kuya kuthatha ixesha elincinci kakhulu. Iimveliso zetsimbi zigxininiswe ngokuhambelana kwintonga yokhuni. Kule nto, iziqwenga ezi-4 zetsimbi zisetyenzisiweyo (ziye zadibaniswa emva koko) okanye ucingo. Ukubona i-markup ye-TE, kuyimfuneko ukuba isakhelo sokhuni sihlale sivulekile. Iindawo zokubambelela kwi-antennal ziya kusebenza njengezona ngongoma ziphambili kwi-markup, kwaye imigca efakwe kwi-angle iya kusebenza njengendawo yabo. Sithatha ucingo, sinqumle amacandelo angama-16 (0.15 m nganye) kunye neentambo zocingo kunye ne-solder i-antennae eyenziwe kubo, ihlanganiswe kwiinqununu ezi-4, kuzo zonke iingongoma ezibonisiweyo.

Kuyinto enqwenelekayo ukuba onke amaqela ezinto ahlanganiswe nge-tape yokukhusela.

Ukubholisha

Kulo mfanekiso, akukho zongezo zetsimbi ezifunekayo kwisakhiwo sokhuni – ngokufanelekileyo, isixhobo siya kuba silula. Intonga ikhethwe ngezi pharamitha zilandelayo: ububanzi – 4 cm, ubukhulu – ukusuka kwi-2 cm. Okokuqala, “imigodi” yee-antennae ilungiselelwe nge-drill. Zenziwa kwicala lentonga kwi-engile ngaphakathi ecaleni komgca kwi-markup. Emva koko, imingxuma igrunjwa ngapha nangapha kunye ne-tangent yemingxuma. Isakhelo senziwe. Sinqumle iziqwenga ze-0.17 m ukusuka kwintambo (kunye nomda), sigxininise i-antennae elungiselelwe emigodini ngo-2 cm, uze uzilungise ngokuqinileyo ngamantongomane kunye neebholiti. Sifaka i-antennae ngocingo oluncinci, sidibanise omnye nomnye.

Ukwenza i-eriyali ngale ndlela kuthatha ixesha elingakumbi, kodwa imveliso yomelele ngakumbi kunoyilo oluthengiswayo.

Indlela yokwenza i-antenna yebhabhathane iboniswe kule vidiyo: https://www.youtube.com/watch?v=zGpHdvDyt6s

I-Antenna N. Turkina yokufumana umabonwakude wedijithali

Isixhobo siqukethe iindandatho ezi-6 zocingo lwetsimbi, ezisebenza njenge-vibrators ezisebenzayo kunye ne-passive elements kwaye zilungiswe kwi-dielectric guide. Le eriyali inomsebenzi ongcono wokwamkela kunesikwere esiphindwe kathathu, ngoko ke ihlala ifakelwa ulwamkelo olude lweempawu ze-DVB-T2. I-antenna ye-N. Turkin i-band emxinwa, ngoko ke izicwangciso ezichanekileyo ziya kufuneka ngexesha lofakelo lwayo. Kufuneka ifakwe kwingingqi apho kukho i-multiplex enye kuphela (ukuba kukho ezimbini, ngoko kufuneka zibe kwiitshaneli ezisondeleyo). Xa zisasazwa kwinani elikhulu leendlela, ukwamkelwa kuya kuba kumgangatho ophantsi. Isixhobo sinezi ndawo zilandelayo:

• intonga ye-dielectric apho ukufakwa kuqhutyelwa khona;
• abalawuli i-D1÷D3 ene-reflector R – izakhi zokwenziwa;
• V1, V2 – vibrators;
• amakhonkco e-ferrite (beka ikhebula kufuphi noqhagamshelo kwi-vibrators) – isixhobo esihambelanayo.

Ukudityaniswa kwee-vibrators ezisebenzayo kusekelwe kwisikwere saseSwitzerland: ukudibanisa okunqamlekileyo kwamakhonkco kunye nokucutha okuphantsi ukusuka ngaphantsi.

Ukufakela uya kufuna:

• misela uluhlu lwamaza e-DVB-T2;
• yenza izibalo ezichanekileyo zemilinganiselo yesixhobo;
• yenza iinxalenye, i-solder isiphaluka sombane.

Idatha yokuqala yefrikhwensi kunye namanani etshaneli yokubala inokufumaneka kwiinkonzo zabaqhubi bakamabonakude be-DVB-T2. Siza kuqwalasela umabonakude wedijithali kwitshaneli ye-40, i-frequency ye-626 MHz. Umgama (L) phakathi kwezinto – 29, 72, 96, 60, 96 mm (iyonke – 353 mm). I-circumferences yi-470, 465, 460, 484, 489, 537 mm.
Emva kokuthatha isigqibo malunga neeparamitha, masiqalise ukusebenza:

1. Sikhetha ibha yokhuni (ubude bayo kufuneka bube ngaphezu kwe-353 mm) intonga yokukhusela, ucingo lobhedu (ngokukhethekileyo 2.5 sq. Mm. Kwaye 4 m ubude).
2. Siphawula imingxuma apho iindandatho ziya kufakwa khona, kwaye ziqhube.
3. Senza iivibrators ezisebenzayo kunye nezinto ezenziwayo. Siyinqumle isiseko sobhedu kunye nomjikelezo wendandatho nganye. Sigoba onke amacandelo ngamakhonkco. Kwii-vibrators ezisebenzayo, iziphelo zeendandatho zenziwe nge-gap, ngoko sandisa ubude bamacandelo ngo-8 cm, siguqe nge-angle echanekileyo ukuya kwicala. Sithengisa ngokunqamlezayo ukuya ekuqaleni kokulandelayo.
4. Senza ii-cascade ze-passive elements zibe mfutshane, emva koko sizixhome kwintonga ye-dialectical. Sithengisa iziphelo zeringi.
5. Sifaka abalawuli kwi-traverse. Sidlula i-jumper eyenziwe ngobhedu oluncinci, tyhala i-vibrator ring kumacala omabini. Sifaka i-jumper kwindawo ekhonkxiweyo kumacala omabini kwaye siyithengise.
6. Ukufakela iivibrators.
7. Faka isibonisi.
8. Sidibanisa intambo.
9. Sijonga umgangatho wokwamkelwa.

Phambi kokuba uqalise ukwenza i-eriyali ye-TV yedijithali, kufuneka wazi ukuba yeyiphi eya kwamkela ngcono ifomathi ye-DVB-T2. Emva kokuphonononga iintlobo ezininzi zee-eriyali zasekhaya, unokukhetha eyona ndlela ilungileyo kwimeko yakho.