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mmds chorus on dvb t tv and diablo cam
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yammagamm
Member
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7. October 2008 @ 12:05 |
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hi guys. is it possable to use my built in dvb tuner on tv which has a ci slot that i can put my diablo cam into. and is there any bin files for chorus mmds for the diablo.. or any1 know anything about trying it this way..
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mgb17
Senior Member
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7. October 2008 @ 12:54 |
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First precondition is that the channel scan is able to find the channels.
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yammagamm
Member
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7. October 2008 @ 13:08 |
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yea. i know ill have to put up mmds ariel and down converter first instead of a standard digital ariel..i think i saw chorus on list in txt file of a diablo bin file i have..
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mgb17
Senior Member
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7. October 2008 @ 13:21 |
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Normally the scan procedure for a integrated dvb-t tuner at a tv scans only the UHF range 470 to 860 mhz.
A normal ch*rus aerial deliver the channels in the range 234 to 386 mhz.
That doesn't match.
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yammagamm
Member
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8. October 2008 @ 13:13 |
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thanks mgb17. thats the info i was looking for. as it doesnt say in my lcd manual the dvb-t tuner range..and since we dont have freeview transmitting around here i wasnt sure the different frequencies..
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mgb17
Senior Member
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8. October 2008 @ 13:44 |
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You could use an mmds downconverter from satandcable or a other dealer. Such a downconverter is using the range 662MHz-848MHz but you have to do the installation by yourself.
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yammagamm
Member
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9. October 2008 @ 14:21 |
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just wondering could i use my digiweb metro aerial. ie my isp aerial as that is a powered aerial and presume it has a downconverter. any1 know what frequencies the digiweb metro aerial work.. or could i use my satellite dish and lnb ? as the lnb is a powered downconverter is it not and since i have a motorised 90cm dish..
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mgb17
Senior Member
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10. October 2008 @ 10:22 |
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The things are simply different. You need a mmds downconverter, a power supply for the downconverter and a matching aerial.
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yammagamm
Member
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11. October 2008 @ 17:18 |
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ok so just found out metro digiweb on 10.5 ghz about re rx and tx freq and chorus mmds around 2.5ghz up top and 235mhz to 375mhz on box after downconverter ..was just up on roof and i have a aerial looks like a mmds with a downverter attached to back of it.well box attached to aerial with cable coming from dipole to it and then another cable out of it.and its labelled horizon type b.., i connected a 12volt supply to cable going upto the aerial but no luck using the dvb-t tuner in tv which was from 475mhz to 850mhz so im wondering if i get a tx bow would equiptment on roof do.. any1 have the old horizon type b aerial ??working
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mgb17
Senior Member
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11. October 2008 @ 18:15 |
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Maybe the power supply is too weak. The power inserter has to deliver up to 200ma.
Its also a good idea to check the analogue channels via the tuner of a tv.
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yammagamm
Member
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12. October 2008 @ 11:56 |
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hi mgb17 . power supply 700mA. will i be able to pick up the analogue channels on mmds ?ie rte1 rte2 and so on.also is this tread right as in frequences ? before and after downconverter ?http://forums.afterdawn.com/thread_view.cfm/562886
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yammagamm
Member
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12. October 2008 @ 19:19 |
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just reading loads more treads here and reading some downconverters might have 2 output freq ranges.? think there were 2 f connector points on the horizon type b which i believe is a down converter. also any way to measure the frequency ? i have a fluke 83 meter that can read frequencies tried reading it on the rf cable but could get no readings never used it for reading this before but did read 50hz from a socket so know the meter is working,, would the second f connector on the horizon type b be another output freq range ?
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mgb17
Senior Member
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12. October 2008 @ 20:48 |
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Scan for the 5 available analogue channels via the tuner of your TV and check the frequencies at the TV.
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yammagamm
Member
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13. October 2008 @ 17:15 |
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could not pick up any of the 5 analogue channels on the mmds aerial,which is pointing straight at woodcock hill and i have a very good line of sight sitting here typing i can see the safety beacons on the masts. so not sure if the 12 volt power inserter that i borrowed from my digiweb metro setup is enough or could that have some kind of filter built into it to block out other frequencies?????,it only sends the 12 volts out 1 side upstream, is this the norm for inserters ??? i have a few psu`s lying around somewhere and might make my own power inserter using a old sky magic eye enclosure and around 18 volt psu.think ill put new rg6 cable up as well as dont know how good or old cable run is to aerial once i get a roof ladder sorted to rule that out as well.all this even before i start on the diablo..
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mgb17
Senior Member
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13. October 2008 @ 17:26 |
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Maybe the polarization of the aerial is wrong or the analogue tuner at your TV is only willing to scan the UHF range.
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yammagamm
Member
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17. October 2008 @ 12:10 |
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hi... tried manual scan on another crt tv using the aerial and downconverter for the analogue channels on the 3bands still no luck , tried another power supply on 18 volts with 1000mA as well as the 12volt 200 mA SUPPLY....anyone ever come across these horizon type b downconverters ?... o yea i bypassed the downconverter and getting good picture on uhf maybe the downconverter is just shot..??and i guessing the type b on the downconverter is for group b aerial ? but any1 come across these horizon typeb downconverters ?
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carlow
Newbie
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17. October 2008 @ 17:35 |
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Originally posted by yammagamm:
ok so just found out metro digiweb on 10.5 ghz about re rx and tx freq and chorus mmds around 2.5ghz up top and 235mhz to 375mhz on box after downconverter ..was just up on roof and i have a aerial looks like a mmds with a downverter attached to back of it.well box attached to aerial with cable coming from dipole to it and then another cable out of it.and its labelled horizon type b.., i connected a 12volt supply to cable going upto the aerial but no luck using the dvb-t tuner in tv which was from 475mhz to 850mhz so im wondering if i get a tx bow would equiptment on roof do.. any1 have the old horizon type b aerial ??working
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carlow
Newbie
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17. October 2008 @ 17:47 |
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any two part down converter and di pole will not work for digital mmds transmissions,if you require an areil it can be sorted for you,but are u sure woodcock hill is transmitting?woodcock hill where??wicklow or clare or wexford?chorus recently turned off a few of there transmitters throughout the country because the areas had a stronger signal comming from a near by ntl transmitter,or beacause the customers could still get a signal with larger poles being monted.the mmds service is due to be decommisioned when the dtt service goes online during the next few years and upc will offer a topup tv style service.
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mgb17
Senior Member
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17. October 2008 @ 18:00 |
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Why should a dipol with extra downconverter not working. The signal doesn't care about if the downconverter is builtin into the feedarm or attached behind the dipol with a short cable run.
The problem is to find out if the downconverter is still in working order. Installations with extra downconverters attached to the back of the aerial are stone old.
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yammagamm
Member
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28. October 2008 @ 18:56 |
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ok im back. got a new downconverter/feedhorn type getting 100% signal but feck all quality using old mesh with new downconverter strapped to old dipol arm, moving it up down arm max im getting is 10% about, had it placed exact distance old feedhorn was but not working.are feedhorns matched to mesh aerials ? like dishes ? and is the distance of feedhorn critical ?. i say the mesh aerial is slightly larger then new ones as its 59 x59 cm so would this have effect on focal point of signal in relation to position of feedhorn ?im picking up T4 on analogue tuner but pointing it slightly away from masts on woodcockhill..
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carlow
Newbie
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29. October 2008 @ 19:14 |
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all two part set ups are different lenghts but very little difference will be accieved by changing it,all combined downconverters and diepoles are aset lenght.using a two part set up will not give you a good signal always,its like using an ariel put up in the sixty's to get freeview.the thing was made before digital transmittions were even thought of,its just not conpattable,chorus use two types of transmittions a & b,214 & 222 do you know if your using the right type???????????????????????
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mgb17
Senior Member
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30. October 2008 @ 02:01 |
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Originally posted by carlow:
all two part set ups are different lenghts but very little difference will be accieved by changing it,all combined downconverters and diepoles are aset lenght.using a two part set up will not give you a good signal always,its like using an ariel put up in the sixty's to get freeview.the thing was made before digital transmittions were even thought of,its just not conpattable,chorus use two types of transmittions a & b,214 & 222 do you know if your using the right type???????????????????????
Are you kidding. A UHF aerial made in the sixty's is still able to receive freeview. The aerial doesn't care about the content.
Beside that a downconverter which is not matching the frequency scheme give the the channels in a other frequency range. Thats it.
This message has been edited since posting. Last time this message was edited on 30. October 2008 @ 03:25
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mgb17
Senior Member
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30. October 2008 @ 02:04 |
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Originally posted by yammagamm:
ok im back. got a new downconverter/feedhorn type getting 100% signal but feck all quality using old mesh with new downconverter strapped to old dipol arm, moving it up down arm max im getting is 10% about, had it placed exact distance old feedhorn was but not working.are feedhorns matched to mesh aerials ? like dishes ? and is the distance of feedhorn critical ?. i say the mesh aerial is slightly larger then new ones as its 59 x59 cm so would this have effect on focal point of signal in relation to position of feedhorn ?im picking up T4 on analogue tuner but pointing it slightly away from masts on woodcockhill..
Are you sure the polarization is right. The head of the feedarm have to be verticaly or horizontally oriented. Check the mmds aerials in the neighbourhood.
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carlow
Newbie
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30. October 2008 @ 18:55 |
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it doesn't pick up in a different frequency range,its not capeable of doing that.theres an 8meg shift between channels it wont work,i've done it,trust me it doesn't work otherwise there would be only one type.and saying a 1960's ariel is as good as recieving freeview,it a crock,you might aswell be telling people to use a wire coat hanger as an areil.it wont work reliably,or consistantly and it wont do everything its supposed to do.these things are made for a reason
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yammagamm
Member
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31. October 2008 @ 16:57 |
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carlow.. i dont know what you are on about ? downconverter has built in feedhorn what some ppl call dipol now. i had downconverter just strapped to old galvanised box section dipol arm with old feedhorn removed as i had said in previous post.it should work with the horizon mesh aerial as they are basically same as new ch@r@s ones. the downconverter is a UHF 1 ie input 2500-2700mhz L.O. 1838mhz so that is start of 662mhz +4 to get centre of band so 666mhz. DVB-T tuner starts at 474 to 850mhz in 8mhz steps so ch45 is 666mhz. it is picking up T4 /ET and TV3 not the best but there but only when pointing away from masts. woodcock hill is vertical.. ch@r@s.. i got rid of them as my isp through mmds years ago as had major problems with signal and harmonics effects as temp dropped it actually worked better with mmds aerial pointing away from mast as well as i had 2 good line of sight/signal.. mmds/ch@r@s and me dont match..lol.. and all this before i start with the diablo cam,
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