TeeVee over Fibre
in [Design]
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From: Jan Panteltje on 12 Apr 2010 18:44 On a sunny day (Mon, 12 Apr 2010 22:32:23 +0000 (UTC)) it happened David Lesher <wb8foz(a)panix.com> wrote in <hq071m$bta$1(a)reader1.panix.com>: , but is the Satellite TV system feed >really ATSC, QAM, or something else? The LNB is simply a down mixer. So the transmission system is not changed, just the frequency.
From: Joerg on 12 Apr 2010 18:47 David Lesher wrote: > Copacetic <Copacetic(a)iseverythingalright.org> writes: > > > >> You can make it fiber if you convert everything to a network stream at >> the feed end and back to video/data/all else on the receive side. >> Essentially placing a server at the signal source, and use a media server >> in the home to pull streams from it. > >> Use 10GbE or 100GbE over fiber. > >> There will be no inexpensive method to pipe the streams you want, the >> way you want. I just hope you know that. > > No, I don't know that. Lots of video is run over fiber in many > forms. [Belden just bought one company that does that at > sporting events...] When I last looked at broadband video over > fiber 15+ years ago, it was doable but pricy. Now, I don't know > that's even still true. > > True, if we turn it unto TCP/IP at the head end; it's > straightforward, but that will need MythTV or similar at each > set. I'm aware of an ASTV tuner with internal web server > that does that encoding, but is the Satellite TV system feed > really ATSC, QAM, or something else? > Doesn't look like it: http://en.wikipedia.org/wiki/ATSC_%28standards%29 Quote "Very few teleports outside the US support the ATSC satellite transmission standard, but teleport support for the standard is improving. The ATSC satellite transmission system is not used for direct-broadcast satellite systems; in North America these have long used either DVB-S (in standard or modified form) or a proprietary system such as DSS or DigiCipher 2." -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Martin Riddle on 12 Apr 2010 19:22 "Joerg" <invalid(a)invalid.invalid> wrote in message news:82hhijFabkU1(a)mid.individual.net... > David Lesher wrote: >> Oh learned s.c.d; the source spring of all knowledege; I humbly >> request a very small smidgen of your wisdom..... >> >> TV over fibre -- No, not the stuph Verizontal sells.... >> >> I have a friend & client building a log cabin in the woods. >> (To set the scale, the [indoor] pool is 80Kgallons.) >> >> It's 1200 ft to where the solar array and satellite dishes will >> be. My question is: who if anyone makes the electronics needed >> to convert to glass for both video down and any data back up? >> >> I have as little to do with TV, much less satellite TV, as >> possible; I assume you can use one dish on multiple receivers, >> which implies the feed from the dish is at some IF but is >> broadband of many megahertz. >> >> (The alternative is the channel selection takes place at the >> dish; which would one channel at a time. I understand that's how >> SBC's U-verse is set up; the settopbox actually sends channel >> commands back to the 29-B coffin..) >> >> I welcome enlightenment. > > > Why not use Airflex or Ecoflex coax if you are worried about > attenuation, then equalize at the amp? Should be cheaper than fiber > and less hassle. For the data link I can't imagine that needing more > than 1200bd so CAT5 should work. But you may have to splice that since > ordinary spools only contain 1000ft. > > -- It looks like 200' is the max for unamplified LNB cable runs. Even with low loss cable and amps mid way, it still may not work well. Then you need to power the amps, etc. But, someone does make LNB-Fiber links <http://www.dawnfiber.com/auto_links/pdf/FSS-95F5T.pdf> He should call them to see if it will work in a consumer application. Cheers
From: Joerg on 12 Apr 2010 20:49 Martin Riddle wrote: > "Joerg" <invalid(a)invalid.invalid> wrote in message > news:82hhijFabkU1(a)mid.individual.net... >> David Lesher wrote: >>> Oh learned s.c.d; the source spring of all knowledege; I humbly >>> request a very small smidgen of your wisdom..... >>> >>> TV over fibre -- No, not the stuph Verizontal sells.... >>> >>> I have a friend & client building a log cabin in the woods. >>> (To set the scale, the [indoor] pool is 80Kgallons.) >>> >>> It's 1200 ft to where the solar array and satellite dishes will >>> be. My question is: who if anyone makes the electronics needed >>> to convert to glass for both video down and any data back up? >>> >>> I have as little to do with TV, much less satellite TV, as >>> possible; I assume you can use one dish on multiple receivers, >>> which implies the feed from the dish is at some IF but is >>> broadband of many megahertz. >>> >>> (The alternative is the channel selection takes place at the >>> dish; which would one channel at a time. I understand that's how >>> SBC's U-verse is set up; the settopbox actually sends channel >>> commands back to the 29-B coffin..) >>> >>> I welcome enlightenment. >> >> Why not use Airflex or Ecoflex coax if you are worried about >> attenuation, then equalize at the amp? Should be cheaper than fiber >> and less hassle. For the data link I can't imagine that needing more >> than 1200bd so CAT5 should work. But you may have to splice that since >> ordinary spools only contain 1000ft. >> >> -- > > It looks like 200' is the max for unamplified LNB cable runs. Even with > low loss cable and amps mid way, it still may not work well. Then you > need to power the amps, etc. IIRC Ecoflex is around 11-12dB per 100m at a GHz, so you'd lose 40-50dB over this run. Doesn't sound so terrible if amplified and equalized correctly. Amps can't be that expensive, for regular UHF I've got several in the basement here to drive coax runs. > But, someone does make LNB-Fiber links > <http://www.dawnfiber.com/auto_links/pdf/FSS-95F5T.pdf> He should call > them to see if it will work in a consumer application. > Sez reasonable pricing, whatever that means :-) But if the guy has a 80,000 gallon indoor pool it'll all be chump change. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Copacetic on 12 Apr 2010 21:01
On Mon, 12 Apr 2010 22:32:23 +0000 (UTC), David Lesher <wb8foz(a)panix.com> wrote: > >No, I don't know that. Lots of video is run over fiber in many >forms. [Belden just bought one company that does that at >sporting events...] And you think those systems are cheap? Jeez. Wake up. That term I gave was 10GbE, not ONE. |