TeeVee over Fibre
in [Design]
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From: Copacetic on 12 Apr 2010 21:07 On Mon, 12 Apr 2010 22:32:23 +0000 (UTC), David Lesher <wb8foz(a)panix.com> wrote: >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 have an Acer Aspire Revo "nettop" computer that was $200. It is running "XBMC" (X Box Media Server). That runs under windows or Linux, and is what most folks are using for media these days, not MythTV. You should do it as a net stream as that is where things are heading. Even Satellite access is moving toward streaming digital data or files over a network hook than tuning individual "TV channels". Watch for satellite to make a comeback in the form of a network provider, not a "TV channel" programming provider. There are bi-directional systems already in place, no need for phone like the old Hughes system was. > 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?
From: Mark on 12 Apr 2010 21:33 On Apr 12, 4:16 pm, David Lesher <wb8...(a)panix.com> 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.... > >snip > > I welcome enlightenment. > -- http://www.atci.com/ortel_fiber_optics.php Mark
From: David Lesher on 13 Apr 2010 00:13 >> 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 that leave me with my isolation concern. >> 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 :-) $1200 and up... >But if the guy has a 80,000 gallon indoor pool it'll all be chump change. If he spends all his money on this stuff; there will be no pool.. -- A host is a host from coast to coast.................wb8foz(a)nrk.com & no one will talk to a host that's close........[v].(301) 56-LINUX Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433
From: David Lesher on 13 Apr 2010 00:17 Copacetic <Copacetic(a)iseverythingalright.org> writes: >On Mon, 12 Apr 2010 22:32:23 +0000 (UTC), David Lesher <wb8foz(a)panix.com> >wrote: >>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 have an Acer Aspire Revo "nettop" computer that was $200. It is >running "XBMC" (X Box Media Server). That runs under windows or Linux, >and is what most folks are using for media these days, not MythTV. Still a reach for teenage daughters.... > You should do it as a net stream as that is where things are heading. >Even Satellite access is moving toward streaming digital data or files >over a network hook than tuning individual "TV channels". But a Silicon Dust HDHome tuner will bring the DRM/decoding issue into play. > Watch for satellite to make a comeback in the form of a network >provider, not a "TV channel" programming provider. There are >bi-directional systems already in place, no need for phone like the old >Hughes system was. At present, that's what he can get for net access. But no one likes such; just tolerates it.... -- A host is a host from coast to coast.................wb8foz(a)nrk.com & no one will talk to a host that's close........[v].(301) 56-LINUX Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433
From: Paul Keinanen on 13 Apr 2010 01:38
On Mon, 12 Apr 2010 14:42:17 -0700, Joerg <invalid(a)invalid.invalid> wrote: >Paul Keinanen wrote: >> On Mon, 12 Apr 2010 22:55:41 +0200, Sjouke Burry >> <burrynulnulfour(a)ppllaanneett.nnll> wrote: >> >>>> 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? >> >>> There is no advantage in fiber for a direct connection this short. >> >> The first thing I would worry about is the lightning protection at >> such distances. >> >> For a single microwave head for a single polarization generates >> signals in the 0-2000 MHz range, which would require some intermediate >> amplifiers, trying to run two polarizations and multiple satellites >> through a coaxial cable, would require amplifiers every few meters. >> > >Really from 0 MHz? That would be an inconvenience, else you can place >baluns to isolate. Not exactly 0 MHz, since any signal appearing at the image frequency would also get through any front end filtering. Even without any significant signal sources at the image frequency, the first preamp noise falling on the image frequency will also be mixed down to the intermediate frequency, increasing the noise figure. On the other hand, at least in Europe, the head end unit output is typically from 900-2100 MHz, to allow terrestrial antenna signals below that at standard VHF/UHF channels to be transported in the same cable. For a dedicated system, the lower frequency limit could be considerably lower. > > >> Using WDM, there is no problem of handling multiple orbital positions >> and two polarizations on a single mode fiber. >> > >While FO to coax converters are ubiquitous the converters from coax to >FO are probably expensive. Cable TV companies have used for decades high linearity transmitters and receivers amplitude modulating the laser with the whole cable-TV band, originally containing dozens of analog signals and later up to 256QAM digital signals. No doubt these are expensive. On the other hand, down converted satellite signals were originally constant amplitude FM signals, later on BPSK or QPSK and just recently with DVB-S2 up to 32APSK. The linearity requirement is far less. |