Non-simultaneous Multi-room

oisinaodh

Hi,

I am considering getting satellite TV and am wondering if it is possible to do non-simultaneous multi-room in an ad-hoc fashion. The house currently has cable points in a number of different rooms but I would not want to go to the expense of having a decoder in every room so what I am wondering is it possible to have the satellite signal fed to the currently installed coax segments via a splitter(s) and then to move the decoder from room to room as desired. Basically what I am asking is how portable is the decoder or is their some other technical reason why this wouldn't work ? For example, I currently have a very small portable DVD player so if I'm watching a DVD in one room and someone else wants to use the room I can just carry the player to a different room and continue watching. Presumably the digital satellite feed is just another signal which would be connected to my existing coax segments so I could just carry the decoder from room to room as desired? Or would the splitters cause signal degradation that would affect picture quality?

Thanks,

Usjes

watty

If the cable is good enough quality and all go back to a central "patch point", yes- but without a splitter. You can't have more than one cable connected right through to the LNB on the dish. Splitting & amplifying a satellite signal is more expensive than a basic set box.

You can't use TV splitters.

Satellite cable splitters are for specialist installation with Multiswitch trunk amplfiers.

you'd have to swap a connection at some centralised point the cables go to.

oisinaodh

Hi Watty,

Not sure I understand, are you saying that the input to the decoder (from the satellite dish) does not travel over simple coax ? So I'd have to have the decoder at a central location and then physically plug in the end of a different segment of coax to the decoder output as I went from room to room ??

Usjes

snaps

You would need a multi output lnb (As satellite signal cannot be split), then cables from the multi output dish to all rooms you will want to watch FTA satellite. You could get a receiver with a RF output and use that to feed the other rooms, but you will run into difficulty changing channels unless you use a old skybox with UK epg and a magic type eye. Standard FTA multiroom is not that expensive to setup as there are many cheap FTA receivers about now.

oisinaodh

So if anyone can help, with the minimum possible of unexplained TLAs (what's an LNB???). Note that I am interested in DECODING (ie not FTA) digital TV. The problem could be reformulated as follows:
I decide to get digital (cable or satellite) installed in the kitchen while my parents are away, my mother subsequently decrees we are not having a TV in the kitchen so I take the decoder and move it to another room, there is already coax routed from the kitchen to the second room and a third and a fourth room, my presumption is that I can just pick up the decoder and move to any of the other rooms by attaching the feed from the cable or satellite dish to the existing coax segments ??? If not WHY not, with a minimum of TLAs please if possible. The responses above assert that satellite signals cannot be split, why ?. Once I have split it the decoder will still see a satellite feed coming down a piece of coax, how would it even know that it has been split ?? Granted the signal strength would be lower but so would it be if my house was simply further from the transmission point or depending on weather conditions presumably ?
Ultimately my intention is to move the decoder from room to room as needed, possibly on a daily basis, but in principle I don't see it as being any different than getting digital TV installed in one room in you house an subsequently deciding to move it to another room are the above posts saying that this is effectively not possible or would be a big job? If so then why do most modern residences have TV points in many rooms??

Thanks,

Usjes

emaherx

LNB = Low Noise Block, its the part of the dish where you connect the cable.
cables coming from this cannot be split between receivers as there are 4 operating modes of this device.

You can get quad and octo LNB's with 4 or 8 outputs but you need to run each cable unsplit directly to the LNB. A quad LNB is about 40 euro. ( this is the best setup as it lets you add aditional receivers later if you wish.)

If you only ever use one receiver you may get away with splitting cable but normal Ariel splitters will not do due to High Frequency's involved. (they may work for very short cable runs but again its not a good idea to split at all)

Most modern houses are wired for Multiple TV points by electricians who have no idea about satellite systems using inferior cable. These are usually wired with terrestrial TV in mind.

Best setup for your System is to Set up sky in one room then connect the RF2 out(Thats how its marked on the back of box) to the other rooms using a terrestrial distribution with DC bypass (Most modern distribution amps do this) and use a sky eye (to send remote signals to digi box) in each room to control the sky box. All TV's in the house could then receive sky Using one box (same channel of course).

Alternatively Set up box in one room but use a wireless video sender to send signal to which ever other TV you want to watch. (These also send remote signals back to box to change channels)

watty

oisinaodh wrote: »

Hi Watty,

Not sure I understand, are you saying that the input to the decoder (from the satellite dish) does not travel over simple coax ? So I'd have to have the decoder at a central location and then physically plug in the end of a different segment of coax to the decoder output as I went from room to room ??

Usjes

It uses higher quality coax, but it's coax.
You'd need to either have a multiple output feed on the dish arm, or swap the cable over at a central point if you want to move the receiver box around.

The LNB is the actual 1st part of satellite receiver on the end of arm at the focus of the dish. The living room box connected by coax is actually a 2nd half of the receiver. It feeds power to the LNB on the dish arm and varies tone & voltage sent up to the dish to select one of 4 blocks of channels. Each block is about 4x as much signals as UHF and is at a higher frequency, thus the need for high quality coax to stop signal leaking out or in which would interfere with DECT cordless phones and all three mobile phone bands, and these things would interfere with the satellite converted signals too if the coax was not good enough.

TV channels on UHF go 21 to 69, if you used the SAME scheme (which they don't) the satellite signals would be chs 75 to 275! Not only that but according to signals sent from the decoder box to the LNB (the dodah on end of arm facing into dish) there would be four complete sets of these. In practice a satellite system doesn't use these numbering and a "channel" (transponder) is maybe 8 times bigger than a regular tv channel and have many TV signals and radio "multplexed" into it. This how over 120 radio and over 800 TV can be received at once by the dish.

I hope this clarifies why a TV splitter/amp can't be used and the coax must be "satellite grade".

There ARE ways of splitting a satellite signal, but you usually have a satellite Trunk amplifier and Satellite grade splitters. Ordinary splitters don't pass the power and tone back up the cable, nor cope with the frequencies up to 3x higher. If you do succeed in having the correct equipment to split signal then you can't connect a 2nd receiver at the same time unless the system has FOUR coax feeds and Quad or Quattro feeding a multiswitch.

Satellite distribution is very simple if you use proper coax and don't split the signal.

So EITHER
1) swap a single feed cable to which ever coax is in use at a central point. Stereo sound and best quality RGB video via SCART cable to TV.
OR
2) have a Quad LNB with 4 coax. You can add more receivers later up to four.Stereo sound and best quality RGB video via SCART cable to TV.
OR
3) leave the receiver in one place and feed it's Modulator out via a TV amp to all the cables. YOu can have a remote eye if it's a Sky digibox. Non-Sky receivers may not have a modulator. The picture is poorer and sound mono.
OR
4) Use a video Sender. Slightly better video and stereo sound. Remote control and works on any satellite receiver.
OR
5) A professional Quattro /Quad driven distribution system. 1 to 4 satellite feeds and 16 to 1000 satellite receivers all from one dish. Stereo sound and best quality RGB video via SCART cable to TV.

If you want HD, then 3 & 4 don't work. HD needs option 1, 2 or 5

FTA is free and gives about 10 decent radio and 45 decent TV out over 80 Radio & 200+ TV.
For English Speaking Pay TV (non-FTA needing decryption) only Sky subscription on a Sky Digibox is possible.

Tony

oisinaodh wrote: »

The responses above assert that satellite signals cannot be split, why ?. Once I have split it the decoder will still see a satellite feed coming down a piece of coax, how would it even know that it has been split ??

Because A. It will not receive a viable signal as the splitter would be too lossy and B. It would not be able to send the control voltage to the lnb . As my friend suggests using the cable output from the box is the best way to view in other rooms in your situation.

watty

Some of us are communications engineers and/or have been professionally installing this kind of gear since before Digital TV.

We aren't making up the pitfalls and difficulties of splitting the satellite signal.