Can a single Co-ax line be split for SKY +

pistolpetes11

I was just wondering can you split a single feed coming from your dish to offer SKY + in a room with only one feed ?

I had all the rooms in the house wired with ct-100 all coming back to a point under the stairs , I only realized when I got my SKY HD put into the house that you need two lines feeding into the box.

It was grand in the main bedroom as he came in very neatly from outside in through an air vent and behind the wall and same in the sitting room but that leaves me with the other rooms with only a single feed, Its there a one in two out distro amp that I can use in the rooms where I only have a single feed ?

Under the stairs I have a one in six out so I am hoping it is possible !

jhegarty

Short answer : No

pistolpetes11

Why would that be now ?

Is the one in six out not working on the same principle , its giving six signals out ? would the box not just see to signals coming in and work away ?

watty

The short answer is NO.

The long answer is NO.

The pedantic answer, there is a way...

The long answer: NO
The LNBF or LNB at the dish arm is actually part of the receiver. It does two bands, like the equvilent of LW & MW or SW1 and SW2 on a radio. It also does two polarities. On MW you can have two stations on nearly the same frequency about 90 degrees apart and rotating the Radio will "null" out one or the other.

So the signals arriving at dish are H & V polarity (the LNB can only receive one or the other) and in the bands 10.7 to 11.6GHz and 11.6GHz to 12.6GHz (the LNB can only receive one or the other). This means the LNB has on the IF coax cable in the 950MHz to 2000MHz band at any time only one 1/4 of channels (potentially).

The rest of the receiver is in the Satellite Set box. It powers the LNB via DC on the coax, but the voltage is set at 13V or 18V to select on the LNB internal switches either Vertical or Horizontal polaraised signals (the LNB horn has two small 1/4 wave whip aerials inside it. About 6mm long!). Then if there is a 22kHz AC signal of about 0.5V superimposed on the DC power the LNB's Local Oscillator is switched from 9750MHz to 10600MHz to change the band received.

So if you split the signal then there is 3 out of 4 chance that the satellite boxes are SENDING different signals to the LNB. You could either have wrong channel (no signal) on one or both boxes or even damage the receivers. The misleading thing is that some of the time the two receivers will both work showing correct channels.

Also TV distribution Amps only work up to about 870MHz. The Satellite IF is 950MHz to 2100MHz band.


Pedantic answer: Yes
Obviously if you had an LNB/LNBF with four outlets you could have each of the four possible groups of signals at the same time. Then you could split them. You need later to combine them in a special 4way switch box (usually a Multiswitch) that uses the Set-box LNB signals to select the correct 1 of 4.

A Quad LNB has four outlets, each can be any of the four signals. Indeed SOME multiswitches can set each outlet to be permanently one of the four signals. Normally a rather different LNB/LNBF is used called a Quattro. Each outlet is only one of the four possible sets of channels.

Using a Quattro (or up to 8 Quattros for 8 different satellites) you can feed up to 1000 receivers via amplifiers, splitters and Multiswitches.

I have a multiswitch with 16 +1 in and 16 out. So it can take 4 Quattros (four satellites) and drive up to 16 receivers, only the first LNBF/LNB can be a Quad instead. If I added four sets of Quad splitters, then I could add a 2nd Multiswitch. A cheaper multiswitch may have 4 in (one satellite) and only 8 outlets (to the sat receivers).

Many Multiswitches are available with TV distribution built in. An extra input accepts 5MHz to 870MHz. If it has an amplifier for TV it won't work with Cable broadband. If it is "passive" for TV, many work with Cable Broadband too.

At the outlet you run cable to Satellite Setbox and fit a cheap 850MHz TV/Sat splitter to feed Satellite Receiver and TV or DTT or Cable setbox or Modem.

If using for MMDS, put the MMDS PSU infront of Multiswitch TV in. The passive TV in Multiswitch will work with TV, FM Radio, SW Radio, DAB, MMDS, Cable (Analogue, Digital and Broadband) or Digiweb Metro Coax as long as any PSU for the coax is in front of the Multiswitch input,

kuro_man

No, but there is an alternative: a stacker/destacker - they cost about €120 plus delivery on ebay. They take one line and change the frequency so that is doesn't interfere with the other - combine both down the same cable to a second box which separates them and puts the frequency back to what is should be again.
It may add some noise to the signal but on a digital signal that should be removed by the receiver.
Apparantly, there should be no extentions, wall plates, diplexers etc. between each the stacker and destacker.

I haven't used one so I no first hand experience but would be interested to know if it works ok.

kuro_man

Stacker/destacker - £79 on ebay

pistolpetes11

The stacker /destacker option look like it could solve the problem ! Does any one have any experience of that type of unit ? Cheers Watty for the breakdown on what can/can not be done , its much appreciated

watty

They only work well on short highquality cables. To be avoided.

If the conduit is big enough use the coax to pull in nylon builders cord.

Then use that to pull two coax back in. (one can be the original if not kinked).

gibo_ie

I use a stacker/destacker in my apartment as the builders only pulled one cable in to each apartment. I have two feeds at the riser coming in to the stacker, then across one single cable into the house then the destacker breaks it into two and into the sky box. It woorks great and i have a secobnd cable from the sky box to the bedroom with a magic eye so i can change stations when in bed.
I actually bought two stacker/destackers by mistake so have one for sale if i can dig it out.
PM me if interested, if not ill put it up on adverts next week anyway. €100 (converting from £79..)seems to be fair if you pick up - i'm in Dublin city centre.

Sam Radford

Make sure the cable can handle 3,550 MHz.

bruschi

after doing a quick search, i think this may be a solutionto my problem also.

basically, I have the house wired with a standard tv cable. but obviously the sky plus needs 2 cables. will the destacker option work? dont fancy paying 100 quid or so if its no use. or would it be as handy to connect a cable to the satelite and runot down the wall and just drill back in to give it the secondcable to the box?

Zonda999

If you're able to OP, a bigger LNB(oct0 lnb comes to mind) would be a much cheaper option

Apogee

bruschi wrote: »

after doing a quick search, i think this may be a solutionto my problem also.

basically, I have the house wired with a standard tv cable. but obviously the sky plus needs 2 cables. will the destacker option work? dont fancy paying 100 quid or so if its no use. or would it be as handy to connect a cable to the satelite and runot down the wall and just drill back in to give it the secondcable to the box?

Standard TV cable will be marginal for use with a satellite receiver and probably unworkable with a stacker/destacker. PH100 type cable or equivalent is recommended for satellite and a minimum requirement for stackers.

bruschi

Apogee wrote: »

Standard TV cable will be marginal for use with a satellite receiver and probably unworkable with a stacker/destacker. PH100 type cable or equivalent is recommended for satellite and a minimum requirement for stackers.

the sky plus box works and get get tv fine witht he cable, just dont have the recording facility thats all. not exactly sure of the make up of the cable itself.