Distribution Sky & RTE

ajc45

I am from Northern Ireland and was helping a friend get sky distributed in every room. Very basic house, small bungalow, 4 rooms...

Four tvs going to splitter box in attic picking up uk freeview in all rooms. Now one tv is capable of clearing the five irish channels. I must get the make and model number of this tv to see exactly what it has that the other tvs don't but he tells me its saorview compatible...

Now when I distribute the sky tv through analogue, all tvs get it and uk freeview remains but the tv capable of receiving the irish channels looses them but keeps uk freeview...

The Cush

Which 5 Irish channels does he receive, there are more than 5 on two different frequencies?

What output channel does the Sky box use, maybe its conflicting with one of the Saorview frequencies?

Thurston?

ajc45 wrote: »

when I distribute the sky tv through analogue, all tvs get it and uk freeview remains but the tv capable of receiving the irish channels looses them but keeps uk freeview...

Interference from the Sky box? Post the UHF channel the Sky box outputs on, as well as both UHF channels Saorview is received on. (There are 2 Saorview multiplexes (muxes): RTE1 is on mux 2, RTE2 is on mux 1, so it should be obvious if one of them is missing.)

ajc45

Its on channel 68, its actually through an rf modulator as the sky box doesn't have rf...

I only looked briefly at the tv, rte1 was on but he's getting rte2, in the north we refer to the five irish as rte 1&2, tv3, tg4 and 3e

Thurston?

If the channels only disappear when you switch on the modulator, then it must be interference from the modulator, even if its channel is set well away from Saorview. I would try different output channels, as this might shift the interference somewhere else.

ajc45

The tv is a hitachi 24hxj15u. Ive googled this tv to see if it is unique in any way in regards to receiving irish channels. I did comb through an argos help thread where irish channels were mentioned but it was quickly replied to as no it can't.

Four tvs in the bungalow and only this tv is picking up irish and it is by far the lowest spec tv. Surely the tv must having something built in to allow it to receive irish...

As stated above, as soon as sky distribution is in place the irish drops off this one tv....

The Cush

ajc45 wrote: »

Its on channel 68, its actually through an rf modulator as the sky box doesn't have rf...

You may already know this, RF functionality can be restored to a Sky box, without an RF out, using an IO Link - http://www.tvlink.co.uk/iolink.html

Kevin McCloud

The Cush wrote: »

You may already know this, RF functionality can be restored to a Sky box, without an RF out, using an IO Link - http://www.tvlink.co.uk/iolink.html

Worth saying also only powerful for one eye, if using a distribution amplifier the amp would need a dc supply.

The Cush

ajc45 wrote: »

Four tvs in the bungalow and only this tv is picking up irish and it is by far the lowest spec tv. Surely the tv must having something built in to allow it to receive irish...

As stated above, as soon as sky distribution is in place the irish drops off this one tv....

Does the Hitachi have a FreeviewHD tuner for BBC, UTV HD etc.? FreeviewHD and Saorview use MPEG-4 video compression (Freeview SD channels use MPEG-2).

As Thurston says above it could be a modulator problem.

How good is the Saorview signal at the TV, strength/quality reading?

ajc45

Ok I have sussed the problem but still need a little help fixing it. All tvs in the house are actually getting irish channels....the masthead amp is making this happen, if i take the roof aerial from the fringe electronics p1215 psu and just put it into the UHF port of the splitter box I get no rte....the roof aerial coax must go through the p1215 psu...

So my guess is the amp and the rf modulator are not compatible....generally speaking are rf modulators ok to use with masthead amps...

It does still work with the modulator but as stated above I lose the rte channels when wired up....

Thurston?

The masthead amp won't work without power, obviously.

Explain properly how the system is configured, the order of components from the aerial down.

For this kind of system, I would expect: aerial > masthead amp. > (diplexer if 2 aerials) > masthead PSU > Sky box/modulator aerial-in > cable to main TV, cable to distribution amp > cables to other TVs.

ajc45

Its not my house, and I haven't ventured onto the roof....only one aerial cable in coming through the roof and into the masthead amp psu then into the uhf port of 4 way splitter box...

I have ran a cable from uhf port of splitter box to mercury rf modulator and extended the roof aerial coax from the masthead amp psu to the aerial in port of rf modulator...

Everything is working, sky and freeview but RTE channels drop off....

I have done this before, never had any trouble, so its definitely the fact that a masthead amp is in place...

Generally should rf modulators work fine with masthead amp psu's...

Thurston?

From where the cable enters the house on down is enough info., no need to go on the roof.

ajc45 wrote: »

I have ran a cable from uhf port of splitter box to mercury rf modulator and extended the roof aerial coax from the masthead amp psu to the aerial in port of rf modulator...

What is the combined length of these cables?

ajc45 wrote: »

I have done this before, never had any trouble, so its definitely the fact that a masthead amp is in place...

You can't really say that, as you've no way of testing if Saorview + modulator output works without the amp. in place.

Did you try different modulator channels & see if it makes any difference?

ajc45

This is just a small bungalow, there isn't even any tv points in the house, just coax cable coming through the ceiling hidden in trunking, cable i would say max 10m...

I have changed channel number on my mercury modulator from 68 to 60 then to 50 but all the same.

I always use a mercury rf modulator or a triax tri link. i am going to order a triax tri link to see if there is any difference...

Thurston?

So you've introduced an extra 10 metres of cable between the masthead PSU & the splitter? I don't know if the Mercury modulator has any gain on the aerial loopthrough. (Tri-Link does.) Did you try the system with this cable in place, but without the modulator on the cable?

Hard to really comment further, without knowing what the Saorview signal is like to begin with: could be poor enough that any added attenuation or RF noise is enough to render it unusable.

ajc45

Ok I will try the triax tri link and will also try the aerial cable extended straight down to the tv instead of going through the modulator...

If worst comes to the worse, have i got an alternative to get sky/freeview with rte working together....

Im thinking a second splitter box and extra coax feeds going to each room, that puts two coax cables needing to go into each tv. Will a 2 way splitter/diplexer be needed, is this doable?

Thurston?

Shouldn't be a problem getting it working the 'standard' way I outlined in post #11, which I'm assuming is the way you're doing it now, & have done in previous cases. A few metres extra cable or the noise from the modulator shouldn't wipe out Saorview reception, unless the Saorview signal is very poor to begin with, or the modulator is particularly poor in this respect.

Refinements in the form of filters can be added, to keep the modulator noise out of the aerial signals, & anything the aerial picks up on the modulator channel off that, but shouldn't be necessary for the system to at least function.