Lines appearing on my tv

johnnyb6

Hi I hope I am on the correct forum. I have 4 wires coming from my sky dish. I have a sky plus HD box. My signal goes to attic where its boosted and then fed around house. However the last few weeks lines are appearing on all tv in house from time to time. When I disconnect cable going from back of box to attic, lines disappear. Would anyone have any idea whats happening.


Thanking you

STB.

You are using an RF modulator to feed the other TV's ?

Try changing the channel on the RF modulator.

There is a device/other RF frequency affecting the RF Feed.

johnnyb6

STB. wrote: »

You are using an RF modulator to feed the other TV's ?

Try changing the channel on the RF modulator.

There is a device/other RF frequency affecting the RF Feed.

Sorry STB but I have no idea what you mean. Where is this RF modulator located. Are you talking at back of Sky box

STB.

johnnyb6 wrote: »

Sorry STB but I have no idea what you mean. Where is this RF modulator located. Are you talking at back of Sky box

Ah a Sky box....

The Sky box has an RF modulator built into the box. An RF modulator is a system of sending the signal of the Sky box to other TV's over analogue.

That is going to a box in the attic. That box in the attic is a distribution box.

The other TV's in the house are tuned into a channel to view the same channel being played on the sky box right ? Probably channel 68 on the other room TV's. You can change the channel that is sent around the house on the Sky box. Try 60. Then retune one of the receiving TV's to channel 60.

johnnyb6

STB. wrote: »

Ah a Sky box....

The Sky box has an RF modulator built into the box. An RF modulator is a system of sending the signal of the Sky box to other TV's over analogue.

That is going to a box in the attic. That box in the attic is a distribution box.

The other TV's in the house are tuned into a channel to view the same channel being played on the sky box right ? Probably channel 68 on the other room TV's. You can change the channel that is sent around the house on the Sky box. Try 60. Then retune one of the receiving TV's to channel 60.

How do I change the channel on sky box

STB.

johnnyb6 wrote: »

How do I change the channel on sky box

Hang I have re-read your original post.

You have 4 cables coming in from the satellite dish. Where are they going ?

Two into the Sky HD+ box ? and the other 2 ?

Are you able to watch different satellite channels in the other rooms to the one with the Sky HD box ?

Thurston?

johnnyb6 wrote: »

... I have a sky plus HD box. My signal goes to attic where its boosted and then fed around house. However the last few weeks lines are appearing on all tv in house from time to time. When I disconnect cable going from back of box to attic, lines disappear.

You must be disconnecting the 'aerial in' cable if the lines are disappearing but the picture isn't?

'Lines' as opposed to 'snow' could be from an overloaded aerial amplifier. Do you know what your terrestrial aerial system consists of?

johnnyb6

STB. wrote: »

Hang I have re-read your original post.

You have 4 cables coming in from the satellite dish. Where are they going ?

Two into the Sky HD+ box ? and the other 2 ?

Are you able to watch different satellite channels in the other rooms to the one with the Sky HD box ?

I think I have 3 cables going into Sky box. I also had an old sky box in attic and I think 1 cable feeding this for the free to air channels, I now have a ARIVA 250 box up there. Hope this helps you

johnnyb6

Thurston? wrote: »

You must be disconnecting the 'aerial in' cable if the lines are disappearing but the picture isn't?

'Lines' as opposed to 'snow' could be from an overloaded aerial amplifier. Do you know what your terrestrial aerial system consists of?

I am sorry but I don't know what you mean. I am getting my saorviev channels true TV 3 ariel

STB.

johnnyb6 wrote: »

I think I have 3 cables going into Sky box. I also had an old sky box in attic and I think 1 cable feeding this for the free to air channels, I now have a ARIVA 250 box up there. Hope this helps you

Okay. 2 of the cables going into the Sky box+ are satellite cables. What is the other one connected to ? Is it TV/RF out ? Is this the one that you disconnected that stopped the lines appearing on your TV that you are watching the Sky + box on ?

Thurston?

johnnyb6 wrote: »

I am sorry but I don't know what you mean. I am getting my saorviev channels true TV 3 ariel

Which channels are the 'lines' appearing on, & what is the label on the socket on the Sky box for the cable you unplug?

I'm assuming the 'lines' are on the analogue output from the Sky HD box.

STB.

Thurston? wrote: »

Which channels are the 'lines' appearing on, & what is the label on the socket on the Sky box for the cable you unplug?

I'm assuming the 'lines' are on the analogue output from the Sky HD box.

Thats the question. Its probably an aerial connected to the RF modulator out or a TV aerial in the RF passthrough..

johnnyb6

STB. wrote: »

Thats the question. Its probably an aerial connected to the RF modulator out or a TV aerial in the RF passthrough..

the cable which I disconnect is going into ariel in

STB.

johnnyb6 wrote: »

the cable which I disconnect is going into ariel in

Ok. RF (radio frequency) from your aerial is overloading the box.

On your aerial down cable coming into the attic their is possibly a box connected to it called a masthead amplifier.

They look sometimes like this.



They normally have a variable gain. You need to turn it down with a screwdriver.


I am assuming that your RF modulator is not on the same frequency as your Saorview Channel frequency!

johnnyb6

STB. wrote: »

Ok. RF (radio frequency) from your aerial is overloading the box.

On your aerial coming into the attic their is possibly a box connected to it called a masthead amplifier. They normally have a variable gain. You need to turn it down.

I will head to attic tomorrow evening and get back to you if this is ok. Is it usual to have to turn this down as I haven't ever needed to before and the lines only come on tv from time to time. Should they not be constant if this was the case

Thurston?

johnnyb6 wrote: »

the cable which I disconnect is going into ariel in

That's all it could have been, assuming the lines are appearing on the Sky box output, viewed on TVs fed from the Sky box RF modulator.

Interference from a Saorview (or Freeview) channel on the same frequency as the Sky box RF output would be random 'snow', rather than lines or other patterning, which is why I wondered about something overloaded (or malfunctioning) in an earlier post.

johnnyb6

STB. wrote: »

Ok. RF (radio frequency) from your aerial is overloading the box.

On your aerial down cable coming into the attic their is possibly a box connected to it called a masthead amplifier.

They look sometimes like this.



They normally have a variable gain. You need to turn it down with a screwdriver.


I am assuming that your RF modulator is not on the same frequency as your Saorview Channel frequency!

Now that I see your pic I think there is def more than 1 of these in the attic

STB.

johnnyb6 wrote: »

I will head to attic tomorrow evening and get back to you if this is ok. Is it usual to have to turn this down as I haven't ever needed to before and the lines only come on tv from time to time. Should they not be constant if this was the case

Its not an exact science more process of elimination. That starts with checking the integrity of the cables and joiners. Checking outside factors such as DECT phones.... making sure that if you are using an RF modulator that it is not within a few channels in frequency as the broadcast Saorview Channels. Those channels frequency vary throughout the country.

For Example in the South East the Saorview Channels are on Channels 23 and 26, so using an RF modulator which combines Saorview and the RF output from a Sky box on a very near Channel would cause interference.

Yes comeback, there are plenty that will answer your question.

STB.

johnnyb6 wrote: »

Now that I see your pic I think there is def more than 1 of these in the attic

I hope not!

You only need one of those unless you have more than one aerial. The output of that needs to go into the Sky box first if for combining both the RF modulator and the Saorview signal before going to any distribution box(es).

You need to follow the cables in the attic.

It could be that you have stuff junctioned wrongly in the attic.

johnnyb6

STB. wrote: »

I hope not!

You only need one of those unless you have more than one aerial. The output of that needs to go into the Sky box first if for combining both the RF modulator and the Saorview signal before going to any distribution box(es).

You need to follow the cables in the attic.

It could be that you have stuff junctioned wrongly in the attic.

Hi just checked the attic and I was wrong. What I have is 2 ,4way splitter units which look like what you showed. I also have a power unit and a white box with UHF and VHF on it. this is also run by power. I also have splitter box for Sky eye to each room

Thurston?

How many TVs you have in the house, & do they all have Saorview available, as well as the Sky box output?

Was all this stuff professionally installed?

Maybe post some pics of the items you describe in the previous post, showing how they connect together. (Or describe how they interconnect.) There's probably a simpler, cleaner way of setting it up.

johnnyb6

Thurston? wrote: »

How many TVs you have in the house, & do they all have Saorview available, as well as the Sky box output?

Was all this stuff professionally installed?

Maybe post some pics of the items you describe in the previous post, showing how they connect together. (Or describe how they interconnect.) There's probably a simpler, cleaner way of setting it up.

I have 6 tv sockets and 5 tv and they all have saorview . All connections were done by professional tv guy. I changed from a sky plus box to a sky plus HD box few months ago and tv guy came and sorted it out as box had to be recorded true sky as it was few years old but never used. The tv guy changed some fittings for no reason I know as he replaced them with same ones. I think he was justifying his price. If one of those connections weren't done right , would this cause some interference from time to time on all tvs

Thurston?

I don't think the problem is caused by the wrong cable being connected to the wrong socket or something, if that's what you mean.

If the aerial is in the attic, it will be prone to pick up any electrical interference from within the house, & display it as 'lines' on the analogue picture or, the interference could be generated within the aerial system itself, possibly by an overloaded or dodgy amplifier, as already mentioned. Did you notice is Saorview affected when the 'lines' are in evidence?

What are the 2 x 4-way splitters BTW? Are they actually satellite/terrestrial diplexers?