what can cause noise on the line

[jfish]

as per my other post on splitting a signal, I would give more back ground on this

On Monday I got a card thru letter box about some issue from my house with signal and someone needed to come and check the line.

The connection was as follows

- cable from outside to box on wall
- signal split 2 ways - one goes to broadband router the other to upstairs to my Edison OS Mini DVB-C box

engineer came over this morning and saw the guy who came in on Monday had put some blocker on the signal from upstairs

Obviously to keep my cable box a secret told the engineer I had nothing connected upstairs

so he took out splitter and joined the one cable to the cable modem router and left

He mentioned noise was being generated on my line which caused issues in the street, so what can cause this noise

dodgy cable
dodgy connections

The splitter that was in the box outside was provided by VM

I called VM up to ask about splitting cable inside, they qupted me 100 quid

hence my other post asking about best cable to use and best splitter to use to split the signal again

Don't want another RPBLOCK card in future so want to make sure anything I add doesn't cause any issues

 

[Napster]

mine is split outside in brown box, to lounge and bedroom, the lounge has a splitter 3 way superhub 3,v6 box, and solo2 with cable tuner attached, bedroom has a solo2 with cable tuner attached been like that for a while never had anything from virgin and hope I don't. I thought noise came from yellow bricks stuff like that, cant see a box causing noise.

 

[jfish]

mine is split outside in brown box, to lounge and bedroom, the lounge has a splitter 3 way superhub 3,v6 box, and solo2 with cable tuner attached, bedroom has a solo2 with cable tuner attached been like that for a while never had anything from virgin and hope I don't. I thought noise came from yellow bricks stuff like that, cant see a box causing noise.

I don't have any signal boosters, he did mention the if the cable to upstairs was not connected to anything can cause interference with the RF signals which then gets into the cable and down the line. You do have a rather complex setup, for me I want to split cable inside so one goes to cable modem router and other to a DVBC box but don't want it to cause any issues.

 

[Napster]

I cant see it causing any problems m8 at all mine is fine.

 

[Spectre]

I don't have any signal boosters, he did mention the if the cable to upstairs was not connected to anything can cause interference with the RF signals which then gets into the cable and down the line. You do have a rather complex setup, for me I want to split cable inside so one goes to cable modem router and other to a DVBC box but don't want it to cause any issues.

A bit of a guess but due to the frequencies involved it might be because the transmission lines (cables) aren't terminated as expected. As he said, it could be because there is no termination (unplugged cable), which might cause reflections back into the network. Or termination of the incorrect type for the network (different types of tuner perhaps).

Reflections of signals on conducting lines - Wikipedia
Mismatch loss - Wikipedia

My background isn't HF networks otherwise I'd probably be able to test tuners with a network analyser or something .

 

[jfish]

A bit of a guess but due to the frequencies involved it might be because the transmission lines aren't terminated as expected. As he said, it could be because there is no termination (unplugged cable), which might cause reflections back into the network. Or termination of the incorrect type for the network (different types of tuner perhaps).

Reflections of signals on conducting lines - Wikipedia
Mismatch loss - Wikipedia

My background isn't HF networks otherwise I'd probably be able to test tuners with a network analyser or something .

 

[jfish]

i did have the Edison box unplugged for a week so this could have caused the issue , for future can I plug something into the loose end to stop interference going down the line

 

[jfish]

to summarise because I unplugged my Edison box and left cable as it was, it causes some noise on the line which VM detected. Had a quick google I need a termination cap to put at end of cable if not connected to anything, I guess if the cable was connected to my Edison then that wouldnt have caused any issues.

 

[Spectre]

to summarise because I unplugged my Edison box and left cable as it was, it causes some noise on the line which VM detected. Had a quick google I need a termination cap to put at end of cable if not connected to anything, I guess if the cable was connected to my Edison then that wouldnt have caused any issues.

You might be able to get away with unscrewing the cable at the splitter end if you need to unplug the box.

 

[jfish]

You might be able to get away with unscrewing the cable at the splitter end if you need to unplug the box.

got no splitters anymore, as the VM engineer who came this morning took it away with him when I said I no longer have anything connected to upstairs where the cable was going to and where it was plugged into the Edison box