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Technical News & Discussion => IDNet Help => Topic started by: colirv on Jul 27, 2009, 15:55:14

Title: Noise on the line
Post by: colirv on Jul 27, 2009, 15:55:14
Can anyone suggest what might be causing this? Something intermittent, obviously, but I don't think it's anything in the house.



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Title: Re: Noise on the line
Post by: rireed3 on Jul 27, 2009, 16:10:23
Next time you see it, try picking up the phone and dialing 17070 and select quiet line test, or for a quick test just dial one digit.  These silence the line so you can hear if the noise is all-spectrum (like lightning or electric motors) and if it has a mechanical pattern.

Edit: If you hear only a very faint steady hiss, the noise is not in the audible spectrum.  Others can describe how to de-tune a MW radio and see if you can find a source in your house.

Richard
Title: Re: Noise on the line
Post by: Rik on Jul 27, 2009, 16:21:24
What Richard said. If you've got a battery-powered AM radio, tune away from a station in the MW band, so you just have white noise. Then wander along the line of your phone cable listening for the noise to get louder.
Title: Re: Noise on the line
Post by: colirv on Jul 27, 2009, 17:46:00
Thanks both - I shall give all of this a go. And if the noise doesn't reappear, that's a result as well!
Title: Re: Noise on the line
Post by: Sebby on Jul 27, 2009, 19:07:29
It's not particularly bad, Colin, but I agree with the others that there's something causing it and a de-tuned AM radio is the way to go. :)
Title: Re: Noise on the line
Post by: trophymick on Jul 27, 2009, 21:05:46
I tried the detuned radio, (it's a new one for me :thumb:) and it gets very noisy at the junction box where the line comes into the house, it's a very old 'GPO' box. :eek4:  Otherwise it's as quiet as a mouse. :thumb:
Title: Re: Noise on the line
Post by: Rik on Jul 28, 2009, 09:58:45
Is there any mains wiring or equipment nearby, Mick?
Title: Re: Noise on the line
Post by: trophymick on Jul 28, 2009, 12:56:45
Sorry for the late reply Rik, I had to pop out this morning. :thumb:
No there's nothing near it, the wire goes up the side of the door frame and into the GPO box, then the wire (newer) comes in from outside to the box, to join it all together. It's funny the radio is just giving quiet white noise all the was along the hallway and up to the box, as soon as it goes near the box, it gets really loud. :dunno: It's fun checking it though. :thumb:
I had a look in the GPO box and there are only four wires in total connected, (2 joined to 2) but there are other wires coiled up in there doing nothing. :whistle:
Title: Re: Noise on the line
Post by: Rik on Jul 28, 2009, 13:17:12
Standard for a junction box, Mick, the exchange pair joined to the house wiring, the other wires are there in case you ask for a second line.