TV or Aerial Cable Interference?

My broadband has been installed for over 10 years on an extension line with no issues. Recently my connection keeps "dropping" sometimes for minutes, sometimes for hours. I moved my router to the Master BT Box and used the test socket, which restored the service to normal. However, using the Master box but the consumer socket, I have the same problem with the service as explained before even after unplugging any other equipment from the line and extensions. I have replaced the filters also. When I plug in a telephone handset (I usually only use this line for broadband) I notice there is quite a lot of noise (crackle) on the line, but not when plugged into the test socket, so I'm guessing this is the problem. The only recent change I can think of is that I had an aerial cable installed in August which runs alongside and across the extension socket cable for about 15 cm. Could this be causing the problem?

If there are extensions off the faceplate, then look at removing the ring wire

http://www.thinkbroadband.com/faq/sections/radsl.htm...

This generally reduces noise pickup.

In reply to a post by MrSaffron:

If there are extensions off the faceplate, then look at removing the ring wire

http://www.thinkbroadband.com/faq/sections/radsl.htm...

This generally reduces noise pickup.

It's quite likely that if the extension wiring was ok before. then whoever fitted the aerial cable has disturbed it, have a look for any loose joints.

ring wire removal at the master faceplate is always a good idea.

Thanks for your help. I removed the bell wire from all extensions and have checked the wiring for loose connections but still have the same problem. Any more suggestions?

15cm of aerial cable would not normally cause major problems especially as it is shielded but a television does generate a lot of RFI (noise) and some could leak onto the aerial lead. A badly designed or faulty television could push a lot of noise onto the lead some of which could be radiated and picked up on the phone wires. It would need to be very high level to cause problems.

Fully power off the television and disconnect the aerial connection - see if the problem remains.

If it disappears then TV at fault. If it remains then the only way it could be connected to the aerial is if there is a local amateur radio enthusiast and your aerial is picking up his transmissions - which are then re-radiated along the lead - again unlikely but it can happen.

Have you tried powering off everything, and I mean everything, including fridge, freezer, central heating, gas fire &c and then bring back a single circuit to power the modem/hub/router and PC? If it still fails you have ruled out all your domestic electrics.

Wouldn't your test require a second stage? To wit, reconnect the aerial to the TV, leaving the TV powered off, (not on standby). Just so there is a complete circuit for the aerial. (Possible rot, but I'm just asking).

Remember, this is HF/VHF so the co-ax itself is presenting an impedance to any signal. Connecting the TV might or might not change the results. RFI detection is a black art at times and it never follows the rules.!

One of my colleagues managed to get a Orange GSM base station to significantly reduce power (after an initial shutdown) because of interference it was causing.

"May or may not" . That's exactly why I agree with you the first step is to completely disconnect, but then follow up with a "dead" connection. On reflection, followed by a TV in standby, and finally TV in use. I wonder if set-top boxes are involved. Any one of the connections between the bits of kit could have been disturbed. Including a short aerial pass-through cable.

Edited by RobertoS (Sun 13-Jan-13 14:15:01)

Assuming you mean the removable Consumer Socket which has to be taken off to access the Test Socket on the Master Box (NTE5); and that the problem returns when you put that back on, suggests that the problem lies in that specific part - and not onwards in your domestic/consumer wiring.

You plug your phone in to the Test Socket directly - no noise.

Replace the Consumer Socket, plug the phone in to that Consumer Socket (and nothing else) - NOISE?

Possibly that Consumer Socket part needs replacing.

Edited by deleted (Sun 13-Jan-13 15:06:21)

The "Consumer Socket" is normally called a faceplate, and the extension wires are attached to the terminals on the back of it.

The whole point of the design is to remove extension wiring effects from the test socket, so as to be able to test the line itself.

Replacing the faceplate therefore reconnects the extension wiring, which is the probable source of the noise.

There may be a fault on the faceplate, as you suggest, but these are very rare. (Filtered faceplates often have the filter failing, that I accept). Trouble somewhere along the wiring is far more likely given the sequence of events.

Thanks everyone for your help.

So ..... I removed the extension wires from the back of the face plate on the main BT box so all extensions were isolated from the main box, replaced the face plate and still had the same problem with noise when plugged in to the face plate, no noise when plugged in to the test socket. So this suggests it is not the extension wiring that is causing the problem. So it must be either interference or the the face plate socket itself. So the next question is, if this was being caused by interference, wouldn't it effect the test socket connection as well?

That sounds like eckiedoo was right. .

You can get NTE5As, (that's what the faceplate is), at many places. You also (already) need an IDC/Krone tool for a couple of quid or less to reconnect those wires properly.

Maplin is one for faceplates, online possibly broadbandbuyer. Or get a filtered faceplate for neatness, plus an IDC/Krone from ADSL Nation, Solwise or Clarity.

Edit - It could just be the actual socket of the faceplate has got muck in, or its own plug going into the test socket is dirty or corroded. Is there any damp?

Edited by RobertoS (Sun 13-Jan-13 17:31:24)

My money goes on a dry joint in the removable faceplate acting to pick up the interference rather than a total component failure

Replacement faceplates are easy enough to source

Thanks, I have no direct experience of the NTE5, so was working from first principles.

Agreed about isolating the house wiring, I can achieve that in a slightly different way.

I have the older LT2(?), with all the Consumer side coming off the one plug going in to that. The plug leads on to a small distribution point for the various extensions around the house.

It was preceded by the very early version, with about a 1 cm square hole in the middle, a contact on each side, feeding in to various PLAN 4(?) sockets around the house. These were similar to the Jacks used on PBX's to connect the Operator's Headset.

That Master Socket was part of the original installation done in 1967 whilst the house was being built, the PLAN 4 extensions being about 10 years later.

About 1986, I had the line checked from the Exchange for early dial-up use for remote access to a main frame, PCW8256 purchased October 1985, modified to PCW8512 in August 1986., when the line was measured at about 23 db, typically 24 db today.

Thanks again to everyone for their help with this.

I have bought a new Master Socket and box from Maplin (Brand is Kauden and comes with a plastic wiring connector tool £13.00).

My existing box has the two banks of 3 connectors labeled 1 - 6 with connections as follows (after removing the bell wire, Orange- White hoops) -

1- Empty
2- Blue - White hoops
3 - Empty
4 - White - Orange Hoops
5 - White - Blue Hoops
6 - Empty

The new face plate has only three connectors, labeled 2,3,5. So you can see that this does not correlate with the above. Logic would suggest connecting wire with White - Orange Hoops (Currently terminal 4) to terminal 3 on the new face plate. Is this correct?

Thanks in advance for your help.

No, not correct, just use 2 & 5

4 is sometimes connected for neatness and if it works without the bell wire fine, if not reconnect Or/Wh to 3.