Possible Line Fault

I am assisting an elderly person at a distance.

The fault is showing as ADSL synch. cuts out at regular intervals.

The SNRM is set at 15dB to increase stability, this remains constant.

The tel. line has been checked by an OR Tech as ok.

No NTE5, 3 extensions connected and working.

All filters have been replaced.

All the 'phones are functioning correctly.

ISP tests are showing a "Rectified loop"

Any idea on what to check next, or how to progress this?

Thanks.

Edited by Brunel (Wed 29-May-13 12:03:41)

Rectified loop suggests a possible wiring issue with the extensions

Time to either remove the wiring back to just one socket or get Openreach to fit an NTE5 and see if that improves the situation.

Regularising the NTE5 is £25+VAT, but they will charge a lot more if the person wants the extensions reconnecting.

Thanks for the info.

In reply to a post by MrSaffron:

Rectified loop suggests a possible wiring issue with the extensions

Not necessarily the only cause and, quite honestly, unlikely.

A 'rectified loop' is more likely to be the result of poor external joint(s) in the D-side pair which is (are) also showing HR tendencies.

ISP tests are showing a "Rectified loop"

that's a copper loop test showing a fault.

The ISP should reject the Openreach clear, or the end user if they reported a voice fault.

Two different results from the ISP.

1. line test which has detected a possible router fault.

2. Fail - A Rectified Loop fault has been detected close to or within the end user's premises.

This is after a third spare router has been connected.

I am totally confused.

A 'rectified loop' is more likely to be the result of poor external joint(s) in the D-side pair which is (are) also showing HR tendencies.

I'll agree to differ.

Rectified loop, ALWAYS rule out internal wiring and/or equipment 1st.

Can you provide me with some information as to what I should look for

Removing or replacing the phones is no problem.

There is also an alarm system, the type provided by Social Services to assist a disabled person in an emergency, this has to be permanently connected.

Any thing to look for re. the wiring?

You need to find the first socket in the run, follow the external feed to find out where this is, if struggling, can you post some pictures on here ?

In reply to a post by burakkucat:

In reply to a post by MrSaffron:

Rectified loop suggests a possible wiring issue with the extensions

Not necessarily the only cause and, quite honestly, unlikely.

A 'rectified loop' is more likely to be the result of poor external joint(s) in the D-side pair which is (are) also showing HR tendencies.

HR? I doubt it. HRs are continuity faults. Rectified loops are low insulation faults. If you have a rectified loop and an HR, it would be crackles all over the place and a very poorly place to be. .

Rectified loop is more likely to be in the property than in the external network. This is because it is a low insulation fault, low a-b or b-a and low insulation in the external network is likely to show low insulation to battery more prevalently.

But it's a fault and it's a fault that can be masked by the router or can be a result of the router. So it is worth considering getting the provider to test with the router unplugged.

The Openreach tech's expensive, couple of grand, JDSU tester is incapable of reversing polarity when testing for polarized loop faults.

Which is amazing considering that rectified loop faults are as old as the telephone itself and detection depends on reversing polarity to detect and that a cheap, obsolete 40 year old GPO tester SA9083 for twenty quid on ebay can.

Edited by deleted (Wed 29-May-13 21:51:47)

As has been said you need to strip the internal wiring back to a single incoming test socket.

It might even be the alarm wiring thats the issue, it is iether pay Openreach to come out and do this checking, or supply info on the wiring schematic and pictures so people can help remotely

In reply to a post by Zarjaz:

Rectified loop, ALWAYS rule out internal wiring and/or equipment 1st.

This is good advice.

I would always bet on rectified loops being indoors and I would win the bet 9 out of 10 times.

Edited by deleted (Wed 29-May-13 22:16:32)

just get the engineer out. There's a fault, the wiring isn't up to current standards, it needs fixing.

JDSU tester is incapable of reversing polarity when testing for polarized loop faults.

So if you suspect this fault, you reverse the leads and test again, also worth noting that it will show, very well, low insulation, disparity between leg balance, etc, etc.

that a cheap, obsolete 40 year old GPO tester SA9083 for twenty quid on ebay can.

'Walk softly, carry both.'

On the down side, try as I might, I can not get the 9083 to test ADSL/VDSL/SDSL ...........

Thanks to all.

I do have various items of test equipment, including insulation testers and a SA 9083 at my disposal.

I feel confident that I will be able to fault find and effect a repair in what should be a
relatively simple circuit.

Just to add to my confusion, The ISP has completed further tests.

Fail - A possible fault has been detected with the end user's modem.

We have detected a modem on the line, however we were unable to synchronise with the device.

This is now the second modem/router that has shown this alleged fault, both appear to be functioning correctly.

repeated the line test and this is now showing as clear.

The "rectified loop fault" is now not showing.

No changes have been made to either the line or the equipment connected.

Edited by Brunel (Fri 31-May-13 12:38:54)