Yeah, I know. Sorry, I wasn't clear. I do mean the incoming line, not powerline adapters.

The way to find out turn off the mains at fuse board run DSL kit and device to look at stats from another power source

Noise on the incoming power supply to a house is a long shot guess

Yeah, I just remembered that I did that and the FECs continued. The FECs/re-transmissions sometimes stop when nothing else turns off in the house. Weird.

Visited the property yesterday and generated the HLog, QLN and bitloading graphs from the test socket, see here. The Powerline adapters were not plugged in at that point, so the plots represent 'the best we can get'!

I then put the faceplate back on and repeated the plots, see here. As you can see, apart from the U2 section of the bitloading graph, they plots are very similar. This is as expected, as there are no sockets wired in downstream of the master socket.

We then reinstated the Powerline adapters and I started a big download while connected to the remote Powerline adapter. Even though I have enabled 'VDSL compatibility mode' on these adapters, the effect on the bitloading graph is obvious, see here.

As I said in one of my other posts, this is an old cottage which has been renovated and extended on several occasions. The Openreach cable comes in overhead at the back of the cottage, and the master socket is located at the front of the cottage, although we know this is unlikely to have been the original master socket location. From the test socket plots I think it is clear that the wiring isn't perfect in the first place and the Powerline testing suggests the wiring is too close to the mains electricity cabling.

As this is an issue with the wiring upstream of the master socket, would Openreach entertain the request of running a new cable from the joint outside the house to a new master socket close to this joint, i.e. minimise the cable length in the house? If not, it is just something we might have to do ourselves as the current setup is not fit for purpose .

Last but not least, line stats from mid-day yesterday:
Stats recorded 19 Dec 2018 12:00:21

DSLAM type / SW version: BDCM:0xa48c (164.140) / v0xa48c
Modem/router firmware: AnnexA version - A2pv6F039v.d26a
DSL mode: VDSL2 Profile 17a
Status: Showtime
Uptime: 3 days 16 hours 35 min 3 sec
Resyncs: 1 (since 14 Dec 2018 09:23:18)

Downstream Upstream
Line attenuation (dB): 20.6 0.0
Signal attenuation (dB): Not monitored
Connection speed (kbps): 34999 6209
SNR margin (dB): 8.4 5.4
Power (dBm): 12.6 5.1
Interleave depth: 16 1
INP: 44.00 0
G.INP: Enabled Not enabled
Vectoring status: 5 (VECT_UNCONFIGURED)

RSCorr/RS (%): 0.6518 0.4465
RSUnCorr/RS (%): 0.0000 0.0000
ES/hour: 0 9.90

That dip in your Hlog about tone 1600 should not be present, especially when connected to the test socket.

That's a job for OpenReach, as you've ruled out an internal wiring.

They charge to move the incoming feed, but if the issue is buried in the wall between the cable entering the property and the master socket they would be responsible for replacing this section.

They don't go ripping walls up, any defective cable is left in the wall and replaced.

Edited by j0hn83 (Thu 20-Dec-18 11:24:06)

Thanks for the feedback. How would we get this fault reported to Openreach? I suspect the ISP will simply say that the line is operating 'within tolerances'... FYI, the end user currently has the phone and broadband contract with John Lewis (Plusnet).

Call them up, ask for line tests.
Hopefully it fails.

Have you run a quiet line test with a corded telephone? Dial 17070 with the powerlines off.

The line appears to have bridge tap, it should fail the ISP tests and they should appoint an engineer from these tests failing.

If you are there when any engineer arrives, mention the Hlog (even better show them the graph).

I�d not bother mentioning the Hlog, it will mean sod all to most Openreach staff.

In reply to a post by Zarjaz:

I�d not bother mentioning the Hlog, it will mean sod all to most Openreach staff.

Perhaps those who install fibre may not.

Any decent engineer who does regular pair quality tests on copper circuits should know what an Hlog is.

If it's mentioned then it won't be left as is.

In reply to a post by j0hn83:

Have you run a quiet line test with a corded telephone? Dial 17070 with the powerlines off.

Yes, we did that initially and the line sounds fine (unfortunately I guess )