Thank you all, I will be arranging to borrow my old MacBook Pro in the next few days because I know that does have Ethernet facilities. I wonder why modern laptops such as the HP Envy 15 and even the new MacBooks I notice have done away with Ethernet sockets in favour of USB C? I guess to facilitate thinner and thinner cases.
I have now tested my line via an old MacBook Pro with the Ethernet cable connected to a micro-filter and into the BT test socket on my NTE5a master socket. Not much difference it appears to me but about 2 more Mbps on the TP-Link VR 2800 sync speed. Hope the images are large enough to read.
Child Okeford Cabinet 1 (Huawei)
Your connection is still terrible compared to your expected range from dslchecker results your attainable is also very low and suggests a problem with your connection/line and I would suggest you phone 150 and get engineer visit
Thank you all and especially @imjolly and @pippincp for your patience and suggestions. An engineers visit would seem to be the best way to go although I will not be amused if I am told that my line meets the 36Mbps Stayfast guarantee criterion (it is close) and that I will be charged for the visit!
I need to wait about 3 weeks for my recent Pfizer vaccination to "mature" before having a home visit from an engineer just to be safe.
Not near enough target SNR and shows a line problem. With a good line on a Huawei cab your noise margin should be about 3.0dB with G.INP or 6.0dB without.
Some feedback on my original post as thanks to the experts here who gave up their time to help me.
After a delay with Covid jabs etc I phoned 150 and reported my slow line speed as advised.
A Cube engineer came, changed my NTE5a to a 5C but declined to touch the C1973 underground dropwire - house wiring connection (6 joints in 6 inches). He escalated the problem to OR. but nothing happened so I made another appointment for an OR. engineer.
He was brilliant, he neatly terminated the connection with 2 jelly crimps and spent in total, 2.5 days (yes, really), following my underground line back to the cabinet 200m away. He found an underground junction box not shown on OR. plans and reduced the V. high cross-talk figures.
I have posted the results after the DLM has gradually increased the line speed, a terrific improvement! Downloads via oopla @ 42+ Mbps are common now, not 26-27 Mbps as previously. My line is close to the 50/10 profile stated by the engineer.
Thank you all again.
You can provide feedback to Openreach, its always appreciated.
https://www.openreach.com/thank-an-engineer-form