@7LM
Thanks again, I've come to terms with my distance/line/attenuation, knowing there's nothing I can practically do about them. Even with the fact that 'my' telegraph pole seems to be worse than others in either direction in the village in delivering sync rates. In the village, we all get above the BT database spec of 512kbps, so I realise there's nothing I can complain of to them. Its the things that I just might be able to affect that niggle me, such as (prior to my experiments), identifying the best modem/router and settings for the conditions - done - making the best wiring scenario in-house - done - minimising/eliminating any interference from within premises - done - eliminating conducted mains interference - done (there was none) - and trying to minimise interference from outside my immediate control, if I can. Practically, I can't really hope to identify interference from neighbour's property and expect them to allow me to dabble with their equipment.
But, as something of a hobby in my retirement, I do offer a computer/broadband/software assistance service to friends/aquaintances/older citizens within our 2 villages, and sometimes the opportunity to fix a problem which affects more than just the 'owner' does crop up. Like the previous chap next door whose problematic power issues affected all his neighbours.
The fact that I'm down to the incoming phone line as the 'bringer' of interference, whatever its origin, is something I can accept as outside my sphere of influence, so the past days of experiments have been a confirmation that I've done all I can to improve my broadband lot.
The 1500kbps profile I aim for is fine for almost all my purposes - I can't say it is a problem - it is way up on the 90-120kbps I got as a newcomer to broadband 3 years ago, before I had the benefit of this forum (and which I still occasionally find at 'clients' premises - eg one chap on 118kbps who is now on 3000). But I'm always trying to squeeze a bit more when I can, and I have got at least 1 more procedural approach to try out - and more may arise!
Cheers,
Jack