Thanks for the advice everyone. So there really isn't *any* way of knowing. Out of interest, are noise issues more of a problem in urban or rural areas? I'm thinking that if noise is caused by electrical interference then there will be less noise in rural areas?
Thanks again.
TM
'Noise' (and we're
not talking audible noise here) is prevalent on
all circuits. The further the distance from exchange to premises, the more 'noise' you will receive. It's pure physics.
The 'noise' that you are on about attempting to measure in your opening post, is completely different to the electrical noise you later mention. The type we can measure is commonly paired against the signal strength of the circuit. IE- SNR (Signal-to-Noise Ratio) and is measured in dB (decibels). Dynamic Line Management sytems are in play to lift the signal strength above the 'noise' levels when levels start to rise, usually during the day.
The electrical interference (REIN) is much more of a faulty 'noise' and can severely disable broadband circuits. There is only so much we can do to counter REIN 'noise' and thats only if it's negligible REIN. If it's much more prevalent, then the actual source has to be located and remedied.
As an aside, rural lines can actually be worse affected by REIN noise due to poorly earthed electric fences, especially when the Openreach cables run in parrallel beneath them. But, as well as affecting the broadband side of the circuit, a 'ticking' audible noise can also be heard on the telephone with this type of fault. We get these during hot, dry spells and the earth spike is effectively surrounded by high-resistance earth. A couple of remedies are 1) To inform the farmer , or 2) To relieve oneself on the earth spike. That usually lasts long enough until the farmer sees to it.