ukhardy07 - thanks for your reply. I appreciate the cable before the master socket is mine and as the socket is easily accessible (it's not attached to the wall) I just had a look at the cable but have left it connected. The cable from the black box immediately outside the house is white and runs from outside straight to the master. There are no joints between the black box and the master that I know of.

I'm currently on a 40/10 package with Sky. I was on an 80/20 package with BT originally but downgraded as there was no real benefit in actual use.

I'm getting the free upgrade to 80/20 that Sky are rolling out, and seeing as my noise margin has since dropped from 13.1db to 10.1db I wondered if I could do anything to get it back up a bit to maximise the speed I would get once upgraded as the faster speed is now more important than it was previously.

BT cable using these colour codes was normal in the 1970s, Orange and Blue were the A & B wires, normally for internal wiring the Green and Brown would be used for the ring wire and recall, I have to be honest and say twisted pairs wasn't something engineers ever thought about in those days as it was a voice only service.

They are also the same colours for the currents Openreach internal 2 pair

So the cable could be old or newish! 🙂

Well I�d suspect it�s new-ish, as the old cable with those colours was often grey on its exterior.

As someone else posted, I suspect you are barking up the wrong tree, a couple of metres of cable is highly unlikely to be the cause of higher than expected attenuation.

Edited by Zarjaz (Wed 02-Jan-19 13:33:11)

There was a period before the new colour coding came in when the outer sheathing was white, the fact that its stapled rather than clipped probably helps to date the work.

I do think that 19.1 dB attenuation for what appears to be 300ish metres (admittedly as the crow flies) does sounds a lot, even if it was aluminum I wouldn't expect it to be that high.

Strange things happen - as I suspect you know.

Straight line distance from my place to the cab, 50m, actual pair length 181.

" I appreciate the cable before the master socket is mine"

Is there a "not" before 'mine' missing?

Ha, good spot. They should indeed be a "not" in there! I'm really surprised that when at a previous house I trimmed back the cable that the snr increased by 3db, unless it was just coincidence?

In reply to a post by giggsy1977:

Ha, good spot. They should indeed be a "not" in there! I'm really surprised that when at a previous house I trimmed back the cable that the snr increased by 3db, unless it was just coincidence?

SNR varies throughout the day, e.g. in the evening it is often lower. It does not usually vary by 3db however... I will agree with others, this is not the cause of your attenuation and playing around is more likely to induce a fault than lead to any benefit.