Car repairs only

Have worked on it after hours - no difference

There is an external drop wire which goes direct to the master socket

There is wiring for one unused extension from the master

External

Internal

In reply to a post by MHC:

By Garage do you mean a petrol station and car repair type facility?

If so, there is likely to be a lot of RFI (noise) floating around from petrol pumps, control links and other equipment. Is there a time when everything is off and you could try again to see if the Downstream SNR changes or it resyncs higher.

You will still need to look at the Upstream attenuation.

Have you followed the wires all the way back from the master to the incoming location to make sure there is not a device hanging off it somewhere - a modem or alarm?

The internal picture looks like mains cable to me and a power socket.

As Andrew has said that pic does make it look like the mains socket is very close to the master but in the same breath it would seem there is a wall in front of the master socket so how was it put there, the pic makes it look like you would struggle to get a screwdriver in front of it giving me the idea that the setup is not so great.

Any reason why the drop wire is capped outside the masker socket?

Can you physically disconnect the unused extension wiring?

As Mr S has said - a little close to the mains wiring - can you get a picture from further back and also one of the inside of the master.

Not sure what you mean by capped ?

Pic showing layout internally

Inside master socket

WRT to disconnecting the extension wiring I thought plugging in to the test socket had the same effect ?

You are not meant to take it apart that far, just the half plate on the front, and a picture of the wiring on the back of that are needed

At the back of the socket the incoming dropwire has a black cap over the end with the internal conductors protruding. The cap is normally there to help with weather proofing. I would expect the drop wire to go inside the master ...

I can see a pair Or & Wh has been used.

As for the extension, I wanted to be 100% sure it was but if, as your picture shows it is on the faceplate then it will be disconnected. Unfortunately some people will wire the extension to the A&B terminals.

I am starting to run out of ideas ...

Is that a consumer unit just to the right? Can you kill everything except the one socket used for the router/hub?

Back on site again today

No possibility of power off (maybe another time)

Some further info: site is 181M from exchange (as crow flies) and the estimators say about 16MB down

BT insisted I go back to site "for further testing" then did nothing (apart from a line test)

"Line looks perfect"

"5-6MB down is normal and expected"

"40-50db attenuation upstream is normal"

they then closed the call

I see two plug in power supplies in the mains socket - one for the router presumably, can you turn the other one off in case it's an RFI problem then restart the router and recheck upstream speed.

I'm inclined to think it's the exchange end personally. Have you used the line test facility at bt.com or had your ISP run diagnostics on it ? wire issues on the line should be picked up by the copper test.

Please can I ask for the correct capitalisation. It can remove a lot of confusion at times.

b - bit; B - Byte; m - milli; M - Mega.

so the line speed will be given as 6Mbps (6Mb - albeit incorrect still has the right M)

And attenuation/SNR are in dB (deciBel)


5-6Mb may be reasonable for teh line speed with the noise, if you cannot sort it.

But 40-50dB of upstream attenuation is not normal. Upstream should be lower than downstream and typically half the number plus or minus a few is a good start. So a 30dB down would have 12 to 18 dB upstream. 40dB downstream would have 16 to 24dB upstream ...