There is a good description here
http://www.kitz.co.uk/adsl/rein.htm

I know that 612 khz is often a frequency that is recommended to use with an AM radio to track down REIN but I don't know why that is, as DSL works by using many different frequencies and excluding those with errors / weak signals. So for the best data rates you need an error free wide bandwidth. It may be just that 612 khz is in the right region and is generally free of broadcasting stations.

As to finding it - It was some joint work between an Open Reach engineer and myself. They did have a proper meter but in fact a cheap AM radio worked better. If it had been anything other than the router power supply I like to think I would have found it myself easier. I tried switching everything off apart from the essential things like the router. I even tried another router but stupidly looking back was using the same power supply!!

Jon

Thought you had exactly nailed it, but alas not.

AM radio revealed masive rfi coming from... the 2860's power plug! But when I swapped it for a different one, with almost no rfi around 612khz, no difference to my SNR.

Back to the drawing board.

Mark

markvoip wrote: Thought you had exactly nailed it, but alas not.

AM radio revealed masive rfi coming from... the 2860's power plug! But when I swapped it for a different one, with almost no rfi around 612khz, no difference to my SNR.

Back to the drawing board.

Mark

Well bear in mind that if you're on BT, the Dynamic Line Management makes changes gradually, so if it's thought all this time that there was a noisy line, and then it suddenly detects a clear one, it'll take time to reset itself.

From the output of 'vdsl status' via CLI (ssh or telnet) compare the attainable rate vs the actual rate. If the attainable rate looks like what you'd expect and is similar to any 'vdsl status' you may have saved previously then it's probably DLM and will rise once things have been stable again.

If the attainable rate is close to the actual rate and the actual rate is much lower than you expect/observed previously then perhaps there is some interference either locally or between your house and the street cabinet.

Never used the CLI. TVM for the suggestion.

Pleased to say it reports DS Actual rate 62.3 Mbps, DS Attainable Rate 72.8 Mbps with the later being what I used to get.

BUT... I (temporarily) swapped back the noisy Dratec psu and got similar figures. I would have expected an instant drop in the 'attainable'.

I am really grateful for all the excellent advice I've been given here - thanks folks.

Mark