Plugging the router at the master socket and/or at the end of the CAT5 extension run gives the same readings.
I can't say that any of the results are significant. However I like your experimental style. :)
I think Walter may be interested to see your null results because, quite some time ago, he was pondering if earthing the steel reinforcing catenary wires in a standard Openreach drop-cable would provide some degree of screening. (My feeling is no.)
The results would seem to indicate (the 2nd proper earth) that the fluctuations seen are just 'normal variance', but hey some of us like to play and experiment just to see if we can get that little bit more and sharing experiences that may be helpful to others.
What I do intend to try is running the ADSL modem off a battery, then there'll be no mains-bourne or PSU noise getting so near. I need to get the right sized power connector, then I thought I'd connect it to a 12volt portable drill battery and see if there's any benefit.
I don't trust a bank holiday Sunday to have normal noise so I will wait for a proper weekday to confirm that.
That would be a good experiment to perform. I have suggested using a lead-acid car battery in the past, as the idea of using a portable power tool's battery had never occurred to me. :)
Are you absolutely sure of the dimensions? :-\
Maplin (http://www.maplin.co.uk/dc-power-plugs-43084) have a range in stock, in particular 1.3mm/3.45mm, 1.7mm/4.0mm, 1.7mm/3.45mm, etc.
Maybe the model number of the PSU for the DSL-2780 can shed some light?
The DSL-2680 has a PSU labelled AMS47-1200500FB (output 12v DC / 500mA)..
That PSU is from the Global Yeou Diann Electrification Industrified Company Ltd. [1].
Global Yeou Diann trades as Amigo Elec and supplies, amongst others, the following DC barrel plugs with its PSUs..
<snip>
PG-01 Type 10 looks like a good fit..
OD = 3.5mm
ID = 1.35mm
LEN = 9.5mm
If you don't hear from me again, it's because I got the polarity wrong and the modem went pop ???
:hmm: Are you likely to do so? :angel: