Drop of SNR in working hours

[#1]

Another capture with wireless off (for at least 20 minutes) attached for completeness, also an example of the incomplete page loading.

[#2]

Each time the reduction is gradual over a period of 30 minutes, but recovery is instant. Progressive onset as some apparatus warms up comes to mind, with instant switch off at the end of the working day. Start time seems late for an industrial cause, more likely home working or perhaps shop/office.
Is there any activity in the locality that might fit that profile?

[#3]

I wholly agree with your thoughts Spraxyt but I cannot think of anything local to home, more likely on the route to the exchange somewhere.
Does anyone think that BT engineers would be able to investigate and rectify the source of the 'noise'?

[#4]

I imagine a specialist REIN engineer would be able to identify such a source. In your case (I assume) it's every weekday, and persists through the day, so not pot luck that it's there when the engineer visits. However if a fault is raised there is a risk that the BT solution would be to turn interleaving on and increase your target noise margin to (say) 12dB so that it remained high enough through the day.
Do you know any amateur radio enthusiasts who might have interference detection kit? Or an AM radio tuned to around 612kHz might identify static.
Alternatively how about trying a fixed 9dB target noise margin?

[#5]

Unfortunately I don't think it's every weekday but it has just returned to 'normal' and webpages are now loading in a reasonable time

[#6]

I notice you mentioned your sync rate is high but have you run any speed tests during these times?

[#7]

Further thought - what does the bit loading plot look like during the quiet and noisy periods? Wondering if this shows interference (dips?) at any particular frequency.
Routerstats has the ability to plot that picture on the TG585v8.

[#8]

I'm running Routerstats 6.6 but I could not find settings for the 585V8 so it's currently manually configured just to read SNR and Sync, I cannot currently find a way to get a bitloading graph with this router - any hints gratefully recieved.

[#9]

Setting routerstats up by selecting the ST585 v6, v7 radio button on its configuration page and entering router login information works on the v8 also. The configuration defaults should work without additional manual configuration.
Does your menu strip look like the one shown in the attached image (from a v8)? I've highlighted the bitloading tab.

[#10]

There are useful hints for configuring Routerstats in anotherone's posts in this thread.
Be aware those posts were made for an older version of Routerstats, and integrated set-up for the TG585 did not exist. However the suggestions for setting up the graphs and capturing them remain valid.

[#11]

To Jojo,
I tried a speedtest this afternoon it took 10 minutes to get to 40% then stopped and had progressen no further after another 30 minutes.
Trying to attach now, in case upload is still OK.

[#12]

HI walker23,
I'm thinking it may be contention. Although we usually see this in evenings and weekend it could be that there are a lot of business users on your exchange. Do you think that could be possible in the area you live. The only other thing I can think is that it may be a REIN issue caused by a local company. My instincts say that it has to be something to do with local business. In any case you should definitely raise a fault.
Jojo

[#13]

SNR margin just jumped to 5.5 and the speedtest worked.
I don't think contention should cause a drop of margin of around 4dB then suddenly recover
BT Speedtest completed at 17:35, prevoius attempts just gave error

[#14]

Fault raised: id=40497666

[#15]

Did you manage to get the bitloading plot to work (see replies #23 and #24)? The bitswaps vs time plot might prove "interesting" during noise onset/reversal. Sadly, however, if it behaves as I anticipate it only shows effect but not cause.