BT have messed up my broadband connection, is there anything I can do?

[#1]

Right, I have got RouterStatsLite working after a bit of messing about.  I had to select  Linksys AD241V2 Firmware 2.01.1 as the modem type.  What am I looking for?  It has only been running for half an hour and I am seeing the connection speed stable at 800 with the noise margin mostly on 6dB, dropping to 5 for a sample or two every few minutes and occasionally down to 3.
@Anotherone I have previously tried a different filter with no obvious effect.  I will let RouterStats run for a few hours then switch filters.
I am trying to find another router but no success so far.

[#2]

I have replaced the filter (and power cycled the router at the same time).  It has connected at 896, still with noise margin 6db and attenuation 58.  The noise margin is now dropping briefly to 4 every 5 or 10 minutes but down to 1dB on one occasion so I suspect it will be only a matter of time before the speed drops back.  Image attached.
I have located a spare modem which I will pick up this afternoon, I don't know what type it is.  I will report back when I have tried it.

[#3]

Hello Colin, glad you've got it running OK, obviously the URL for the V2 stats is the same as later V1 versions, I should have spotted that. I'll give you a few tips about settings in another post, but some advice about disconnecting and swapping kit around as you already have a dropping connection.
When you login to the Router Interface, see if you can locate a page that has a Disconnect/Connect clickable link/button for the Internet PPP session, and do the following whenever you need to reboot/resync or swap anything -
Do a Disconnect of your PPP Internet session with the ISP, then wait a few minutes, power down. Then wait 10 minutes (during this time swap any filters, modem/router, connect to test socket, etc. - it doesn't matter if you take longer than 10 minutes) and then power up again (You may need to login to the modem/router and click on Connect to re-establish the PPP Internet session). Check the stats immediately (The Noise Margin [SNRM] shown is usually the current Target Noise Margin).
I usually recommend you do this no more than 5 times in an hour, and then leave it alone for the rest of the day. 
Remember the reason for this procedure is to help prevent the Exchange DLM from thinking you have a worse dropping connection than you have.
As you've already done some disconnecting today, I'd do any configuration of the borrowed modem/router off-line ie not plugged into the filter and then connect up the once and not do any further disconnecting today. Don't want to see your Target SNRM raised from the 6dB it's at otherwise you will end up with even slower speed.
(Also note, you can use the Disconnect/Connect (without a power down) to Gateway hop.)

[#4]

Some tips on settings for RS-Lite. No need to cover Router/URL & Login tabs, you've done that.
On the Graphs tab, as things currently stand you may as well untick the Adjust axis automatically for both Noise Margin and Connection Speed, set the values 12 (max) 0 (min) and tick the plot average value for the Noise Margin and click Apply, for the Speed 3000 max, 0 min and UNtick the plot average, click Apply. Sample 8 secs, 900 Points per page, Click Apply. These setting should give us plenty of "detail" when things are misbehaving.
On the Capture tab, specify the Folder you want to use for the Captured images, I personally use the same folder in which I've installed RS-Lite (C:\RouterStats-Lite) and tick all the boxes apart from the Ping unless you particularly want it.
On the Log tab, tick Enable Log, then type in a file name, I picked RSLite.txt then click on browse and go to the folder you want to save, I picked the same one as the graphs, so C:\RouterStats-Lite\RSlite.txt ends up in the box. Select Comma separated values, no others, and Log every 1 sample. Nothing to change of the Appearance tab.
On the System tab, tick - Minimize to System tray, Prompt before closing, Show noise margin on tray Icon, Show tooltip hints and if you want the Ping plotter tick that. I wouldn't bother with the others and I have a shortcut on my Desktop to RouterStatsLite.exe
When you start RS-Lite, maximise it's Window, so when there are captures they will be full screen size and show more detail, you can then minimise it to the tray and it will run in the background.
What are we looking for. - the way the Noise Margin behaves especially when sync drops. From your previous post the line seems remarkably flat other than the periodic downward spikes. With a long overhead line I would expect to see more variation up and down after dark, but the Linksys only appears to give 1dB resolution which makes things a little more difficult to interpret.
Now the fact that we have these periodic spikes suggests some interference, could be anywhere, but obviously it's an idea to try an eliminate anything local. First have you had any new electrical equipment (of any sort - even changed a fluorescent tube) since around the time this recent problem started, or have you had any problems with any equipment. You're obviously in a rural/semi-rural location - no electric fence units very nearby? When you had that first engineer, did he fit or change anything to your sockets or line? Anything else you might think of?

[#5]

@Anotherone, thanks for all the good info.
I got the spare modem (an old Netgear DG834G v3) and connected it up last night.  I was most surprised to see it connect at 1248 (SNMR 6, attn 59) which is the speed my Linksys was connecting at before the engineer arrived.  The new one has run at that speed overnight with the noise spiking down every few minutes, and the base level dropping down to 4 for a few hours but now it is back up to 6.  See attached image.  Now I am even more confused.  Two possible explanations are, as I see it:
1. The linksys modem developed a fault at exactly the same time as the engineer was here, which is what caused the speed to drop from 1200 to 800.  Having replaced the modem it is back at 1200 and in fact the engineer did not do any harm at all and is due a sincere apology from me.  It seems suspiciously coincidental if this is what happened, but the ADSL cable was removed and replaced so I suppose that could have caused something.
2. When I first had broadband it connected at over 1800, over a period of months this dropped to 1200, perhaps this was due to a fault developing in the Linksys, then the engineer made things worse so that it would only connect at 800.  Replacing the modem has taken it back to 1200, but if the problem introduced by the engineer were removed then perhaps it would run back at 1800 again.
The question is, what should I do now?  Obviously get a new modem, but then should I gratefully accept 1200kbpm and get on with life, or is there anything to be gained by further analysis in the hope of improving matters further?
Does anyone have any suggestions which modem/router I should buy?  I just need basic facilities but need good wireless(g) range.  Should I go for one that is DMT compatible?  Obviously I don't want to pay more than necessary.

[#6]

I would go for the Netgear DG834Gv4 or DG834GT both Broadcom chipset so DMT compatible and the latest firmware for either copes with ADSL2+ should it come your way, also runs Routerstats no problem. They have a good reputation for hanging on with low SNRM's and there's firmware about if you want to play (DGTeam). Usually plenty around on Ebay and sometimes Amazon.
As for your speeds, well it does seem to suggest that the LInksys is not functioning as it should, we'll see what else can be done to get your speed up, there should be something and I'm glad the achieved attenuation figures are consistent with the LLC figure. I'll ask you some more questions about your setup in a minute, wanted to post this first.
The DG834v3 you have there has an AR7 chipset and is also compatible with the full version of RouterStats. It would be a good idea if you can have a go setting that up because it can Telnet and we can have a look at the bits/tone allocations.
As far as the capture settings go, etc, use similar to what I've suggest for Lite, but install it in it's own directory, likewise the Capture files etc.

[#7]

I have RouterStats full working on the Netgear router.

[#8]

Attached is Bits/Tones chart.  Off to Google to give me some idea of what it means.

[#9]

What it means is there is something majorly wrong with the line or setup. There are big gaps in the tones that have bits allocated to them and less bits allocated than I would expect to see which is why the speed is down.
What time of day was the last sync, I note at the time of capture the Margin is down to 4db but that could have been due to one of the downward spikes we were seeing.
We will have to do some methodical checking to eliminate possible causes of the problem.

[#10]

Hi guys,
I'm in the office today, if there is anything I can do to help, let me know

[#11]

Hi Chris, thanks for posting, could you run a full copper line test to see if anything is showing that wasn't on the last one? Much appreciated.

[#12]

Hi,
No problem for posting. The Copper is fine, no problems on it at all. From what I can see, a lot of the disconnections could be being caused by the router. Has an alternative been tried?

[#13]

Thanks for the copper test. He's on an alternative now, giving better sync speed than the other which may be faulty, but given the bits/tone allocations there's going to be a need to do quite a few other installation checks first before one can draw any definite conclusions.

[#14]

Quote from: Anotherone

What it means is there is something majorly wrong with the line or setup. There are big gaps in the tones that have bits allocated to them and less bits allocated than I would expect to see which is why the speed is down. What time of day was the last sync, I note at the time of capture the Margin is down to 4db but that could have been due to one of the downward spikes we were seeing. We will have to do some methodical checking to eliminate possible causes of the problem.

It last synced late afternoon two days ago I think.  The margin was running at 4 when the bits/tone graph was captured, with down spikes.  I have attached the graph from when the bits/tone was captured.
Is there a way to make it routinely capture the bits/tone graph?  It is updating on screen every minute but not saving it.  I have clicked everything that looks appropriate.

[#15]

Hi Colin. Thanks for the Noise Margin graph. Can you post the current one please? Was anything electrical switched on that you are aware of around/just after 1100?
On the main Bit/tone tab there is an Options tab. You need to set the sample rate there to 10secs because this also influences the SNRM sample rate with Telnet activated. Can't remember where the capture setting is without looking, but if you right click on the graph you can tick Capture there, either Scheduled or Now. If you leave the 900 points per page setting back on the main configuration Graphs tab it will be 2½hrs on each graph which is OK for now.
Also can you describe your installation. I assume you have an NTE5a Master Socket as per LH picture as you've had recent engineer visits. Do you have any hardwired fixed extension sockets, if so how many etc? Where you modem/router and anything else is plugged in and are you using Microfilters that look like this everywhere something is plugged in.
What type of phone(s) do you you use, do you have anything else eg. sky boxes, faxes etc plugged in?