'Normal' evening SNRM drop/flat twisted pair RJ11 cable.

[#1]

Because my BT master socket is downstairs and my router upstairs, a couple of years ago I bought a supposedly high quality, twisted pair 15m RJ11 extension cable from Amazon, which I carefully routed and clipped as far away from any obvious domestic sources of interference as possible.
Having swapped to a TG582n recently and therefore no longer able to manually tweak my SNRM, the DLM in its wisdom has settled on a target of 6dB, which rises to up to 7 during the day, but falls to 4 or even slightly less during the evenings.on my 37.5dB attenuated connection.
The extension cable has a flat profile, although without being able to see the outline of the wires inside (and deciding that chopping through it to have a look was a bad idea  :D) it's impossible to tell whether it is actually twisted pair or not.
My ADSL2+ connection is of reasonable speed and stable with these margins, but no-one wants to lose any speed if it's avoidable, so 2 questions really:
1) Is a daily variation from 7dB to 4dB (~40%) in SNRM between best and worst in the range of what could be considered 'normal'?
2) Is there some chance, or no chance, that a flat profile RJ11 cable is in fact twisted pair?

[#2]

Quote from: JayG

1) Is a daily variation from 7dB to 4dB (~40%) in SNRM between best and worst in the range of what could be considered 'normal'?

The target will be 6db, so variations from 4 to 7 aren't something I'd be overly concerned about really.

Quote from: JayG

2) Is there some chance, or no chance, that a flat profile RJ11 cable is in fact twisted pair?

Without looking it's not going to be easy to tell.
Can I ask why you decided to run an extension to the router, rather than a long ethernet cable from the router? Doing it the alternate way would have meant the router stays next to the master socket and would rule out the majority of internal interference.

[#3]

Having the Modem/Router where you can see it is a far better idea than having it remote, especially if you want to use several ethernet outlets.
That cable having a flat profile is undoubtedly NOT twisted pair and this will most like be contributing to the greatest of the SNRM variations.
I'll find you a link of something suitable.

[#4]

Quote from: Chris

Quote from: JayG 2) Is there some chance, or no chance, that a flat profile RJ11 cable is in fact twisted pair? Without looking it's not going to be easy to tell.

Not easy to tell even looking very hard indeed (x-ray specs required!)

Quote from: Chris

Can I ask why you decided to run an extension to the router, rather than a long ethernet cable from the router? Doing it the alternate way would have meant the router stays next to the master socket and would rule out the majority of internal interference.

At the time my upstairs PC was my only 'device' and I wanted to be able to see what the router was doing - now that I have a tablet as well which I tend to use downstairs I might reconsider my options, especially if someone advises that there is no such thing as cheap flat twisted pair RJ11 cable! 
+ + +
Thanks Anotherone - will keep viewing. 

[#5]

Quote from: JayG

Is there some chance, or no chance, that a flat profile RJ11 cable is in fact twisted pair?

Some chance I would say, though I've never seen it with RJ11.
I do actually posses a length of flat Ethernet (8-core) RJ-45 terminated cable designed to run under carpet and it does indeed contain twisted pairs.
This is fairly obvious as it does get somewhat distorted and you can sort of see the cores twisting through the sleeve.
If it just looks smooth 4-core then I'd agree with Anotherone and say it's not twisted.
But moving the router would seem sensible if it can be done. You can run 100mbps Ethernet over 4-core phone cable (CW1308) no problem. I do.  

[#6]

OK, this is what you want. As you can see from the picture the cable has a round profile. Cat5e cable has a round profile.
If you were to receive a flat cable on ordering that I would be immediately demanding my money back and costs under the Sale of Goods Act as not fit for purpose and not as described - any argument go straight to Trading Standards.
If you have any evidence of what you ordered before and the supplier and any receipts, I'd consider contacting them if it isn't going to cost you and tell them you've discovered it isn't what was described and see what they have to say. Any brush off, tell them you will take it to Trading Standards. When you done the replacement, take all the evidence to Trading Standards.

[#7]

Flat ethernet cable as described by HPsauce is not that common but is fairly easy to distinguish from the standard "telephone extension" quality cable as he's described.
As you are re-considering the position of your modem/router then make sure that you decide on the basis of getting the best wireless signal for your tablet (nothing else). Try the modem/router in both locations and see what works best for the tablet in the places you want to use it. Don't forget to make sure you pick a wireless channel that isn't getting zapped by neighbours' wireless routers.
If you decide next to the master is best, then you can either buy a suitable length Ethernet Cable with RJ45 plugs to connect to your main PC or make one up as suggested by HP as you can get away with CW1308 cable but you'll need to buy the cable, & plugs + a crimping tool, or sockets and short Ethernet patch type cables. Personally, it would be cheaper (and easier) to buy a ready made Ethernet cable especially if routing it is not a problem.

[#8]

Agreed. I just happened to have an old phone cable covering much of the 25-metre route I needed, so I removed that and installed new CW1308, SWMBO has never noticed the change.  
I already had the means to terminate and crimp in my "box of bits" so that wasn't a problem.  
Terminating after laying the cable also helped as I used a couple of drilled holes at "strategic" places.

[#9]

I've found the order for the current extension cable and at the time (3 years ago, and still is) it was described as "15m ADSL Cable - Premium Quality / Gold Plated Contact Pins / High Speed Internet Broadband / Router or Modem to RJ11 Phone Socket or Microfilter / White" - i.e. everything a not-very-techie person would probably believe they should be looking out for, but of course no mention of being twisted pair, because it no doubt isn't. 
Although I've yet to wander round everywhere in the house and back garden with the tablet to decide on the best router location for overall Wifi reception I suspect that it's better left where it is, especially for the latter area (the signal would have an extra brick wall to go through.)
Anotherone: The item in your link looks like the real deal, and at that price it would be rude not to buy it and give it a try - who knows, I may get down to a 3dB target SNRM - thanks all. 

[#10]

@HP, yes I remember you saying - keeping SWMBO happy can always lead to a more peaceful life 
@JayG, as you say, no mention of twisted pairs, so it will be just high quality radio & interference receiving Cable
I agree, at £3.99 the Cat5e cable one is worth a try,  you have the Sale of Good act to protect you should you need it. Good luck with the 3dB Target 

[#11]

Hopefully this thread will help at least a few others concentrate on what the glossy descriptions don't mention! 

[#12]

Quote from: JayG

Anotherone: The item in your link looks like the real deal, and at that price it would be rude not to buy it and give it a try - who knows, I may get down to a 3dB target SNRM - thanks all.

Just had an unprompted resynch which presumably is the DLM deciding to have another go at a 3dB SNRM - the 'proper' twisted pair extension cable is still in the post, so I don't think there's much chance these stats will still be valid in about 6 hours time! 
Uptime: 0 days, 0:05:13    DSL Type: ITU-T G.992.5
Bandwidth (Up/Down) [kbps/kbps]: 1,171 / 13,035
Data Transferred (Sent/Received) [MB/GB]: 507.57 / 6.34
Output Power (Up/Down) [dBm]: 12.5 / 0.0
Line Attenuation (Up/Down) [dB]: 20.6 / 37.0
SN Margin (Up/Down) [dB]: 5.2 / 2.6
System Vendor ID (Local/Remote): TMMB / ----
Chipset Vendor ID (Local/Remote): BDCM / IFTN 
Loss of Framing (Local/Remote): 168 / 0   
Loss of Signal (Local/Remote): 19 / 0 
Loss of Power (Local/Remote): 0 / 0 
Loss of Link (Remote): -   
Error Seconds (Local/Remote): 118,605 / 1   
FEC Errors (Up/Down): 0 / 199,999   
CRC Errors (Up/Down): 0 / 14   
HEC Errors (Up/Down): 0 / 39
In the event that the new extension cable does enable me (and my pal DLM) to operate reliably at a 3dB SNRM I'll let you know - I'm certainly having a much more entertaining ride with the TG582n than the 'tweaked' old Netgear!. 

[#13]

What version firmware has that 582n got on it?

[#14]

10.2.2.B

[#15]

Ah, OK, not 8.4.4.J then, that's good.