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[Weaver]

I suppose that back then in 2004 if we had not been fortunate to have had the really good thick Cu that we did have, then we would have had no possibility of any DSL service at all, not even the 0.5 Mbps fixed rate that we were getting back at first.

Perhaps it just shows you how much can be achieved using really good quality Cu.

Anyway, I suspect the answer to my original question of this thread might be ~ 65 - 68dB or thereabouts but not massively higher.

[burakkucat]

With the little snippets of information that has appeared in this thread and with the help of Google Maps, I now understand the "lay of the land".

[Weaver]

I am at the very northernmost end of the light green-coloured area, the post code is at number six half way down the bank to the sea.

[Weaver]

Btw with the exception of the water board place, between home and the houses near the main road, there is not a single house, nor tree, nor wall, nor any sign of human habitation along the entire run of the line. Presumably this lack of civilisation has to be pretty helpful, as there is no mains near the cable, nor any local source of EM interference, all there is is the ever pervasive more distant AM radio sources.

The cable bundle is lying in water in some places, lying on top of the heather or rocks for a good proportion of the run. It has been buried in some places certainly where needed.

When it gets near to my house, it is on the far side of the road, my three lines depart from those for the rest of the village. My lines ascend a tall wooden pole to gain enough height to cross the road and from there crosses the road while climbing still to a second pole on my side which is much, much higher as my house stands way above the road.

The very last part of the run from the last pole is horizontal at first floor height and radial, and the three lines come straight into the office to the SSFPs by the window with the modems adjacent to them.

[WWWombat]

Generic info only, I'm afraid.

I understand that thinner copper (or lower poundage) can be seen coming out of exchange buildings, when space in the cable chamber or exchange manhole is at a premium. It can (and I guess often is) jointed to thicker stuff as it spreads out - so it isn't a surprise to see it go beyond the standard 0.5mm for the longest, most rural lines.

As this thread shows, some lines are *way* longer than 5km. However, in terms of "electrical length" (aka attenuation), BT says that no lines are longer than 6.5km of 0.5mm copper. Anything that is actually physically longer than this must have some fatter copper in there.

Source: Sagentia, 2008 (pages 3-6).
http://stakeholders.ofcom.org.uk/binaries/research/technology-research/asses.pdf

I recently read something that reckoned the first 1km of copper out of a KC exchange in Hull was 0.3mm.

[Weaver]

I wonder what the record longest and worst Kitizen's link is (ever)?

[Black Sheep]

Generic info only, I'm afraid.

I understand that thinner copper (or lower poundage) can be seen coming out of exchange buildings, when space in the cable chamber or exchange manhole is at a premium. It can (and I guess often is) jointed to thicker stuff as it spreads out - so it isn't a surprise to see it go beyond the standard 0.5mm for the longest, most rural lines.

As this thread shows, some lines are *way* longer than 5km. However, in terms of "electrical length" (aka attenuation), BT says that no lines are longer than 6.5km of 0.5mm copper. Anything that is actually physically longer than this must have some fatter copper in there.

Source: Sagentia, 2008 (pages 3-6).
http://stakeholders.ofcom.org.uk/binaries/research/technology-research/asses.pdf

I recently read something that reckoned the first 1km of copper out of a KC exchange in Hull was 0.3mm.

0.32mm cable is also a common'ish cable used on E-side runs. Most E-side runs are made up of varying lengths of Cu/Al and utilising the various poundage's available.

[Black Sheep]

Found the time to capture a 'Scheme Plan' for one of our Cabs. I've erased a few details but the ones that are left show that this particular Cab is fed via 3 cables from the Exchange, giving a breakdown of what the total cable length is made up from ..... ie: CU or Al, length of that section, and poundage size. 

You'll see 0.32mm appears.

[burakkucat]

Interesting. So three cables, a 200 pair, a 100 pair and a 50 pair.

I am assuming that the third (50 pair) cable has been described "back to front"? I.e. 0.5 Cu, then 0.4 Cu and finally 0.32 Cu. 

[WWWombat]

Very interesting.

I'd read that the thinner gauge cables are used closer to the exchange, to reduce congestion in the chambers into the exchange building - and when you see some of the photos, you understand why!
http://www.britishtelephones.com/gpo/jointbox2.htm
http://www.britishtelephones.com/gpo/cablechamber.htm

Do those 3 entries represent just the E-side - i.e. the cables on the way towards the PCP? It is interesting to see the total lengths differ by 250m!

[burakkucat]

Do those 3 entries represent just the E-side - i.e. the cables on the way towards the PCP?

That is how I have read B*Sheep's words. 

[Black Sheep]

To try and clarify further ..........

The E-side 'Pairs' (Pair of wires) to the Cabs, will be 'Dropped off' from various 4800pr cables. The example I give below sees the total number of 'Pairs' within the Cab being made up from 3 separate cables that leave the Exchange MDF.

Looking at the table, the top one has a total of 200prs allocated from one particular Exchange cable. The second in the list has a total of 100prs allocated from another Exchange cable, and the third one in the list has a total of 50prs allocated ..... from yet another different Exchange cable. 350prs in total.

I have to admit, I'm not 100% sure how the breakdown-order runs, whether it's MDF to Cab or Cab to MDF I do not know. Only our 'Second Stage Repair' and 'Pressure' engineers work on E-side cables. Of which I am neither. If we have a faulty E-side pair, we simply swap-out to a spare pair if available. If none are available, then we pass the task to SSR to resolve.

The only other point-of-note that may be of interest, is the attenuation figures in the right-hand columns. These were taken roughly about the same time Moses was receiving the Commandments, and were determined using a 1.6Khz frequency. From this particular table, we can see that the middle cable would be best to carry DSL signals. We do have an application (SEAM), that gives us the equivalent attenuation readings for a 300Khz signal.

Hope this helps, if not .... ask away and if I can help I will.

Numbers re-edited, to reflect B*Cats astute observations of my original musings.
 

[burakkucat]

b*cat raises a paw to ask how you read the size (total number of pairs) contained within each of those three cables of your example, above, please?

For the first cable, I see "Pair No. 151-350". I interpret that as 200 pairs.
For the second cable, I see "Pair No. 1-100". I interpret that as 100 pairs.
For the third cable, I see "Pair No. 451-500". I interpret that as 50 pairs.

Slightly puzzled. 

[Black Sheep]

Ha ha ........ ye gods ...... my vanity has finally let me down for the last time. I genuinely thought the 'Pair count' was ......................... 151-300 ................ and the 451-500 I read as AS1-500. The letters indicate the 'vertical bar' on the MDF where the circuits are located (Starts A,B,C,D etc etc ........ then AA, AB, AC etc etc ......).

I'm genuinely shocked how poorly I read those numbers !! Pair of bins now welded to my napper !! 

[burakkucat]

Having had his evening meal delayed by examining Google Street View, b*cat believes that he has possibly found Weaver-Land. 

Starting on the A87 to the east of Broadford, I took a long and winding road that was signposted as a "no through road" leading to Heaste / Heasta, five miles distant. Travelling down that road (and taking in the views) I finally crossed a cattle grid and on the left hand side of the road was a sign proclaiming Heasta. (Image below.) Just past that sign is a telephone pole and a cable can be seen leaving that pole, crossing the road to a carrier pole higher up the bank to the left of the big tree. There appears to be another carrier pole to the right of the big tree and then a house.

I shall just say it is a really stunning location as I now depart to eat my evening meal . . .