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[waltergmw]

Gentlefolk,

I thought you might like to hear this somewhat better tale as it could be a tip for use elsewhere.
As usual it started with yet another terrible line suddenly disappearing, just as the poor fellow was filling in his umpteenth job application.
I had a panic call from him at 18:30 and hurtled over with a spare 2700HGV - he was using a Thompson 585 V7 but it had lost sync.
After 20 mins we managed to sync with the 2700, so off went his latest CV.
The first BT O engineer replaced the entire external cable with drop wire 10 (thicker conductor) and a new SSFP.
His JDSU instrument wouldn't sync even after all his work but thankfully our 2700 still did.
Our favourite BT O engineer arrived a few days later and had the brilliant idea of putting RF3 filters on the two lines ex the same DP, running into the adjacent Thames Water pumping station that seemed rather noisy.
Result an immediate increase of sync from 288 to 704 Kbps. The throughput isn't fantastic but at least the fellow stands a chance of getting a job.

Kind regards,
Walter

[attachment deleted by admin]

[burakkucat]

Even to my untrained eye, the second bitloading graph shows a clear improvement over that of the first.

That was a smart piece of lateral thinking by the OR engineer, to install those filters. Just one question, to satisfy my curiosity. Who determined that the water pumping station was radiating noise down its telephone / telemetry lines? The result of your methodical investigations, Walter or was it the OR engineer?

[waltergmw]

@ Burakkucat,

I must admit to starting it ! Some may know I keep a regular watch over the unclean in our area and we have even tried THREE times to give BT a contribution to install a much shorter 400 m loop instead of the 1.2 km that the route takes now. This is the second such incident in a few months. You only have to look at the attenuations to see the signal strength on lines of up to 8 km are going to be absolutely microscopic. With no noise you can get a satisfactory sync speed of around 2 Mbps as indeed we get on an underground branch of the same cable. However this loop, high on a hillside, is notorious for its difficulties and there are about another 20 lines that just cannot cope with the laws of physics.

Back to this case. It had been running sub 250 Kbps from the start but in Mid April it went south in a big way at about the time I saw Thames Water engineers looking at their panels in the kiosk. We mentioned that to the O R engineer who got his wireless out discovering general noise in the area but could not pinpoint the culprit. The genius bit came from him when he decided to try the RF3s in the BT 66 box on the drop pole. I am still unclear as to exactly how the filter should work in the reverse direction but it certainly achieved the result. @ Ezzer & RP - is this a practice that is commonly employed ?

Kind regards,
Walter

[Ezzer]

RF3 in a bt66, externaly ! sounds a bit iffy as the rf3 could become prone to corrosion in the long term. I havn't heard of fitting rf3's externaly. Although my old test nte had an rf3 that I fitted via an 8PDT switch so I could check if an rf3 would make any difference at a flick of a switch. And the test nte was one rigged so I could use it anywhere on the network.

I would always try and fit the rf3 as close to the nte as possible so as much wiring is filtered as possible. havn't heard of rf3's being fitted anywhere else on the network. Particuarly as you can't see rf's using a mole (thinks back to having to remove 2 suspended ceilings a fan heater and mountains of sooty insualtion in a pedicure shop to find a 15a filter  )

But then again a lot of broadband fixes I discovered by accident or learned off others who had done the same. Maby by having an rf3 further from the nte was just a case of finding the right harmony in the wiring to help with the interference. Bit like cutting tails off the back of a socket to find the dsl is all of a sudden syncing

[waltergmw]

Thanks Ezzer,

He did have his sealant gun with him so he was of a like mind.
One day, probably when I'm gone, we might have universal fibre.
Then the problems will mainly be mechanical fragility ones.

Kind regards,
Walter

[razpag]

Concur with Ezzer ..... although it's cured the problem, the RF3 filter is for INDOORS use only, and should be fitted ideally where the DW/UG feed enters the premises. It may take time, but it will be susceptible to corrosion where it is now. Also, if the job was udited, the engineer would be getting a big slap on his hand right now.

[burakkucat]

I can appreciate both "sides" of this tale. On the one hand, the official, as exemplified by Messrs RP, Ezzer & Lord Gumble and on the other, the unofficial, that of the user, Walter and myself.

As the OR engineer has stepped beyond the official guidelines to help the end user, let us hope that no fault develops at any time in the near future -- that can be attributed to his ingenuity. 

In a way, it is rather like the rear part of an NTE5A. That is the exclusive domain of OR and its engineering staff. However there are people, like myself (who knows that there is continuity between the screw terminal marked "B" to "2" & "A" to "5" -- reference a previous thread where Mr RP said it has been a long time since he bothered about pair polarity), Walter and Eric (for example) who have experience where none is to be expected! 

[waltergmw]

Hi everybody,

In defence of our splendid O R engineer I'm sure that he has filled the internal-grade boxes with sealant to reduce any possible corrosion effects to the minimum.

On the wider political issue the engineer has now quite clearly found a major cause of noise, but I doubt if many involved in this brouhaha have the energy to insist OR investigate the problem in depth and cure it properly.
This is especially so on an 8 km line without any Universal Service Commitment. Imagine what the EU is going to say if BT insisted on disconnecting him from any chance of making on-line job applications ?
I'm afraid that using an ageing*** low frequency twisted pair network for mid frequency data transmission is bound to throw up these kinds of difficulties which are likely to become even worse over time until the nation insists FTTP is provided everywhere.
Remember Infinity can never be reached and is an entirely inappropriate long term bodge in these circumstances.

EDIT **** The drop pole in question is dated 1947, but obviously has later plant installed on it.

Kind regards,
Walter

[burakkucat]

EDIT **** The drop pole in question is dated 1947, but obviously has later plant installed on it.

Still in situ and used, sixty-four years on. I am very impressed. I assume the local felis domesticus have not been using it as a regular clawing-post!

[roseway]

It may well be just be held up by the wires. As I mentioned here a short while back, a drunk driver crashed into an electricity/telephone pole near my house, and completely severed it at the base. It must have been rotten for that to be possible, I would have thought.

[razpag]

All poles have a test cycle of 13yrs. There should be a green label attatched to the pole, with the month and year punched out as to when it was last tested.

[waltergmw]

@ RP,

We had to have a man hoist on 2 days as the inspection date was more than (I think) 6 years ago.
Here's another "youngster" which is dated 1951.

Kind regards,
Walter

[attachment deleted by admin]

[razpag]

Hoists (Cherry pickers), have to be utilised for various reasons. If there are low wires (Under 5.2Mtrs from road to wire), if there is a red letter 'D' on the pole, if there are red 'SD' letters on it, if there are spiked railings within a metre of the pole and on the same side as the block at the top of the pole, if the pole is dated 1997 or less and hasn't got a green test label on it, ............... and if the engineer decides as part of his own risk-assessment that a Hoist is needed. 

[razpag]

@ RP,

We had to have a man hoist on 2 days as the inspection date was more than (I think) 6 years ago.
Here's another "youngster" which is dated 1951.

Kind regards,
Walter

As you can see, the pole here in your photo was last tested in September 1996, ergo, out of test cycle hence the engineer would be unsure if it is safe to climb. If he HAD have climbed it, and a retrospective audit of his job was carried out, he would be in extremely severe trouble and put on a major disciplinary. There are NO grey areas with safety and BT/OR don't tolerate any breaches.

[burakkucat]

Would either Walter or RP enlighten me how one determines the age of a pole, i.e. the date it was installed, please?