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| Thread ID: 119067 | 2011-07-03 04:37:00 | Crackling phone lines | rumpty (2863) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 1214398 | 2011-07-03 04:37:00 | It seems that every year round this time our landline phone gets crackling and static noises. I suppose the Winter rains have penetrated to phone cable level by now. Does anyone know what the mechanism is, electrically speaking, that generates all this noise? I did speak briefly (he was busy!) to a Chorus lineman working on our street cable, and he spoke about some electrolysis interaction between the lead covering the cables, paper insulation, and the copper conductors. Amazing that there are still lead sheathed cables around. The whole business sounds like 19th century technology to me. It's all annoying though, talking through all the static, and my ADSL connection speed takes a dive too! This is in suburban Auckland. |
rumpty (2863) | ||
| 1214399 | 2011-07-03 04:54:00 | I have been in the telecom building under the streets of central Chch a few years ago, under there is a huge concrete building fill of air compressors which are blowing compressed air down the old lead and copper pipes because they have corroded so much that moisture and water is coming in. The guy who showed me around said if there are a really heavy rain and flooding, it would bring all communications in Chch to its knees as the air compressors wouldnt be able to keep up. Im guessing it is the same in all major NZ cities, telecom have been reaping the profit and its going off-shore and not investing back into the infrasture for many years.. |
Iantech (16386) | ||
| 1214400 | 2011-07-03 09:26:00 | Very interesting info! I also have a line that tends to deteriorate in the wet (I have to reset the router often when trying to pick up the ADSL and authenticate my details). However, the crackly line and poor performance may also be an ADSL filter that is failing - they seem to need replacing all too often, at about $25 a pop. |
Paul.Cov (425) | ||
| 1214401 | 2011-07-03 12:00:00 | Why don't you just ring Telecom and get them to test the line and fix it if it shows as faulty? | Ofthesea (14129) | ||
| 1214402 | 2011-07-03 13:06:00 | Round here when the phone lines crackle it means that someone has got a bung electric fence. As for crackling in the wet, could just be stray ground current bleeding into the cable. |
ubergeek85 (131) | ||
| 1214403 | 2011-07-03 21:48:00 | I use to get crackling phone lines when it got wet in the winter until one I could ring out but no one could ring me. Rang Telecom and they sent the guys out and found a fault between my place and the thing on the road and replaced the whole cable between me and the road and it has been good ever since. :) |
Trev (427) | ||
| 1214404 | 2011-07-03 22:26:00 | Noise is usually caused by an electrical contact with another line in the cable. It can be anywhere between a few volts and 50v with an accompanying earth. It is usually, not always, caused by moisture in the cable. If your line is noisy there will be a dozen or so other lines near yours with the same fault. All Telecom cables are pressurised, new and old. The cables in Mt Eden, Auckland, are very old and in very poor shape. Although they have attempted to seal the old cables they never seem to be able to seal them completely and so if the cables are pressurised it keeps most of the moisture out. In the days before pressurisation, (1970s) the Mt Eden cables were very leaky and there were many faults caused by moisture. It seemed as though all you needed was a heavy dew and the cables would go faulty. Now that the cables are pressurised, faults in Mt Eden are as few as anywhere else. For the cables to be 100% it would probably mean replacing many of the cables around the country and, of course, Telecom will tell you that they can't afford to do that. After all, they are only making about $1m a day. Much of that profit will be going to the American shareholders which is one of the reasons why Telecom can't afford to upgrade the cables to the standard required for this day and age. Pity the government sold Telecom, eh? |
Roscoe (6288) | ||
| 1214405 | 2011-07-04 06:01:00 | ...Pity the government sold Telecom, eh? I couldn't agree more. The story about the cables being pressurised to keep out the moisture is amazing. Never heard of it before. The bright spark who thought of that idea certainly had a brainwave, and we have had decades more life out of the existing cabling. For better or worse... And no small energy usage, I would think, running the compressors? I wonder how far along the cables the pressurisation is effective? |
rumpty (2863) | ||
| 1214406 | 2011-07-04 07:05:00 | I wonder if moisture will similarly bugger up fibre optics. Moisture around a glass or plastic fibre will reduce the degree to which the light is internally reflected, resulting in more light leaking out. Optic fibres in theory have a shield around their core, but it's still kinda analogous to the old copper wires. Even humidity may have a detrimental influence... all just speculation on my part. |
Paul.Cov (425) | ||
| 1214407 | 2011-07-04 09:00:00 | Much of that profit will be going to the American shareholders Actually it will be going to the Aussie shareholders unless there has been a major change lately. |
mikebartnz (21) | ||
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