Claymore
10-01-2006, 10:55 AM
How vulnerable are ADSL devices to lightning? I don't know of any blown through the phone lines yet, while normal modems seem terribly vulnerable.
View Full Version : Vulnerability to lightning
telkomsuig
10-01-2006, 11:24 AM
I have had one blown a few months ago... luckily my adsl "modem" is seperate from my router so it only cost me R400 bucks to replace. I now have lightning protection on the line and power... a Belkin one (Incredible says they will replace any hardware damaged should it not work let;s see)
stoke
10-01-2006, 11:35 AM
I have had 2 splitters die on me - despite using a telephone lightning protection kit and UPS provided telephone line protection on both instances.
But each time the surge stopped at the splitter [destroyed the lightning protection kit and buggered up the UPS's telephone thing].
I'm tempted to use only the splitter as the protection kit :p.
But each time the surge stopped at the splitter [destroyed the lightning protection kit and buggered up the UPS's telephone thing].
I'm tempted to use only the splitter as the protection kit :p.
telkomsuig
10-01-2006, 01:31 PM
I have had 2 splitters die on me - despite using a telephone lightning protection kit and UPS provided telephone line protection on both instances.
But each time the surge stopped at the splitter [destroyed the lightning protection kit and buggered up the UPS's telephone thing].
I'm tempted to use only the splitter as the protection kit :p.
I am not familiar with splitters ... how do they work?
But each time the surge stopped at the splitter [destroyed the lightning protection kit and buggered up the UPS's telephone thing].
I'm tempted to use only the splitter as the protection kit :p.
I am not familiar with splitters ... how do they work?
ambo
10-01-2006, 01:37 PM
I am not familiar with splitters ... how do they work?South African splitters are nothing more than double addapters for a phone line.
When they talk about splitters overseas though - they are generally refering to a double adapter with a filter already built into one of the sockets on the output side. Same as a SA splitter with a filter plugged into one of the double sockets
When they talk about splitters overseas though - they are generally refering to a double adapter with a filter already built into one of the sockets on the output side. Same as a SA splitter with a filter plugged into one of the double sockets
Moederloos
10-01-2006, 01:39 PM
My guess is that ADSL devices are as vulnerable as (analogue) modems, since the line itself is what is vulnerable or not. Once the line picks up a surge, the other devices will die as quickly.
I too have lost a router to a lightning strike, BTW.
I too have lost a router to a lightning strike, BTW.
stoke
10-01-2006, 01:58 PM
My bad - I meant ADSL/POTS FILTER - not splitter - sorry.
ambo
10-01-2006, 02:32 PM
My bad - I meant ADSL/POTS FILTER - not splitter - sorry.I'm open to corrections - but as i understand it the filter is a very basic low-pass filter. ADSL works at high frequencies and voice traffic happens at (relatively) low frequencies. The filter stops the high frequencies from getting into your phone equipment. The ADSL modem also can't handle the lower frequencies of voice but the filter circuitry is built into the modem due to the order in which the different technologies were developed. You may well be able to purchase phone instruments with built-in filters these days - the pots filter is really just a patch to allow the 2 technologies to work side by side.
Gambit
10-01-2006, 04:05 PM
The filter stops the high frequencies from getting into your phone equipment. I was under the impression that the adsl filter is actually mainly for stopping infra and ultra sonic frequencies that are picked up by the phone from interfering with the adsl. ADSL ignores the normal sonic frequencies that the human vocal cords push out but things like background noise and hanging up the phone can generate infra and ultra sonic frequencies that interfere with adsl. Humans shouldn't beable to hear the adsl frequencies at all (even without a filter).
telkomsuig
10-01-2006, 04:15 PM
I was under the impression that the adsl filter is actually mainly for stopping infra and ultra sonic frequencies that are picked up by the phone from interfering with the adsl. ADSL ignores the normal sonic frequencies that the human vocal cords push out but things like background noise and hanging up the phone can generate infra and ultra sonic frequencies that interfere with adsl. Humans shouldn't beable to hear the adsl frequencies at all (even without a filter).
I have super human ears without a filter I definatly hear crackles and squeeks....
I have super human ears without a filter I definatly hear crackles and squeeks....
Gambit
10-01-2006, 04:27 PM
I have super human ears without a filter I definatly hear crackles and squeeks.... Yeah, thats why I purposely used the word shouldn't because people do say they can hear abnormalities on their lines. I don't know if thats to do with cheap substandard equipment (dslam ports or modems) or some people can just hear a higher frequency spectrum than most other people. Can you hear these abnormalities with a filter in place?
telkomsuig
10-01-2006, 06:16 PM
Yeah, thats why I purposely used the word shouldn't because people do say they can hear abnormalities on their lines. I don't know if thats to do with cheap substandard equipment (dslam ports or modems) or some people can just hear a higher frequency spectrum than most other people. Can you hear these abnormalities with a filter in place?
No but I moved recently and the squeeks without the filter was much worse on my previous line... maybe it depends on line quality too...
No but I moved recently and the squeeks without the filter was much worse on my previous line... maybe it depends on line quality too...
habadaba
10-01-2006, 08:30 PM
i (telkom) have lost 3 cards at the exchange due to lightning, 2 times my telephone service was out and once my adsl