public
join:2002-01-19
Santa Clara, CA | reply to tschmidt
Re: Faulty witing or jacks causing DSL issues? said by tschmidt:4) In my case high humidity caused corrosion to build up on a couple of jacks in the basement. This creates a partial short between line 1 and 2. Interesting it was not enough to affect voice but it completely killed DSL, even using a splitter. That should not happen. A splitter completely isolates dsl. There must have been another fault in front of the splitter.
And it is a bad idea to use a microfilter as splitter. The caps will short in time, and the inductors partially saturate reducing filter action. |
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 nunyaWho is John Galt?Premium,MVM
join:2000-12-23
O Fallon, MO
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1 edit | A splitter *does not* completely isolate the DSL. A short / ground @ 2000 Hz is a short / ground @ 50,000 Hz as well. A DSL filter / splitter is simply a low-pass filter circuit.
The OP needs to have their trouble cleared, then worry about filters and splitters. |
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 tschmidtPremium,MVM
join:2000-11-12
Milford, NH
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| reply to public
said by public:That should not happen. A splitter completely isolates dsl. There must have been another fault in front of the splitter. I respectfully disagree. A splitter is simply a low pass filter that attenuates high frequencies used by DSL so they do not interfere with voice grade equipment. How much attenuation is enough is impossible to determine since voice grade equipment is not tested for high frequency rejection. Values were chosen so that in most cases with most equipment it is good enough.
In my case the short unbalanced the line. Filter has no effect on that.
/tom |
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 49528867Premium
join:2010-04-16
Fort Lauderdale, FL
kudos:3 | reply to public
said by public:And it is a bad idea to use a microfilter as splitter. The caps will short in time, and the inductors partially saturate reducing filter action. That is incorrect, an in-NID splitter internally utilizes the same design as a distributed or "microfilter" splitter.
Wayne
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Certified Kwanon fanboy since 1971.  |
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public
join:2002-01-19
Santa Clara, CA | said by 49528867:said by public:And it is a bad idea to use a microfilter as splitter. The caps will short in time, and the inductors partially saturate reducing filter action. That is incorrect, an in-NID splitter internally utilizes the same design as a distributed or "microfilter" splitter. Usually it does not. There are many different versions of microfilters, the cheapest use 2 tiny inductors, 1 100V cap, no fuses.
Good external box splitters use typically 4 much bigger inductors, at least 200V caps and fuses. |
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49528867Premium
join:2010-04-16
Fort Lauderdale, FL
kudos:3 | said by public:Usually it does not. Bullcrapo.
I take you have never seen the internals of a non-epoxyed DSL NID sled.
Wayne
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Certified Kwanon fanboy since 1971. |
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