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Thread ID: 142272 2016-05-31 05:50:00 Does phone line polarity affect DSL performance wratterus (105) Press F1
Post ID Timestamp Content User
1421234 2016-05-31 05:50:00 I've not been able to find a solid answer to the above question. I suppose I could test it for myself by reversing the cable pair and checking line stats, but does anyone know for sure? wratterus (105)
1421235 2016-05-31 06:06:00 I'd have thought no, but Silicon Chip magazine had a polarity checker, and suggested incorrect polarity could cause slow ADSL with some modems.
archive.siliconchip.com.au
Terry Porritt (14)
1421236 2016-05-31 06:13:00 In the thousands of dsl lines I've worked on I have never known it to make a difference.Doesn't make a difference to the phone so shouldn't make a difference to the dsl Peter Coleman (597)
1421237 2016-05-31 06:16:00 Wouldn't the phone company detect the reversed polarity - if it was true - and send an agent out to correct it with or without your calling to bring it to their attention?

You've only got one twisted copper pair - right - in Upsidedown land?

That's why you put as Low-Pass (I think, or maybe a High-Pass) filter on the phones - right?
SurferJoe46 (51)
1421238 2016-05-31 06:29:00 Not as a rule. Once upon a time some phones or phone systems particularly older pabxes were polarity concious and had problems like one ring only if reversed. It does cause issues for phones sometimes if the polarity changes between jackpoints and you have multiple phones connected. You really should have the wiring straight within the house at least.The ADSL signal is a balanced signal and filtered off and it's an AC signal so it doesn't really have a polarity so in theory it really should make no difference at all. In practice though weird stuff can happen that doesn't make sense so sometimes it's worth trying the stuff the really shouldn't matter :)

Also the cable pair to your house can pass through several points where it can be reversed and installers while usually consistant in their wiring practices pay no particular attention to polarity at any of them so it could switch back and forth multiple times between the cabinet/exchange and your house. At the end of the day if you ignore the colour there's not really a difference between one wire and the other.

Short version:- No
dugimodo (138)
1421239 2016-05-31 23:00:00 Thanks guys. :) wratterus (105)
1421240 2016-06-01 07:41:00 You've only got one twisted copper pair - right - in Upsidedown land?

Yes but do ours twist the same direction as yours ?? ;)
decibel (11645)
1421241 2016-06-01 16:27:00 They twist in the same direction, but somehow the US twists are much tighter. SurferJoe46 (51)
1421242 2016-06-01 22:13:00 We're just more relaxed is all. Maybe because the internet flows downhill to get here. Plus our wires are metric which clearly works better in the digital age, no Jamming of square pulses into round AWG gauges going on here, so we don't need to wind them up so tightly to compensate. dugimodo (138)
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