On 28/03/11 19:15, Moczik Gabor wrote: <snipped> > Actually telephone is balanced.
Yes, most of the time. Most commonly through correction > Telephone does not use the local ground > at your house, Correct-ish, they often use ground from the exchange . Though there's often non-copper sections between the exchange and your house, even if you are on POTS. Even that is not the full picture of the circuit in any given call. > it's inherently balanced. Interesting opinion. :-) Though I'd have to disagree. Balanced cable pairs are not uncommon, whereas *uncorrected balanced pairs* are extremely rare beasts. At a minimum you would expect to find "loss on one leg" at least intermittently, ditto extraneous signals. > > The term "balanced" is often confused or mystified by electronic > engineers too, but if you drive and receive two wires with equal > impedance, and compare the signals to each other and not to (local) GND, > that is a balanced transmission. > > I suspect some of the confusion (in this thread) comes from the difference between an ideal balanced state, and a non-functioning state. Most 'phone systems are extremely robust, and very few these days are pure copper. More importantly - the 'phone system, particularly the outsiders view of it, is not particularly relevant to the "serial connection" cabling question. :-) Note: the opinions and experiences of telecommunications technicians, and Complex Data Testers may differ from that of textbooks ;-p Cheers -- Tuttle? His name's Buttle. There must be some mistake. Mistake? [Chuckles] We don't make mistakes. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4d92def5.8070...@gmail.com
