On Mon, 04 Feb 2008 06:55:45 GMT, "EpsilonRho" wrote:

:
:The typical POTS line dc condition is simply the battery feed retard which
:is
:usually a 200ohm + 200ohm balanced high Z transformer.
:
:Essentially, behind one of the 200ohm windings will be -52V dc and behind
:the
:other 200ohm winding will be +ve. Remember that the +ve side of the
:exchange
:battery is connected directly to ETH. So, at the customer premises the +ve
:leg
:will have 1/2 the line loop resistance plus the 200ohm retard to ETH and
:the -ve
:leg will have a similar line resistance + the 200ohm retard to -52V.
:
:Thanks for this info. What you are saying is that the DC resistance and the
:AC impedence should be the same on TIP and RING.


Assuming your line has been constructed using a uniform cable pair and all
intermediate joints are properly made it will have equal resistance in each leg
between the exchange and the demarcation point at your premises. AC impedance of
the line is not an issue as long as the dc conditions test ok.

The telco will be able to determine if the line is ok for telephone service
using their automatic line test. They will also be able to determine if the
cable pair is capable of acceptable DSL operation.