Hi folks,
Just wondering if anyone knows why you could have 100v on-hook between two cores in a drop cable? All the other cores are dead, and I'm not on the border of two exchanges (where I suppose I could potentially have two different lines connected to give a double voltage). It's a bit weird if you ask me... Line has been out of service for a while.
Cheers - Paul.
These days it's usually there to power a HDSL unit or a CSU for a T1 circuit.
H.
In the Good Old Days it could similarly have been there to power all sorts of "cxr" boxen. These multiplexers usually used local utility power at (or near) the customer site, but could also be powered from the central office.
("cxr" is the general abbreviation for a "carrier eXchange circuit". While originally these were used for COCO lines, lots of them started appearing in misc urban and suburban developments. If there was, say, a 25 pair cable to the site that later became a big subdivision, the telco would grab a few of those wires and multiplex a dozen (or, as equipment got better, plenty more...) circuits onto them and break them out near the buildings.)
I lived in a building on the upper west side of Manhattan (in NYC). In 1975 or so NY Telephone placed one of these HEAVY suitcases in the basement next to the phone wire block. The wire posts that fed it had large red protectors on them with a tag that said "danger, Will Robinson, carrier voltage present".
(This fed out a dozen wire pairs to the various apartments).
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