Jeff,
The Bell System used a metal box full of batteries that totalled 600VDC.
There was a VOM and Wheatstone bridge in the set with a reversing switch and a "fire" button/switch.
United Tel used a similar device PLUS an AC transformer box...now that would dim the lights
:.
Yes, they could be dangerous. If a 50 pair cable were to be "broke down" all 50 pair would need to be isolated at the main frame. Otherwise this voltage would end up in the switch gear of the CO.
The main reason the break down set became obsolete was PIC cable. Break downs were designed to operate in paper cable. The PIC cable was hard to melt down vs. the ease of burning down paper when it is wet.
Plus the 710 Dynatel was a portable Wheatstone bridge with mechnical computer.
Daytron 710 or 4510 was another manufacturer.
Same principle as the Dynatel.
Then Badger came out with one of the first cable OTDRs that did the fault finding.
Similar to the Dynatel 730/735.
Anything else?
