George... you're forcing me to think way back over twenty five years or more, you know. It's making me squint!
>By the way, there used to be a theory that one needed to "zap" a line with high voltage first and then apply sealing current at low voltage and about 10 to 15 mA.<
I think that it was inevitable that 108 Vdc would be applied before and after its (s.c.'s) application, purely for testing pruposes, if for no other reason. There would have been no *standard* way to get around it, based on the test apparata used at the time. No such thing as low-voltage, low-current dmm's then, except for the use of a WB, but bureau testers seldomly got that involved with bridges. Although I did manage to bootleg them into the picture for repeat offender cases. Everything was more or less ballistic, tho. But I know what you mean.
We used 22 mils, and set it with a variable resistor. Also needed a choke filter to suppress 60 cycle ripple from the PS if I'm not mistaken. Geez, this is really clearing out some cerebral storage space.
>Bell Cos., as an aside, used to use breakdown test sets to force short circuits on paper and pulp insulated pairs with resistive leakage between ring and tip.<
I remember it well.
>They used to put two breakdown sets in series, a total of 1200 Vdc! When they found out about the practice, the safety people at AT&T went nuts. Another of the millions of stories in the Naked City.<
Those crazy Galvo guys were feared more than anything. Everyone would clear the deck when they came onto a mainframe or in a test room.
>What are you doing now?<
My last seven years with the BS was as Liaison between NY Tel and AT&T for special services in Manhattan. Previously I had been in international transmission maintenance with AT&T. I left the BS in '77 and commenced in a career of consulting - way before it was fashionable. I'm president of Digital Transport Inc. in NY, around the corner from the NYSE, now, primarily serving the larger brokerages and banks. Specialty is in large-scale corporate relocations and migrations of trading floors, data centers, etc.
My latent fantasy is to light up the Twin Towers of the World Trade Center with a couple of OC-192's and spread VDSL to every desktop in the joint. Think you could lend a hand in this endeavor? <smile>
Frank |
