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Technology Stocks : The *NEW* Frank Coluccio Technology Forum -- Ignore unavailable to you. Want to Upgrade?

To: elmatador who wrote (4539)	12/7/2001 1:38:11 AM
From: Frank A. Coluccio	Respond to of 46821

I'm just guessing, but I suspect that they are applying a constant direct current of approximately 30 to 40 milliamps on the loop that has only one load coil on it. This would radically reduce the inductive effects of the load coil, by near-saturating its toroidal core (maximum magnetic flux). In this way, undulating direct (varied by the bi-polar, or native DMT or CAP) could still pass over the loop, but the load coil would no longer have an inductive effect, thus negating the low-pass characteristic of the load coil. Crude. But if it works? What the heck. We no longer live in a world where pristine engineering principles matter as much as they once did, if the product performs in a manner that is said to be 'good enough.' Right? ;-) But like I stated above, I'm just guessing. I have some basis for citing precedance here. When I was experimenting with sealing current (with Bell Labs during the Seventies), we noticed that increasing the level of d.c. on loaded loops (but not over non-loaded loops) had the secondary effect of altering the pair's frequency response, allowing higher frequencies to pass when greater amounts of current was applied to the loop. "Sealing current," FYI, was applied to twisted pair loops for the purpose of electrically binding poor mechanical splice points on main frame cross connects and in manholes that would otherwise result in flaky intermittent "swinging opens" or predictably degrading signal level problems. Noise conditions managed to sneak in there, too ;) when one side of the pair (tip or ring) went partially open (bad connection), and the other side of the pair, didn't. FAC