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Joined: Jan 2005
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Moderator-Vertical, Vodavi, 1A2, Outside Wire
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My guess then is that the second pair is providing enough capacitance to 'absorb' any induced hum. This would often happen on paging adapters that were connected directly to CO lines. What we did in these instances was to connect a 'half ringer' module from a standard NID across the line to eliminate the hum. Keep in mind that inductive hum can come from the tiniest of stray voltages, especially when a line runs over long lengths of quad (non-twisted pair) wire. This drop wire is just that, shielded quad. With the sheath not grounded, it picks up just about anything out there like an antenna.
https://i.ebayimg.com/images/i/400465573437-0-1/s-l1000.jpg


Ed Vaughn, MBSWWYPBX
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Read the conductors with an ohm meter for shorts, opens and grounds.

What does it sound like with the barn inside wires disconnected?

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There's leakage between the red and yellow and or leakage between the black and green. Put em' together and there is no place to leak to except themselves.

-Hal


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I agree with Hal. I bet if you took a simple VOM meter you'd see faults in that buried cable. Are the NID's one each end of this OPE properly grounded and is shield on the cable itself properly bonded?

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I'd test it, but I'm with Ed.


Retired phone dude
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