A Client of mine, a nation wide T.V. Cable Company brought me out to a site to check for voltage on the interior RG-6 Coax Cable.
(2)Two apartment complexes have the similar problem out of (10) complexes.
Each complex has a (12) twelve combo meter panel. The sub feeds to each apartment are in romex or service entrance cable, that run down a rafter bay.
We think the RG-6 shares the same rafter bay.
I am reading any where from 18volts to 45 volts to ground with a simpson 260 sieries 8P meter on the shields & cores of the RG-6 when isolated from the incoming service.
The shields are bonded to the main service U-Fer ground during nomal operations.
Apparently it is effecting the High Speed Internet modems. The complex is about 15 years old and the problem had only been revealed with the increased customer High Speed Connections.
Any sugestions appreciated.
Bartlett Electric Inc.

Gidday there,
This problem definitely sounds like an induced voltage problem.
It sounds like the coaxial cables have been installed very close to the Mains wiring.
I'd recommend that the coaxial cables be segregated from the Mains wiring by at least 3ft.
Let us know how you get on.

Mike :}

Are you sure all of the coax shields are bonded? If there are bonded at the building entrance, the only voltage you should see would be the result of voltage drop from current flowing in the shield. I doubt if you have this much current. I'd be checking for poorly installed coax connectors that did not maintain shield continunity.
Don