nutty
1,214 posts 09-03-2017 8:02pm
jea48,
The main rod was installed when the house was built. It was installed as the main ground for the home. However as you suspected, it is within a few feet of the main service panel and the Phone and CATV service is all there as well. The main rod is grounded with a large solid wire, 8 or possibly 6 awg. I ran new leads for the phone, CATV within the exterior boxes as well as hard wiring it directly to the main rod. The results were the same. The (((hum))) was present until I removed the coax from the system.
jea48,
By re-grounding- I removed the old grounding connectors, (both phone and CATV) at the grounding rod and at the exterior (outside) cable junction box. I Cleaned the stake with a wire wheel, (to remove rust or oxidation) and reinstalled new 12 awg solid ground wire and connectors.
I still had the (((hum))). With the system on and the volumn at a reasonable level, I disconnected the coax from the cable box and the (((hum))) disappeared.
nutty,
But did you clean the connection on the ground rod, the ground rod clamp, and the solid #6awg copper ground wire for the electrical service? If not how do you know the connection was not corroded? You want the best possible connection you can get/make to the #6 copper ground wire. The other end of the #6 wire is terminated on the neutral/ground bar in the main electrical service panel. The neutral/ground bar is where all the equipment grounding conductors, wires, are connected/terminated.
(Assuming the main disconnect breaker for the electrical service is mounted in the electrical panel)
What you want, need, is zero resistance, (as close to zero as possible), continuity, between the safety equipment "U" shaped ground contact, (of the wall receptacle your audio video/equipment is plugged into), and the CATV coax cable shield/"F" connector that connects to the CATV receiver box.
Instead of connecting the ground wires, for the phone line and CATV coax cable, to the ground rod you should have connected them to the #6 ground wire for the electrical service.
You could use one of these to connect the two wires to the #6 wire. Install it above grade so it can be inspected. Clean the area on the #6 wire with sand paper where you will be installing the ground termination device.
http://www.gordonelectricsupply.com/index~text~5979096~path~product~part~5979096~ds~dept~process~sea...If you are still living at the same house I would recommend you re-terminate the phone and CATV ground wires. Pick up an Intersystem Bonding Termination as shown in the link above.
You could also use a couple of split bolts instead. See my earlier post for a link.
Though the
Intersystem Bonding Termination
meets NEC code.
Jim
