Originally Posted by rabbit73
Even though it is not required by the NEC, I feel that it is a good precaution to ground the coax shield even for an indoor antenna. I have had three close calls with electrical shock...
I have also been directly shocked many times off full line voltage by accident. It Herz!
Actually it is a small miracle that I am alive at all given that once I was shocked by an ungrounded and leaking pool pump that I switched on with a metal bat-handle toggle while standing barefoot in mud. It was probably just the momentum of my moving hand, my right-handedness, and the resistance of the ground fault through a trickle of leaking chlorinated water that spared me. The belated response of the parents in the home was, "Kids, let us switch on the power because the pump is leaking and it shocks people." Yup, that fixes it!
The other times I got shocked it was my own fault for being careless while troubleshooting or wiring. Once I also stuck the metal tip of a screwdriver into a metal ceiling light box to push the wires aside and blew the tip off the screwdriver with an arc when I cut through the insulation on the wire.
The other hazard that really caught me off-guard was the old black-and-white Zenith tube TV set from the early 1960s, the one with the motorized VHF tuner switch that makes a sound like "zdit zdit zdit" while it rotates through its stops, and also with the two-prong polarized power plug that has the neutral connected to the grounded chassis(!).
That was actually legal when that TV was manufactured because there was no such thing as grounded house wiring or double insulated appliances back then and removing a knob from any of the metal control shafts exposed the 'grounded' chassis. The plug was polarized at the connectors at both ends. It had the TV side of the cord attached to the removable rear fiber board cover with a metal clip so that the integrated power cord was automatically removed with the cover for replacing tubes. Remember those?
An engineer had fitted the Zenith with a DIY composite input and signal source switch on the rear of the chassis to use the TV as a DIY monitor, and then connected the 'monitor' to a three-prong grounded computer via shielded coax.
I unknowingly reversed the polarized and chassis-connected power plug on the Zenith with an unpolarized three-to-two adapter to fit it into an ungrounded extension/splitter and make room for more plugs to hook up the Lionel trains, not realizing (nor could I even understand at that age) that the chassis of the TV was intended to be grounded to the neutral with the polarized plug. I blew a ground trace and diode off the main board of the computer.
Remember the Southwest Technical Products 6800 PC kit from the early 1970s? He had extended it from the 4K ram it shipped with to an amazing 32K with a homemade 8-slot bus-extending daughter board.
You can see from this picture that such an extender does not fit within the case. The PC was sitting caseless and exposed on the work table. I heard the crackle and saw the flash out of the corner of my eye when the ground trace and diode vaporized.
Fortunately I did not get shocked by the wiring fault, and it was a simple repair on the main board, but it makes me wonder why an electrical engineer who should have known better would create such a hazardous DIY setup? He kept using that 'monitor' with that PC for years afterward despite the danger. SMH
Thanks to all for your suggestions. I only asked because I have also gotten tickled several times off coax while attaching lines to splitters in various locales. It was not a big deal, but it was annoying and I was curious what the appropriate method would be to address it since the contractor neglected to.
Regardless of anyone's interpretation of NEC (is it really an 'indoor' antenna if the split wiring exits through both gable vents at either end of the peak and then the split wiring also runs down the exterior of the building before re-entering at a lower level?) there is a potential electrical hazard from leakage that I prefer to address proactively and appropriately. Apparently, any old ground will do, so that's my plan until I have the energy to climb up the ladder into that attic again and ground at the signal source where the connection is unlikely to be broken by future wiring changes within the living space.
PS if anyone knows how to keep an Ubuntu browser from inserting superfluous line feeds on this forum I would appreciate it. I have tired of editing every post to remove them afterward. This time I am posting with only a single carriage return and all the paragraphs are run together in the editor making it tough to read what I am composing.
I guess I will find out in a second if that formats properly...