It doesn t support what you want to do.
Grounding an antenna in attic.
From your description it sounds as if you may create a ground loop which may cause problems throughout the house.
The mounting rod is insulated from any of the active reception parts.
Run a length of 6 jacketed stranded ground wire from whichever you installed there directly to your bussbar.
But first check the electrical plugs of the various devices attached to the tv line.
Stick to the building code.
So there isn t any ground from the tv either to bleed off any voltage that might pass through the antenna.
Neither apply to an antenna in the attic.
Then on a separate lug on the bussbar run jacketed stranded 2 ground wire outside and straight down the side of the house to a ground rod sunk at least six feet below ground eight feet would be better.
Securely fasten the grounding wire to the side of your house using staples or other zip screw type wire clamp suitable for the job.
If you need to bend the ground wire make the bends as gradual and as smooth as possible.
There is no requirement to ground an attic antenna in the national electrical code.
You should therefore strongly consider grounding your attic mounted antenna by attaching a grounding block to the coaxial cable to shunt off excessive leaked current.
There are very specific requirements for grounding an antenna both via mast ground and a shield ground.