Yes all outdoor tv antennas should be grounded.
Do attic antennas need to be grounded.
There is an nec requirement to ground metallic objects in a structure likely to become energized such as metal water pipes appliances gas lines etc.
I can tell you that as of the 2004 nec and nfpa 101 which covers life safety codes there is no requirement to ground a receive only internal antenna system.
If it is important should i just tap the coax or is a separate grounding wire needed.
However the connection of your antenna coax to various ac operated equipment in this case your converter box or tv introduces the potential of electric shock.
Check to ensure that the vent tube is firmly grounded before connecting the wire.
Note that the coax is going to be grounded at the receiver anyway.
The antenna is essentially designed to capture that electricity.
Furthermore tv signals are made of electricity.
Antennas mine are receive only for fm tv and public safety bands will be generally restricted to the attic.
The copper wire at the base of the antenna mast attaches to the copper vent tube that runs to the roof through the attic in a 55 year old house.
Even if you have a newer plastic antenna there is metal inside.
There is no requirement to do this for indoor antennas.
For electrical saftey the antenna should be connected to a lightening arrestor and that connected to ground.
How important is it to ground them.
But this wouldn t apply to most attic antennas i would think.
If it is just for reception e g.
In the case of an attic installation your tv antenna will be sheltered from the environment so there s no need to ground it for that reason.
Will their location in the attic reduce their tendency to build a charge and attract lightning.
Transmission antennas and cables i d have to pull the code books and check but i m fairly certain they do not require grounding as well.