It is either 6 or 10 AWG.
NEC specs.
Telecommunications Systems [Article 800]. The National Electrical Code requires the metallic members of the telecommunication cable sheath, where required to be grounded by 800.33 and primary protectors to be grounded to an electrode as close as practicable to the point of entrance of the cable to the building or structure [800.33]. The grounding conductor shall be insulated and shall not be smaller than 14 copper AWG and it’s length shall be as short as practicable run in as straight a line as practicable [800.40].
In one- and two-family dwellings, the grounding conductor shall not exceed 20 ft in length. Where it is not practicable to limit the grounding conductor to 20 ft, the primary protector can be grounded to a separate 5 ft communications ground rod [800.40(B)(2)(2)] that must be bonded to the power grounding electrode system with a conductor not smaller than 6 AWG [800.40(D)].
Radio and Television Equipment [Article 810]. The antenna mast that supports radio, HAM, television and satellite receiving antennas must be grounded [810.15]. In addition, each conductor (coaxial, control, and signal conductors) of a lead-in from an "outdoor antenna" must be provided with a listed antenna discharge unit (grounding block). The antenna discharge unit shall be grounded and it must be located outside or inside as near as practicable to the entrance of the conductors to the building and it must not be located near combustible material [810.20].
The grounding conductor for the mast and discharge unit shall not be smaller than 10 copper AWG and it’s length shall be as short as practicable run in as straight a line as practicable [800.21].
Grounding of the antenna mast and lead-in cables in accordance with the NEC is somewhat effective in protecting receiving equipment from voltage surges, as well as voltage transients from lightning. If the mast is not properly grounded, the Low Noise Block (LNB), as well as the dc rotor motors that control the positioning larger satellite dishes often will be destroyed by voltage surges caused by nearby lightning strikes. If the lead-in from an outdoor antenna is not properly earth grounded in accordance with the NEC, the receiver can be destroyed by voltage surges caused by nearby lightning strikes.