Joe wrote:
"I would like to use this ground rod to ground my Butternut H9V vertical
antenna."

USA National Electrical Code requires all site ground connections be
connected together. Lacking such interconnections, high transient
voltages of vastly differing magnitudes might momentarily appear at
different ground rods and at circuit points connected to them. This
could lead to injury or damage.

It`s a good idea to provide an antenna ground rod, or rods, directly
beneath the the antenna, and to provide a short stout electrical
connection between the antenna ground system and the electrical service
entry grounding system. The interconnection intends to keep the
potential between grounding systems low. Additional lightning protection
will often be needed.

Best regards, Richard Harrison, KB5WZI