[Amps] use or not coaxial audio cable to transmitter's

[tzikas tzik]

here you can see all of you a schematic from my transmitter installation
http://tzitzikas.site90.net/files/temporary/block_diagram.pdf
I must use ground rod at the end of RG214 (at the feed point) because i have
connect a 2.5mH choke between antenna's feed point and the cable of ground
rod to ground the static high voltage of antenna, to protect my equipment.
Do you propose to install a second ground rod and connect it with the other
ground rod?
What length must have at least the ground rod to work well?
thank you very much