I've thoroughly researched the grounding requirements of such towers and equipment, but there are still some details I'm not quite sure on. Tower requirement for grounding electrode as per NEC, one for each leg of tower and of course grounding blocks for coax signal cable and current isolation for rotator control wires, all bonded to grounding electrode system.
All reliable sources state the tower grounding electrodes are to be bonded to main structure grounding electrode. I installed a single 5/8" copper-clad steel 8' ground rod some years ago upon discovering that this structure was not grounded AT ALL. (water system is cistern and previous owners had only bonded electrical system to interior copper supply lines! - no earth contact!)
I have been making significant improvements to this structure (my home) for the last 15yrs. and one of the latest built a sizable addition and installed a 100 amp sub-panel. Not quite sure how I accomplished it, since I only this past week did enough reading to understand the why's and wherefores of separating the neutral wires from the grounds in the sub-panel and making sure they are not bonded, and also the proper feeder circuit conductors (3-wire w/gd or '4-wire') all of which has been done correctly. Not long after energizing this sub-panel I did drive a separate and similar ground rod external and near the location of this new sub-panel. During subsequent exterior construction the grounding electrode conductor was disconnected from the grounding electrode and never re-connected.
Bear with me, I'm getting to my question. The TV antenna tower will be in the near vicinity of where the secondary (now disconnected) ground rod is, at the rear of the original structure and on the opposite side where the main grounding electrode is located (near the SEP, a 200 amp distribution panel.)
Would it be electrically acceptable to: (using one continuous #4 copper conductor) reconnect the sub-panel ground to the disconnected grounding electrode then to the new grounding electrodes for the tower and then through to the original grounding electrode at the front of the house? I also intend to drive another 5/8"x8' copper-clad steel grounding electrode at the front of the house and include that in the uninterrupted grounding electrode conductor. My research indicates that good practice now recommends the installation of 2 grounding electrodes to obtain the low impedance expected of the grounding system.
Another way of stating my concern is: Is it necessary or even desirable to have that "auxiliary" ground at the sub-panel? I believe I understand the purpose of bonding all the systems together at one point to prevent a ground loop or the possibility of inducing a current across circuits within the system because of different voltage potential within the system.
I'm no expert but have noticed many contradictory statements and opinions concerning proper grounding of residential structures.