Grounding Block
 

I've read that the electrical code calls for mounting the lead-in grounding block as close to the point where the cable enters the house as possible, but was wondering if there is any advantage or dis-advantage to mounting on the antenna mast connected to the mast grounding wire? Can a grounding block be mounted at both locations: also, advantages/dis-advantages? Thanks

Grounding blocks are to be installed at (or near) the point of entry into the structure and serve to ground the shield of the coaxial cable to the structure's ground electrode system. The mast should be grounded separately (also to the GES) using the method prescribed by your local AHJ (if any) or electrical codes.

NEC sections 810 and 820 provide specifics that are used in many locations. Your local library probably has a copy. You can also call your local building code inspector or a qualified electrician for guidance.

Please remember that grounding ANY antenna system is no guarantee that you will be immune from a lightning strike. Most 'strikes' happen a mile or more from the actual antenna. it is absolutely necessary to ground an antenna according to code, and this discharges all of the static electricity that builds up in the atmosphere around the antenna, but that does not immunize you from a direct lightning strike. Be sure that your homeowner's or renter's insurance is paid up...LOL

Grounding
 

I agree , It's the charged atmosphere. The grounding of the antenna directs this build up of electrical charge to ground. A 'FULL DIRECT' Strike will , Well I have seen Direct strikes on Tv antennas , electrical lines and electric meters and trees. No need to get all jumpy , I can tell you this , if lightning is going to strike , it will strike any where it likes , no mater if an antenna is on the roof or not. I can also tell you this , If you drive around looking at Tv antennas on buildings and etc. , you will see that at least 90% are not grounded and never ever have a problem.