Grounding distribution blocks?
 

Is every distribution block on the line supposed to be grounded? I have a Mediacom cable line coming into the house that is grounded to a piece of conduit on the inside of the house. (It is only for the DSL modem now) I have coax going from the attic antenna down to the basement and three distribution blocks on that line including an amplifier. None of those are grounded. Should they be and how well? I can put a rod in the ground outside and run a wire in to connect to the first 8 output block. Another 4 output would have to ground to the same conduit running around the basement ceiling for lights. The third one is probably too far to ground unless I jumped off an outlet. Would this be overkill or unnecessary since the chances of the attic getting hit by lightning is pretty small?

The cable company system should be completely separate from your OTA system. It sounds as if it is, but I want to emphasize that you want to avoid connecting an antenna to a cable network connection, even if it's just providing internet access. You don't want to interfere with aircraft navigation and communication frequencies or other licensed radio services.

One ground connection will protect all of the OTA coax distribution system. I would only ground one splitter... the one closest to a convenient ground connection. I would use a piece of #10 copper wire (bare or insulated, your choice).

Great. I'll just add a piece of that #10 copper wire to the first distribution block of the OTA system and attach it to the same ground clamp that the cable line uses on the conduit. Otherwise, yes, the two systems are completely separate. Thanks GroundUrMast!