I reviewed the NEC antenna grounding rules. It requires two grounding connections for an outdoor antenna. The mast must be connected to the house electrical system ground with a 10 gauge copper, 8 gauge aluminum, or 17 gauge copper coated steel conductor. The coax shield must be grounded using a grounding block that is also connected to the house electrical system ground. The NEC calls the grounding block an ADU (antenna discharge unit). The purpose of the grounding is not to withstand a lightning strike, but to prevent a buildup of a static charge on the antenna system which, in theory, reduces the chance of a strike, and for electrical safety. You can see a diagram of this on page 2 in the AntennasDirect link that GroundUrMast gave you in his
General Technical & Safety Information thread:
https://www.antennasdirect.com/cmss_...structions.pdf
If you use a separate ground rod for an antenna mast ground, then that ground rod must be connected (bonded) to the house electrical system ground with a 6 gauge copper wire. This is to prevent a voltage differential between the two grounds.
You can see a diagram of the separate ground rod version in the link that GroundUrMast gave you:
Antenna basics
http://www.hdtvprimer.com/ANTENNAS/basics.html
scroll down to
The NEC requirement
In your case, the antenna mast is at the top of the hill. This would mean, for a strict interpretation of the NEC, a very long 6 gauge wire, which doesn't seem very practical. These days, copper is not cheap. A reel of 300 ft of 6 gauge bare copper grounding wire (solid or stranded) will cost you $200 to $300. Dish installers have a similar problem, which is why they often use coax with an attached 17 gauge copper coated wire to ground the dish structure and ignore the 6 gauge bonding wire requirement.
http://www.dbsinstall.com/diy/Grounding-2.asp
If you plan on doing the grounding work youself, be sure not to disconnect the grounding connection for the house ground even for a second when adding your grounding wires, and also the dish wires. Use split bolts that allow you to add your wires to the house ground. There is a device mentioned by GroundURMast called an Intersystem Bonding Termination that allows you to connect your grounds without disturbing the house ground because it has a lay-in connection for the house ground conductor. I saw it being used on a recent This Old House show:
http://www.erico.com/public/library/fep/LT1476.pdf
I find your intelligent questions about your installation almost over my head. I have a fairly good grasp of the theory, but I don't have much practical experience with an installation like yours that requires some custom solutions for your problems:
I don't know about the regulations in your area for an antenna installation. Some towns require an electrical inspector to give an OK for an installation; others don't seem to care. I would hesitate about asking your inspector about your installation until you find out what kind of person he is. Ask a local electrician about the inspector when he helps you with your ground connections to your electrical system. The dish guy would also know about your inspector and if any inspections are required. There is a device called an OTA/satellite diplexer that allows the same coax to be used for both signals. It usually allows DC power for the dish to get thru, but I don't think it will power your preamp.
http://www.hollandelectronics.com/ca...-Diplexers.pdf
A long run of RG6 coax has a signal attenuation of about 6 dB per 100 ft for UHF. RG11 is only a little better at 5 dB, and 1/2" 75 ohm hardline about 2.5 dB. The question is whether the reduced attenuation of the larger coax is worth the expense. The other consideration is how much the coax will reduce the voltage to the preamp, if you use one. Pete's chart for the RCA preamp shows the output voltage of the regulator, but it doesn't tell us how much the voltage can be reduced and still allow proper operation. In his earlier installation he used a separate voltage feed wire to the top of his tower and added a voltage regulator near the preamp. Calaveras used a custom power supply for his power injector that delivered enough voltage to his preamp on the upper end of his long coax.
Before you spend a lot of money, I suggest that you consult a senior level guru like Pete Higgins or Calaveras (they live in California) about your installation. Both of them have towers, long runs of coax, and have integrated FM into their antenna systems. You can see how they have solved their problems in the diagrams in the attachments. You can send them a PM; Pete Higgins often comes to this forum, and Calaveras is often found here:
The Official AVS Antenna and Related Hardware Topic
http://www.avsforum.com/forum/25-hdt...are-topic.html