If you build a coax balun, the output will be 75Ω. Therefor a preamp would need to be specified with a 75Ω input.
Here's my recent response to a similar grounding question:
Quote:
I do live in a very active area of lightning, though, and have lost televisions (cable, no antenna), phones, and even computers to lightning in the past. Are there good ways to protect my television from lightning when using an outdoor antenna?
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Grounding the mast and coax shield are prudent and relatively inexpensive steps that limit the buildup of static-electricity which can damage the tuner. When done correctly, grounding can also reduce the risk caused by a nearby lighting strike.
http://forum.tvfool.com/showthread.php?t=901
Grounding in a basic system is a two step process:
1) Connect a #10 gauge copper wire to the antenna mast. A bronze ground clamp such as the Halex #36020 is well suited for this application. Run the wire directly to the electrical service ground. Avoid sharp bends in the wire. (Often you can use a
'split-bolt' electrical connector to clamp the #10 wire to the existing ground wire close to the ground rod outside the building. If possible, avoid running the new ground wire inside the building, energy from static or electrical storms is best directed to ground before it has any path into the building. The wire can be bare or insulated, your choice.)
2) Run the coax from the antenna to a location close to the electrical service ground. Install a
ground block and with another peice of #10 wire, connect it to the electrical service ground at the same point you connected the mast ground.
I don't recommend short-cuts such as driving a new ground rod that is not connected to the existing electrical service ground. An isolated ground rod often has a high resistance that provides very limited ground connection. The goal is to connect to the same ground system that protects the rest of the home.
Surge protectors located inside outlet strips at the TV, computer or similar devises are worth consideration. A surge protector with a high joule rating is able to absorb more fault energy than a unit with a lower joule rating. Some surge protection units include phone jacks and F-connectors to enable protection of a phone line, coax cable and the power cable(s). However,
in the case of an outdoor mounted antenna, this type of protection should not be considered a 'first-line of defense'.