Ground Block: Help with Your Outdoor Antenna


Lightning strikes cause transient electrical charges leading to millions of dollars in equipment and property damage each year. Satellite dishes and the TV system are especially vulnerable. Installing a ground block is key to preventing lightning damage by tying the TV system, cable, and dish into the ground circuit. 

Grounding is a process through which you connect the metal items on your home’s exterior to the ground (dirt, soil, earth, etc.). It is not always clear how you should ground your antenna. This guide will get you moving in the right direction.

Table of Contents

1. What is a Ground Block?

A ground block is a brass-made conductive transfer device. We often use it to facilitate the effective grounding of coaxial cables that run from external antennas and satellite dishes. The ground connection is a critical protective measure that helps prevent damage to television sets and satellite dishes as a result of lightning strikes and accumulated static electric charge.

The ground block consists of mounting lugs, ground wire connection points, and at least one built-in dual coaxial fitting. It consolidates the ground elements of the television set, dish assembly, dish cable, and transfer cable into one properly grounded unit. The dual coaxial fitting ensures you can run a second coaxial transfer cable to the TV set without signal loss. 

2. How do I Ground my Outdoor Antenna?

How do I Ground my Outdoor Antenna?

Grounding your outdoor antenna is something you can do on your own, even if you do not have a background in electricity, electronics, or telecommunication. As a precaution, you should ground your antenna twice. That is, the antenna itself and the mast as well. 

The National Electric Code (NEC) Article 810 is the most widely used standard for grounding. To ground your outdoor antenna, you will need:

  • A coaxial ground (or grounding) block
  • Two copper grounding wires
  • A house-ground clamp
  • A mast ground clamp

So how do you do it?

Locate Your House Service Ground Wire

Ground Block--Locate Your House Service Ground Wire

You ground an outdoor antenna through the house service ground wire. The house service ground would usually be located outside the house near the electrical panel or where the power service connects to your house. It is a thick copper wire connected to a grounding plate or ground rod (grounding electrode).

Connect the Copper Grounding Wire to the House Ground

There may be a ground clamp on the house service ground. Use this clamp to connect the house service ground to the copper grounding wire coming from the antenna. The copper wire should be at least a tenth of an inch in diameter (or 10 American Wire Gauge). Make sure the wire is solid copper as opposed to stranded wire. The stranded wire gets brittle fast and may eventually break.

If there is no ground clamp already, you will have to buy one. When shopping for the clamp, make sure it is of the appropriate size, depending on the size of the house service ground wire. The house service ground should be at least a quarter of an inch in diameter (or 2 American Wire Gauge).

Try to keep the copper grounding wire short and avoid making sharp twists and turns. In case you have to bend the wire, make the turn as gradual as possible. Lightning does not like bends, and you would not want a lightning strike to discharge into your home because it ran into an abrupt turn on the wire.

Connect the Antenna to Ground

Next, link the outdoor antenna to the ground by connecting it to the other end of the copper grounding wire you installed in the previous section. You do this by connecting your copper grounding wire to the coaxial ground block.

The ground block will have dual female coaxial connectors as well as a single slot for connecting the copper grounding wire. One end of the coaxial connector receives the coaxial cable from the outdoor antenna, while the other end has a cable going inside the home to the television or set-top box. 

The grounding block should be on the exterior of the house but ideally sheltered from the rain. Nevertheless, make sure the grounding block is horizontal to prevent water from seeping into the connection. As an additional safeguard, waterproof the connection using appropriate grease.

Once done with connecting the antenna to the ground block, flip through your television channels to confirm there has been no disruption. As long as the connection was correct, there should be little to no noise added

Ground the Antenna Mast

You do not have to ground the mast, but it is good if you do. It is after all a large piece of metal. Use a mast ground clamp to connect an 8 or 10 American Wire Gauge copper grounding wire to the mast. In case the mast is rusty or has some paint or other coating on it, scrape it in the place where you are going to fix the clamp. The idea is to ensure direct metal-to-metal contact. 

Next, run the opposite end of the copper grounding wire to the house service ground. You may need to buy a second ground clamp to connect it to the house ground.


Ground Block

That’s it! You have finally grounded your antenna. You have better protected your electrical systems from lightning strikes, static electric charge, and other forms of indirect electric energy. 

Remember that the objective of grounding is safety. Therefore, if you are not confident in your ability to do it, hire an electrician or antenna professional. It will cost you, but the benefits mean this cost is a fairly small price to pay. Any question? Contact us now.