Having a properly grounded outdoor antenna is crucial for optimal performance and safety. A good antenna ground protects against lightning strikes and static buildup, reduces interference, and allows your antenna to work at maximum efficiency. Installing a proper ground is not difficult, but does require following some key steps.
Choosing the Right Grounding Location
When deciding where to install your antenna ground, aim for the shortest possible grounding wire. The grounding wire should be as straight as possible, with no sharp bends or kinks. Some ideal grounding locations include:
- A metal cold water pipe less than 10 feet from your antenna. Cold water pipes provide excellent grounding.
- A metal grounding rod driven into the earth near your antenna. Ground rods should be at least 8 feet long and made of copper-clad steel.
- The metal frame of a building or tower close to your antenna.
- An existing electrical service ground near your antenna.
Avoid grounding to gas lines, plastic pipes, and telephone or electrical grounds used by other systems. Stick to a dedicated metal grounding point as close to your antenna as possible.
Selecting the Ground Wire
Use a heavy gauge bare copper grounding wire for your antenna. Solid copper wire is best, in a gauge size of 8 AWG or lower (meaning thicker wire). The ground wire should be able to handle the full force of an antenna strike without failing.
Some examples of good ground wire gauges:
- 6 AWG copper wire – Capable of handling 70 amps
- 8 AWG copper wire – Capable of handling 55 amps
- 10 AWG copper wire – Capable of handling 40 amps
Aim for 6 AWG or thicker if your antenna is 50 feet tall or higher. Go with 8 AWG or 10 AWG for shorter antennas. Avoid exceedingly long ground wires whenever possible, as the increased resistance will reduce effectiveness.
Connecting the Ground Rod
If using a standard ground rod, begin by driving it at least 8 feet into the earth, going deeper if your soil is sandy or dry. Use a sledgehammer or specialized driver tool designed for ground rod installation. Make sure the top of the rod is flush with or just below ground level.
Connect your ground wire securely to the rod by either:
- Using a heavy-duty ground rod clamp.
- Wrapping the wire around the rod and tightly clamping or brazing it.
Avoid simply tying or loosely attaching the wire, as you want a solid, permanent metal-to-metal connection.
Securing the Ground Wire
Run the ground wire in as straight a line as possible from your antenna support structure to the grounding point. Use insulated wire staples rated for direct burial every 3-4 feet to secure the wire against the side of your home, tower, or rooftop.
Bury any portion of the ground wire running through soil. Dig a 6 inch trench and cover the full run of underground wire. This protects against damage and tampering.
On a rooftop, securely attach the wire to the roof’s framework using weather-resistant cable ties every 3 feet. Run lightning arrestors along the cable when descending from the roof to prevent side flashes.
Keep the ground wire well clear of power lines, guy wires, and other antennas. Never run ground wires parallel to these as it can introduce interference.
Bonding the Ground to Your Antenna
At your antenna, securely bond the ground wire to the metal antenna mast or support structure. Use weather-resistant connections like:
- Appropriately sized copper lugs, washers, and nuts tightened firmly with a wrench
- Commercial grounding clamps suitable for the installation
- Silver-bearing solder for joining copper to copper
Join a wire from the antenna directly to the ground wire using one of the above methods. This bonds the two together electrically, shunting static and current into the earth safely. Take time making solid connections here, as poor bonding can render your ground ineffective.
Installing a Lightning Arrestor
Lightning arrestors provide an extra layer of protection for your equipment in the path between the antenna and ground. Install one just before the cable enters your home according to the manufacturer instructions.
Key tips when installing lightning arrestors:
- Position it as close to the antenna as possible for best effect.
- Securely attach it to a grounded metal surface like an antenna mast or building framework.
- Use heavy ground wire and short cable runs between the arrestor and antenna.
- Check that cables from the arrestor to equipment have solid metal-to-metal connections.
A quality arrestor properly integrated into your setup can safely divert thousands of volts from a lightning strike. This prevents voltage from reaching and damaging your equipment.
Grounding Coaxial Cable Shields
In addition to grounding the antenna itself, also ground the outer shielding of any coaxial cables that run from the antenna into your home.
To do this:
- Strip back a section of the coaxial cable’s outer jacket and braided shielding.
- Install a grounding block or appropriate sized cable clamp.
- Securely connect heavy ground wires between the now exposed shields and your grounding point.
Properly grounding coaxial shielding ensures static charges and other interference have a path to the ground before reaching your equipment. It also functions as a backup path in the event of arrestor failure.
Testing Antenna Ground Effectiveness
Once your antenna ground is complete, test it to ensure optimal performance:
- Use a multimeter to check for continuity between your antenna and the ground point. You want as close to 0 ohms resistance as possible.
- Connect an AM radio tuned between stations to your antenna lead-in and listen for noise with the ground wire unattached and attached. A proper ground should significantly reduce noise when connected.
- Have an electrician perform a soil resistance test using a specialized ground resistance meter. A reading of 25 ohms or less indicates a proper ground for a consumer antenna.
- Monitor your setup during thunderstorms. Properly grounded masts and arrestors should dissipate lightning strikes with no damage.
- Check your ground wire and connections once a year for corrosion and tightness. Refasten or replace degraded connections.
Installing a robust outdoor antenna ground takes some work, but pays off in the long run by keeping your equipment safe and operating optimally. Following the steps outlined here will help ensure you have an effective antenna ground in place.
Frequently Asked Questions About Installing an Outdoor Antenna Ground
What size ground wire should I use for my antenna?
For most consumer antennas, 8 AWG solid copper wire is recommended as a minimum. Go with thicker 6 AWG for larger antennas or installations at higher elevations. The ground wire must be thick enough to handle a direct lightning strike without failing.
Can I connect my antenna ground wire to my electrical service ground?
You can, provided your electrical ground meets standards for proper resistance and isolation from other systems. Using a dedicated grounding rod is ideal, however, as it isolates your antenna from any interference present on electrical grounds.
How deep should I bury the ground wire?
Bury any portions of the ground wire running through soil at least 6 inches under the surface. This protects against accidental damage from digging, lawn equipment, etc. Use wire rated for direct burial rather than standard copper wire.
Where should I install a lightning arrestor?
Install the arrestor as close to your antenna as possible – before the cable enters your home if mounted externally. This provides the most effective protection. Follow manufacturer instructions and connect the arrestor securely to your ground.
Can I ground multiple antennas to the same rod?
It is possible, though you may get interference between systems. Running separate grounds for each antenna keeps them well isolated and is recommended for optimal performance. Consider a larger shared grounding point for multiple antennas.
How do I ground the shielding on coaxial cable?
Use a coax grounding block or clamps to securely bond the cable shielding to your ground wires. Strip back the outer jacket and shielding, then clamp or solder ground wires to the exposed shielding. Keep cable lengths short.
Should I insulate my ground wire?
No, ground wires should remain bare copper to allow the wire to shunt current into the ground along its entire length. Use insulated wire staples rated for direct burial to secure it. Bury any underground portions in a shallow trench.
How can I improve a poor ground on sandy or dry soil?
Use ground enhancement materials like PowerGel around the ground rod to improve conductivity. Consider installing multiple ground rods spaced apart and wiring them together. Running longer rods 20-40 feet deep can also help reach moist soil.
How often should I check my antenna ground connections?
Inspect your grounds at least annually before storm season. Look for any loose, corroded, or damaged connections that could hamper performance. Refasten or replace degraded bonds and ground wires as needed to maintain a robust ground system.
Conclusion
Installing proper antenna grounding requires selecting an appropriate grounding point, running adequate ground wire, making solid bonds to your antenna, arrestor, and coaxial shielding, and testing effectiveness. While not complicated, each step must be done correctly to get a ground that protects your system and allows peak performance. Use the guidelines outlined here and you can feel confident your outdoor antenna has the grounding it needs for both safety and optimal reception.