How to Use a Mobile CB Radio Antenna for a Base Antenna

Mobile CB antennas can be used as base antennas with an adequate metal surface on which to mount.

Mobile Citizens Band (CB) radio antennas are designed for maximum efficiency when used on the metal surface of a vehicle. All antennas require either a metal surface or wires buried in the ground to serve as what is termed in radio electronics a "ground plane." A mobile CB antenna may be used as a permanent base-station antenna if you are willing to procure a minimum 2-foot by 2-foot piece of flat metal on which to mount it.

Things You'll Need

• 2- by 2-foot flat metal surface
• Cement or wooden blocks
• Ladder
• Open-end wrench set
• Metal ground plane and U-bolt mounting hardware

Instructions

Near-Ground Installation

1. Stack cement or wooden blocks so that the mobile antenna will be a minimum of four feet above the surrounding average ground level.

2. Place any flat metal object on top of the bricks, centering so it doesn't have any large surfaces hanging over the edges of the bricks. This step, though simple, is important because wind can blow over the entire assembly if not resting properly on the bricks. Excellent metal object examples are: old metal microwave ovens, 50-gallon drum barrels (won't need bricks if you can procure one of these), or any other metal object that provides the minimum 2- by 2-foot metal surface.

3. Set the mobile CB antenna on the top of the metal surface, at the exact center. This will provide equal distance of metal at the base of the antenna, which becomes part of the radiating functionality of your antenna.

Mast Mount

1. Set up your ladder and climb to the top of your antenna mast, taking your antenna and wrenches with you during the climb.

2. Install an L-shaped mast ground-plane platform with U-bolts to your antenna mast. This hardware may be purchased from Comet Antennas, Rohn Towers, or any other commercial antenna supplier. To install, simply loosen the U-bolt nuts with an open-ended wrench and slide the U-bolts over the top of the mast, sliding the entire ground-plane bracket downward until one or two inches of mast pipe extend above the top-most U-bolt. Tighten the nuts firmly until they cannot be tightened any further.

3. Set the mobile antenna onto the portion of the ground plane bracket that is horizontal to the ground.

Tips & Warnings

• If your antenna base is a through-hole mount, use an appropriate drill and drill bit to drill a mounting hole sized for your given antenna and then finish mounting with your antenna's mounting hardware. If you will be using an L-shaped ground-plane bracket, be sure you purchase one with a through-hole center, where the center hole is the required size for your antenna.

• Stay away from antennas and their towers or masts during thunderstorms. A direct or nearby lightning strike can energize the mast or tower, risking electrocution and possibly death.

References

• Davis Net: Ground-Plane U-Bolt Mounting Hardware Instructions (PDF)
• Criterion Cellular: Ground Planes

Resources

• Read this Article in Portuguese