The most efficient CB radio truck antenna rig is a pair of 102-inch whips mounted on either side of the truck bed immediately behind the passenger compartment. These can be seen on larger off road vehicles, many emergency and rescue trucks and some military Humvees. On big rigs and most utility trucks a twin whip setup tends to be impractical for daily street or highway use. The answer for truckers is either a pair of mirror-mounted center-loaded antennas or for pickups a pair of truck-bed-mounted fiberglass continuous-loaded antennas.
Why Length is Important
CB radios broadcast and receive signal in the 27-meter band, which has a wavelength of about 36 feet from peak to peak. To operate with top efficiency an antenna needs to be either that length or some derivative length thereof. The optimal mobile CB antenna is exactly one quarter wavelength, or 102 inches. One 102-inch mobile whip antenna has a level of efficiency topped only by two 102-inch whips. The next best thing and one of the most popular truck rigs, as of this writing, is a pair of center-loaded 54-inch antennas mounted on either side of the truck bed or, with big rigs and semis, on both side mirrors. The 54-inch center-loaded antenna emulates the quarter wave of the 102-inch whip by wrapping an additional 48 inches of antenna wire in an insulated coil about ten inches up the antenna staff. Others use a tightly wrapped coil at the base (base-loaded), a wire coil running from top to bottom and covered by a fiberglass sheath (continuous-loaded) or a coil placed at the top (top-loaded) portion of the antenna.
For general all-weather, all-terrain use the fiberglass continuous-loaded CB antenna appears to be the most durable according to experts at Signal Engineering, Right Channel Radios, RadioShack and other electronics specialists. The center-loaded or “trucker” antenna come in a close second and the base-and top-loaded varieties are the least durable as well as the lowest in cost. Given that all CB radios are limited by the FCC to a maximum of 4 watts of output power, if your CB usage is confined to listening and talking without using any of the many other accessories that come with the more costly CB sets, your best CB investment is in a dual-truck antenna rig.
The Coaxial Connection
Next to the antenna, the most important component outside of your CB radio is the wire connecting the antenna to the unit. Using the correct gauge and strength of coax can mean a difference in broadcast efficiency of as much as 25 percent. Look for heavily insulated all-weather coaxial cable with stainless steel or weather coated metal connectors.
Finding the Right Mounting Hardware
CB antenna mounting hardware can be found at a number of locations both on the Internet and in bricks-and-mortar electronics shops. As with coaxial cable connectors, look for stainless steel or weather-coated metal antenna mounts. Generally center-loaded and continuous-loaded antennas are sold without cable or mounting hardware. However, some complete kits with antennas, cable and hardware remain on the market. One of the most complete outlets for hardware as well as CB radios, CB antennas and coaxial wire and fixtures is RadioShack. Many RadioShack personnel are CB operators themselves and are happy to share their opinions with you on all aspects of citizens-band radio form and function.
- Thinkstock Images/Comstock/Getty Images