Citizen Band (CB) radios have long been the universally-accepted mechanism for voice communications between drivers of vehicles. Despite the introduction of newer technologies such as cell phones and 2-way FRS and GSRM radios, CBs continue to reign supreme for automotive communications. The wide existing user base, established emergency channels, and ability to work where cell towers don't exist make them ideal for offroad vehicles. This page describes the details of installing a CB radio into my Hummer H3.
Before purchasing a CB radio, you must first consider the radios that are available, the feature set that you want, and where the radio will be mounted. While choosing my CB radio, I broke the different models into three categories.
A hand-held CB is portable and does not need to be installed. It may work sufficiently between vehicles within a small caravan. But, without a large external antenna, a hand-held CB probably would not have sufficient power to call for help if an emergency should occur. I did not consider any purely hand-held radios, but some of the more common ones are shown below.
Hybrid units have unique features that make them a bit easier to install in a vehicle where there is little room under the dash.
Most of the CB manufacturers offer small radio models. These units are very narrow -- only about 4 inches -- and could probably be mounted by the drivers right knee, just below and to the right of the steering wheel. But, these radios are typically low in features compared to larger units (and the two hybrids above, for that matter). For example, they do not contain weather radio, etc. A few of these small models are listed below.
If you don't mind mounting a CB radio on top of the dash, from the head liner, or in place of the factory radio, you can consider full size units. Since the OnStar and hands-free phone system are routed through the factory radio, I really did not want to mess with it. Also, I am tall, so mounting it from the headliner above the rear-view mirror is not a good option because it obstructs my vision. So, I decided to mount my CB radio on top of the dash. If you decide to replace the factory radio, I have heard that the Metra 99-3304 dash kit and PAC-Audio OS-2 and CM1 and wiring kits are quite useful on Hummer H3 vehicles.
After looking at many different models of CB radios, I finally decided upon a Cobra 18 WX ST II. I chose this radio because it seemed to have a nice feature set, and was inexpensive. I really liked the weather radio and dual tracking features. Additionally, since I was planning on mounting it on top of the dash, the forward-firing speaker and black chassis were definitely a plus.
Choosing the type and location of the antenna is important. Ideally, the antenna would be 102" long and mounted in the center of the roof. As you can imagine, that is not very practical for an offroad vehicle. Other options must be considered.
A CB antenna requires a good ground plane for proper transmission. For mobile CB radios, the vehicle itself acts as the ground plane. The signal travels best from the antenna in the direction of the ground plane. If the antenna is in the middle of the ground plane, the signal travels well in all directions. If it is on a corner, it travels best in a pie-shaped wedged.
This page is still under construction.