Many of the most popular 4x4 off-road vehicles in use today are available as soft-top convertibles. This includes the Toyota FJ40, Suzuki Samurai and of course all flavors of the short wheelbase Jeep including the venerable CJs, Commandos and the Wrangler.

These rugged vehicles are designed for hard outdoor use and can usually be cleaned out with a hose after a hard days play. They also tend to be fairly compact and interior space is often at a premium.

The Radio Shack TRC-422

The Radio Shack model TRC-422 ("sports" model) CB radio would seem to be ideal for these vehicles. It is an affordable and compact 40 channel CB radio, easily mounted in a small vehicle, which is sealed with gaskets to provide a high degree of water resistance as well as protection from airborne particulates (like dust). While it only has a few controls (Channel, Volume & Squelch), they are simple, basic, and relatively easy to operate. All of the control knobs are sealed with o-rings to prevent moisture from entering the radio. The radio provides a full legal 4 watts of transmission power and picks up signals as well as most mid range CB radios that we have used. However, in actual use on our test vehicle (a Jeep Wrangler) we found that the radio did have a few shortcomings for our application.

An open top vehicle, particularly when driving down the freeway with off-road tires, is not a very quiet place. The radio's built in speaker, even at full volume with the radio mounted up on a roll bar, did not have enough output and was drowned out by road noise. Normally this would not be much of a problem as most radios have an external speaker jack and we could use an external amplified speaker located closer to the drivers head. Unfortunately, this radio does not have an external speaker jack (I could have installed something myself, but it would probably not be sealed and would compromise the weatherproofing of the radio). On the trail, without all the highway noise, this problem is not as severe and the radio has enough volume to make itself heard.

We also found that the channel selector knob was just too easy to move. While the rotary knob does have detents, they are not very positive, and when we picked up the microphone we would often brush our hand or the microphone cable up against the knob and inadvertently switch channels. This problem was further compounded by the fact that the red LED channel display is easily washed out and hard to read in full sun (when the top was down). Because of this, we would often not notice that we were off of the group channel until we had missed some significant traffic.

With its affordable price and its compact, weatherproof design, it seems that this radio would have been ideal for use in these open top, off-road vehicles. We found that, while it would make a fine radio in a closed vehicle, in our open top Jeep the radio fell a bit short of our high hopes in a couple of key areas.

• Your local Radio Shack store