Just like you car Stereo's AM/FM Bands, where the "AM" has more interference than the "FM", CB channels are transmitted & received using a similar "AM" type of transmission mode. Other two-way Radios like FRS, GMRS, Police scanners etc all receive in an "FM" mode. Again, with CB, just as switching to "AM" on your car stereo, you will notice more static than when on FM. Look for CB Radios that include a Noise Blanker ("NB") switch, which helps minimize some of the noise better than standard CB's that have no noise filters, or just an "ANL" switch (Automatic Noise Limiter).