You'll notice than when many folks talk about their radios they mention that they have all the "Upper's" and "Lower's" installed. What they're referring to are the "Freeband" frequencies, or those channels below and above the legal 40. From the beginning of CB time operators have found ways to extend the capabilities of their radios giving them private frequencies to talk on.
In the early days, when radios used a transmit and receive "rock", or crystal to operate someone found out that if you switched them around you would be on a frequency that wasn't on the 23channel bandplan. Suddenly - a light came on inside their head, and then a thought: "Hey, I've got my own special channel now........"
With 23ch synthesized units wire snips were placed inside the radio case and with one snip, channels 22a and 22b were installed! Later, PLL circuitry came about and lans were cut, and wires run to enable other frequencies hidden within the EPROM.
Today, despite Uncle Charlie's attempts the Freeband lives on. While most of the activity occurs above channel 40, you'll find some AM action below channel 1 as well. But many of us like to listen as much as talk and in that case, there are no illegalities involved! THe FCC has been coming down on Freebanders all year long. In the Houston area, several Ham operators were sited for operating on 27.535 and 27.370. I've heard from other areas which have reported similar busts, although not necesarily rogue Ham operators. It pretty safe to say that if you keep your power low and talk within the 40 channel spectrum, you have little to worry about.
|26.285 USB||Worldwide Monitor Frequency|
|26.555 USB||East Europe / North America|
|26.720 LSB||Australia and New Zealand|
|26.840 LSB||Worldwide Monitor Frequency|
|26.985 USB||Unofficial Marine Channel|
|27.275 USB||South Africa|
|27.295 USB||South America|
|27.345 LSB||Portugal, Azores, Brazil, Madeira|
|THIS LIST PROVIDED BY Tim 2-IR-082 [Texas USA]|
|27.355 USB/LSB||Pacific and Australia|
|27.385 USB||North America|
|27.420 USB||Pacific and Africa|
|27.440 USB||Pacific and Africa|
|27.455 USB||Worldwide Monitor Frequency|
|27.460 USB||Pacific and Africa|
|27.470 USB||Pacific and Africa|
|27.515 LSB||South and North America|
|27.555 USB||Worldwide Monitor Frequency|