Check out this video about the 70's CB Craze from the History channel. [ame]http://www.youtube.com/watch?v=StFue1QBWyE[/ame]
When I was OTR here in Oregon~the shower me state, we used 17 for East~West traffic and 19 for North~South as I recall. Been off the road (commercially) for over ten years now so things may have changed.
I go back a while with CB radio. My first license had the call letters KEZ-6343. In those days, at least in New England, truckers used channel 10. My first radio was a Lafayette Telsat 23 with an Astatic D-104 mike. This was a little before the CB world went spastic and everyone started jumping on the bandwagon.
Channel 19 was "chosen" by truckers for various reasons during the mid-1970s. One reason for the choice may be as good as another depending on who you ask and what part of the North American continent you were from. Firstly, when CB radios only had 23 channels, channel 10 became convenient to truckers since the emergency channel 9 was just one click up. Then, in 1977 when 40 channel CBs came onto the market, presumably channel 19 became popular because not only did it rhyme with 9, but since channel 19 was in the center of the 40-channel band, the antenna's SWR (standing wave ratio) could be conveniently tuned, thereby enabling the lower limit channel 1 and upper limit channel 40 to have an optimum SWR rating. (study antenna theory for details). Lastly, channel 19 being on 27.185 MHz, the next adjacent frequency 27.195 MHz was (and is still) assigned to low-power remote control devices such as garage door openers, model cars and airplanes, etc. This eliminated any potential splatter onto channel from CBers who were prohibited from transmitting on 27.195 MHz. The original 23-channel CB radios had inferior circuitry to the later, more stable 40-channel PLL circuitry. Those older 23-channel rigs had relatively poor adjacent-channel rejection. Strong signals on the band would splatter across several channels. Base stations were plagued by neighbors transmitting closeby, and so on, causing arguments and worse. In later decades, channel 19 became a truly international trucker/mobile channel and is used in many overseas countries. Incidentally, in Australia where channel 9 is likewise the emergency channel, the truckers channel is one click down at channel 8. In 1977, Australia initiated an entirely new Citizens Band in the UHF range. No skip noise and access to repeaters on some designated channels making it a very popular tool for truckers and others alike. In North America, the original Class A Citizens Radio Service would have been ideal for truckers, however overuse and signal congestion around large cities eventually made it unusable and it was later re-branded to the currently-existing GMRS--General Mobile Radio Service--with its low power and limited range.
Before CB, drivers either did the "wind" or the "pat" out the window to opposite passing trucks.....The original trucker channel was 10, but then 9 was made the designated emergency channel, 10 was too close to 9.....So a decision was made to use 19....Start jabboring on 9 in those days and watch what happened....Of course the Canadian drivers needed their own channel and designated theirs as 12, still is today.....Today the cell phone zombies rule, I get a kick out of watching them roam around, totally oblivious of their surroundings....
