Originally Posted by Bluesky
The antenna on your bus might work for CB, or it might not. Antennae are tuned, so if it was not a CB antenna ymmv.
Not only does the antenna need to be tuned, it needs to be for the correct band. CB is on the 11M band, business radio is on the 1.9M (close to 2M but a 2M antenna will be out of tune).
You cannot use a CB antenna for HAM or with other bands - the SWA ratio will be out of sorts and cause poor transmission and burn out your transmitter.
Be careful of the coax cable too - you need to match the coax with the standards. Each type of coax has a difference resistance and capacitance. If you put a CB on coax tuned for 2M, you will not get optimal SWA and the aforementioned issues can occur.