sometimes fiberglass or any antenna with a solder joint can fail at that solder joint and the antenna will never tune at it's intended frequency . is it a new antenna or old ? even new ones can be a lemon but it is rare . you may also not have a good ground connection for the ground side of the antenna . if you still have the 102 with the spring try it on the stud on tour mobile to see if you have a similar issue . if you do the issue is in the ground or install . if you don't something is up with the FG antenna . or .... if you have a antenna analyzer you can use that to find where the antenna will tune and if it's close to the cb band some additional tuning should help . if not then try another antenna AFTER tripple checking your install for good connection to RF ground on the vehicle and no shorts between ground and hot on the antenna mount .