From the experience and knowledge I've found out about, the bumper is a bad place for it. Every antenna uses the piece of metal it's attached to for the ground plane. The better the ground plane, the better the reception. My ground plane is my entire roof. A numper mounted one just uses the bumper. This is bad because it a) is much smaller = worse reception b) covered in plastic up top = worse reception and c) the antenna is mounted low, and askew. If you look back to one of Edzaar's links, you can see how that can negatively affect the antenna's signal. Basically anything that is around the antenna's lateral plane will disrupt it's field. My antenna was mounted right behind my light bar, and once I moved it back so it was as far away from roof racks and stuff, my reception got even better. Another reason you probably have not-so-good reception is the ****** spring. Anything that you put between the antenna and the other end of the coax cable (where it plugs in) will weaken your signal a little more. This includes springs, disconnects, etc. You were asking about tuning it: yes, you should tune it. n fact, everybody should tune every radio before the really use it for even mild functionality. Don't bother buying a 'tunable' radio or an antenna with a tunable tip. My friend has one, and the limitations of his tunable antenna prevent him from getting the right SWRs. How you want to tune the antenna is with an SWR tuning meter. All it is is a little box with a meter and two coax cable connections. One is where you plug in the antenna, and the other is where you plug in a short jumper coax that you then plug into the radio. You can buy one on Amazon with a jumper for like under $20. Let me know if you need more help once you get this stuff. Or Edzaar, haha, he knows more than I.
But still, I know more about CBs and how to make them work well than all the trucks you see driving around with a firestik mounted up all jammed between the cab and the bed and don't tune them -_- Putting them right behind the rear window on a pickup in the least functional place for it. Anyway, hope this helped. And if you need some real solid advice on your specific setup, hit up a local Radioshack and they normally have at least one employee who's an expert on CBs who can help you a lot. My guys saved my ass and helped me get a really good setup going on. I've got a cheap radio, and a cheap mag mount antenna, and I still get really clear reception up to San Jose, CA... which is almost 200 miles from where I live.
