my cb transmits very bad it is not understanderable most of the time, if I am not moving
or at least under 30 mph it can be understood Has any one had this problem and what did you do to fix it

 

Have you changed CB antennas? If you did, was the replacement antenna tuned with an SWR meter?

 

Get a new mic...

 

I have been around CB radios for some time so having said that the first thing is to make sure the antenna is “matched” to the radio. Any CB shop can do this for you, and if you can acquire an SWR meter you could do this yourself.
Most any trucker will tell you that some CB’s are tunable, which basically means that a radio man can tune your radio for peak Performance. They usually tune up the modulation in the radio and if you have listened to CB’s for awhile you can tell that some radios are louder than others.
If after that you find others can’t understand you, then I would suggest a different mic, such as a noise canceling mic.

 

I had the same problem on my 08 Ultra. Seem like when sitting it would work fine but going down the road, got a lot of static. As simple as it sounds, I took the tour pack liner out and found the CB cable unplugged (barely touching the connector) and the FM antenna coax nut off too. Plugged the cable back in and the nut back on the FM and works great now.

 

Find a good truck stop there is always a CB shop close by.