I have been gathering parts for a CB radio and it seems I am now finished. Before I mount it on my overhead rack, I decided to test it. At first, I was not be able to get any sound from the radio. I figure it was a ground issue so I took some sand paper to the CB antenna mount and now I can hear a faint static noise if I adjust the squelch. My problem now is that either I am not broadcasting a signal or I can't hear anyone. I got an antenna from an 18wheeler. I have a full size Uniden CB radio and I tried to pop the cap off the antenna but it does not come off. I suppose it's not tunable. I know the radio works because it works on my little tractor trailer. I assume I am still having a ground issue? I read the instructions for the CB antenna stud so it is on properly. What could be my problem?