First Start out with a Cobra 29, make sure you have a wilson 2000 you will have to have the antenna checked by a professional or someone who really knows how to check the SWR ( Stand Wave Radio) it is very confusing however, I had to really learn the proper channels of sWR, make sure your SWR are down to the lowest points such as 1.5 or lower that will give you the best SWR possible...check with a Radio shop...