Building your own CB antenna is more fun and useful than commercial antennas. If you have some thick copper wire and cut 2 pieces 17 foot(1/2 wave) connected in center on plexiglass with a coax center connected to one side shield to other and atleast 18 feet of coax to radio. You'll find Swr to read at 1.3:1 to less than 2.1:1 all around the band. Now you're on the air an ready for some local talking an some Dx contacts around the world..Remember formula 234/Frequency equals Length.(1/4 wave) It comes to 8.67 feet but for Inverted wire antennas you take off 5%. It could be 8.5 ft(102 inches). Either 1/4 wave or the longer 1/2 wave will do the trick to get suitable 1.3 swr. Try to build your own. Verticals are simply 103 inches 8.6 ft for 1/4 or 17.25 ft for 1/2 wave. The 1/2 or 5/8 wave doesnt need ground planes as short antennas will.The 5/8 wave may be 21.5 feet.