Hustler 1C-56 102 inch CB whip on a SSM-3 pot-belly spring and a MFJ-945E mobile tuner. The whip is resonant at 27.2 MHz, but the tuner can take it up to 29 MHz no problem, as a full-size quarter wave whip is fairly broadband. See the SWR plot above from a RigExpert analyzer, which shows the...