An original analysis of thick tubular antenna is presented. Using the method of moments, Pocklington's integro-differential equation is solved for the z-directed current density. Both vertical and azimuthal segmentation is utilized. A novel and singularity-free representation of exact kernel is introduced. Circumferential change of the calculated current density is displayed when the antenna is excited by a z-polarized plane wave. The accuracy of admittance results are discussed by comparing calculated values with measured ones.