It is unlawful for any person, firm or corporation to engage in the business of erecting or installing masts or towers for antennas or similar devices for receiving or transmitting radio frequency signals, or to erect or install such masts, towers or devices without first obtaining a license from the city – or to erect any exterior television or radio masts or towers or other like apparatus without first obtaining a permit therefor from the building inspector, except that masts, towers or devices twenty feet or under in height, and installations by licensed amateur radio operators for their own use, shall be excluded from the provisions of this section pertaining to the securing of a permit – or to erect, install, maintain or use any exterior television or radio mast or tower or other like device in violation of this chapter – provided, however, that nothing in this chapter contained shall apply to the installation of radio masts or towers or like apparatus in or upon vehicles. (Ord. 993 §1, 1953)