Radio repairmen generally had repair manuals, published yearly, which covered multiple brands like Emerson, Crosley, RCA, Philco, Zenith, and Stromberg. They featured diagrams, instructions, and part listings. Other types of manuals include military instructions for working CB and Ham radios, socket layout manuals, and even a few handbooks for amateurs. Manuals are considered valuable to collectors who want to keep their antique and vintage radios in working condition.