[en] The paper presents the results obtained from the study of a radiofrequency (RF) oscillator developed for use in an RF ion source, for the development of a low energy charged particle accelerator. An investigation was made on the main factors attributing to the operating frequency of the oscillator. Four different RF coils are constructed using a copper tube for studying the different operating frequencies. The RF output power was measured using a modified form of the photometric method. The variation of RF power with operating frequency are discussed. (paper)