This paper describes the design and implementation processes of a radio telescope suitable for the detection of the hydrogen line, proposing a receiver system based on Software Defined Radio (SDR). The design and fabrication of the antenna are presented, as well as the results of its characterization (electrical, radiation), both with simulations and measurements in an anechoic chamber. The functionality of the instrument is demonstrated by the satisfactory observations of the hydrogen line emitted by our Galaxy. This is an affordable project that allows the development and application of the skills of telecommunications students since it includes many of the fundamental aspects of electronics applied in this field.