  We present the Completely Hackable Amateur Radio Telescope (CHART), a project
that provides hands-on radio instrumentation and design experience to
undergraduates while bringing accessible radio astronomy experiments to high
school students and teachers. Here we describe a system which can detect 21-cm
emission from the Milky Way which is optimized for cost and simplicity of
construction. Software, documentation, and tutorials are all completely open
source to improve the user experience and facilitate community involvement. We
demonstrate the design with several observations which we compare with
state-of-the-art surveys. The system is shown to detect galactic 21-cm emission
in both rural and urban settings.
