AFAIK several variations of the DIY 21-cm hydrogen line radio telescope project have existed throughout the years; the earliest one that I know of is documented in this poster from 2014. [0] It's certainly a fun, straightforward way to get a taste for radio astronomy, and I appreciate that the step-by-step guide and resources like Jupyter notebooks provided here make this project even more accessible.
I will say that gathering data that is unmistakably not noise, as well as meaningfully analyzing it, is difficult for would-be amateur radio astronomers (in my brief experience as a high school student aspiring to be one). I'd really like to see a version of this project that doesn't stop at just detection / ostensibly mapping Milky Way spectra, but given its limitations, I'm not sure if it's possible.
I will say that gathering data that is unmistakably not noise, as well as meaningfully analyzing it, is difficult for would-be amateur radio astronomers (in my brief experience as a high school student aspiring to be one). I'd really like to see a version of this project that doesn't stop at just detection / ostensibly mapping Milky Way spectra, but given its limitations, I'm not sure if it's possible.
[0] https://lweb.cfa.harvard.edu/~npatel/hornAntennaAASposterPDF...