"Detect galactic hydrogen using roof flashing, a paint-thinner can, and a software-defined radio", article by David Schneider, IEEE Spectrum Magazine,
September 2019.
The author estimates the project cost at around USD150 (AUD225).
Quote:
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Originally Posted by David Schneider, IEEE Spectrum, September 2019
At my instrument’s “first light,” I was able to detect the neutral hydrogen line with just a little squinting. After getting more familiar with the HDSDR software, I figured out how to time-average the signal and focus on the spectral plot, which I adjusted to display average power.
This plot distinctly showed a hydrogen “line” (really a fat bump) when I pointed my horn at the star Deneb, which is a convenient guide star in the constellation of Cygnus. Point at Cygnus and you’ll receive a strong signal from the local arm of the Milky Way very near the expected 1420.4-MHz frequency. Point it toward Cassiopeia, at a higher galactic longitude, and you’ll see the hydrogen-line signal shift to 1420.5 MHz—a subtle Doppler shift indicating that the material giving off these radio waves is speeding toward us in a relative sense. With some hunting, you may be able to discern two or more distinct signals at different frequencies coming from different spiral arms of the Milky Way.
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Article here :-
https://spectrum.ieee.org/geek-life/...adio-telescope
