WSPR signal by Louis Taber, CC BY-SA 4.0 With those limitations in mind, Joe Taylor (K1JT) began working on a digital mode in 2008 specifically for exploring propagation paths. The protocol was ...

You can actually get the job done for less than the cost of a fancy hamburger, thanks to [RPiks]’s pico-WSPR-tx and the Weak Signal Propagation Reporter Network (WSPR). WSPR is a digital ...