It describes the construction of an antenna that can be used to pick up radio signals from the sun and Jupiter and play them on an ordinary short-wave radio receiver (such as a travel radio set) at about 21 MHz.
This is his design for the radio antenna,


He also describes how he manually points the antenna at Jupiter or the sun and picks up readings from them like this...

This strikes me that it could make a particularly wonderful raspberry pi project. The hackability potential is great, starting with just feeding the audio from the radio receiver into a sound card but also the potential for making a directional rig as well as a starting stone for building more elaborate set ups.
I've been interested in the NASA radio Jove project for a while but have been put off by the prospect of having to install something like this on the roof.

Something like this is much more realistically achievable.