Did you know that Jupiter is sometimes a major source of decametric radio emission? There's a network of amateur radio astronomers monitoring Jupiter through the NASA RadioJove project. The band around 20MHz is quite a good region to observe decametric Jovian emission, which is why the Jove kits are designed to work at this frequency.
Scientists have theories for predicting the best times to detect Jovian decametric emission. There's a few sweet-spots on Jupiter for radio emission, poetically dubbed A, B, C and D. You are more likely to detect emission when one of these regions is properly aligned with the Earth, especially if moon Io is at a nearby longitude at the time. However this is largely just a statistical thing and sometimes there is no emission even if the alignment is perfect and at other times emission is detected when it would not be expected. The physics is quite interesting, Hannes Mayer gives quite a nice intro on his website.
There are normally two kinds of bursts that can be heard. The S (short) bursts sounds like hail on the roof or cackle like a fluro light turning on. L (long) bursts sounds more like waves on the beach. Here and here are a few of my best Jupiter audio recordings so far.
The two graphs below show prime examples of our 20MHz interferometer data for Jupiter. The top panels show the auto-correlation data for each Jove receiver, you can see that Jupiter is a very bursty source. For these long-duration storms it is easy to see the astrononomical fringe pattern in the bottom panels, proving that the emission is coming from an astronomical object - Jupiter in this case!