Roger - do you remember Dennis (Gentry I think the last name was) - His methods were similar I think - had to do with fluctuating patterns in the VHF band - here's a excerpt from a document about a radio astronomer I have on it:

According to Kushida's hypothesis, before an earthquake, electric charges accumulate on the Earth's surface due to the generation of numerous microcracks in magma.

The charge and discharge process of a capacitor formed with the Earth's surface and the ionosphere changes density of electric plasma in the ionosphere, and the phenomenon is observed by the FM receiver.

Indeed, it has been long known to scientists that some electromagnetic phenomena appear before an earthquake on the Earth's surface.

And then there's another article similar to that one here:
http://www2.gi.alaska.edu/ScienceForum/ASF5/542.html titled Do Earthquakes telegraph their punches?

Canie