I have been making lots of recordings recently on the Explorer E202 of natural radio signals finding mostly sferics but also the occasional (very exciting) whistler. This week I have taken E202 to Bletchley Park to see what electromagnetic signals I can pick up there. Plenty of hum mostly, the site is right by the train line and hums like one enormous generator. I have been trying to find increasingly more isolated spots around the perimeter in the hope of getting away from 50Hz and its overtones…

Inside blocks C and D the pigeons continue their performance.

photo by Rachael Marshall