The reason I say we should look for low frequencies is that they are the easiest to handle for power distribution. As I said 50 and 60 Hz are the commonest frequencies we use. So, since we are using extremely large amounts of power which is distributed at those frequencies then the Earth must be radiating them. I assume that other civilizations will also go for such low frequency transmission systems, so they will also be radiating in that range. I would actually plan such a search for a range of possibly 20 to 3000 Hz, since it is unlikely that they would choose the same frequencies that we did.
Of course detecting these low frequencies is going to be a problem. Building antennae and receivers to catch them will be tricky, and there will be a huge amount of noise from our own radiation.
As far as why I say 50/60 Hz well, while more of the world may be using 50 Hz the USA uses a large part of the Earths energy, and therefore will supply a large part of the Earths low frequency radiation.
Bill Gill
