"Any" signal is a pretty broad concept. It will detect signals in the range and freq. given in the datasheet. It will probably detect something with just a bit of wire sticking out, but it all depends on what you want to see. I've had a similar log. detector chip on a small board with a little dipole on for relative measurements, and that did pick up some signals, but depending on what it is, you may want to put a LNA in front of it.