There are a number of frequencies, where a certain type of signal can be heard. The characteristics is, that every occurrence takes about 2.5k bandwidth, and it is transmitted in a continuous way. Specific is as well, that it looks like a rather broad carrier, and sounds the same in AM or L/USB.
An audio example of it is at the following link (WAV, ca. 150k, ca. 5 sec): https://drive.google.com/file/d/0B4ecO4IudzvrOVRUX242MkQtbFU/view?usp=sharing
My question: What is it? As it is constantly transmitted I suspect it could be a weather radar. Can anyone state what it actually is?