Maybe Kaliningrad in CIS36-50 (BEE or T600) mode idling. This mode is associated with the Russian Navy
There are a huge number of these frequencies, which is decodeable (altho we don't exactly know what it means) using Rivet. In any case, see this article from our wiki and you can download a zip file with over 400 such frequencies here
T600 is often on the freq mentioned, however the signal on the zipped audio file is from a smart meter the power company has installed on your or a nearby home. The same noise should be audible thru the hf bands and varies, wandering around a few kc as it does its thing. Dunno if its a spur of the device but they all sound pretty much the same, wether in the EU or North America.