A while back I bought myself a Tecsun PL-880 for SWL, as well as for its excellent FM performance (I love listening to baseball--Go Detroit Tigers!). Alas, it sat unused for the last year or so, until the recent tension with North Korea got me thinking about shortwave again. So, out came the '880, and I started scanning the bands.
What I notice is that I get a very strong buzzing or "helicopter" sound on every SW frequency, oftentimes louder than the static between stations, and always louder and more pronounced than the stations themselves (regardless of station reception).
The noise is not present on FM or AM -- both bands are crystal clear and a joy to listen to.
I don't recall hearing anything like this when I used to toy around with my ham radio with wideband receive.
I was about to declare this a problem with the hardware, when I remembered I have an emergency radio with SW receive, a Kaito Voyager. It too has the same sound on SW.
Makes me wonder -- what kind of local interference could cause this sort of phenomena? I live just a couple of miles from a major airport; perhaps that's the issue? Is there any way to mitigate the problem?