HFU HF Underground

General Category => General Radio Discussion => Topic started by: ETM71 on December 29, 2010, 1424 UTC

Title: Question: What's that sound?
Post by: ETM71 on December 29, 2010, 1424 UTC

What is the machine gun/bubbly laser sound that I hear all over the bands? Was hearing it alot around 6950kHz last night. Quick "zapzapzapzapzap..." noises. Is is OTH radar? It would be great if there was a place to look up unknown (to yourself, at least) noises heard on the HF bands.

Title: Re: Question: What's that sound?
Post by: Seamus on December 29, 2010, 1704 UTC

If I am thinking of the sound you are describing, then I believe it is either OTH radar or ionosonde transmissions. 

The sweeps last for a few seconds each, jump around the band, and vary in speeds, right?  If you hear them strong and clear, you'll usually get three beeps just before the sweeping starts, right? 

Sometimes you'll hear just one speed, sometimes you'll get two or three, and occasionally you'll get what I think of as a "full diagnostic sweep" with every flavor from the fastest burr to the slowest "whoop-whoop" that they generate.

Title: Re: Question: What's that sound?
Post by: ETM71 on December 29, 2010, 1737 UTC

Here's one : http://www.4shared.com/account/audio/ntfH9iSi/unid_sound_laser2_6925usb_abt0.html