UNID pulse noises, 50 kHz wide, 20M & 40M ham bands, 7/29 2120 UTC~

[BoomboxDX]

Recently there was a bizarre QRM phenomenon that hit the 20M and 40M ham bands, a constant pulse/beep heard nationwide in the US. The signals were around 50 kHz wide.

I tuned into it around 2119 UTC and thereafter, and it was about 50 kHz wide, and seemed strongest around 14133 kHz. Other people heard it in the same frequency range -- 14125-14175, and a similar range in the 40 Meter band (I didn't hear it down there, I didn't tune the 40M band that day).

I'm in WA, and I heard it, hams in MS, WI, PA, NC, TX, MN and other places also heard it. I have a recording, but this guy on the Amateur Radio Subreddit has a recording with a waterfall off his ICOM 7300, which probably is a better portrayal of what a lot of guys heard across the country.

No one seems to have a clue what this signal was. Being that it was heard all over the US, it wasn't RFI.

Here's a link to the discussion. I'm posting it here because it seems pertinent to HFU's interests in curiosities, and also maybe some experts here can help determine what exactly this pulse noise was.

Here's a link to the discussion thread. Any ideas, anyone?

https://www.reddit.com/r/amateurradio/comments/1efrjdz/theories_on_rhythmic_interference_heard_across/