"Japanese Slot Machine" 6445 USB 2125 UTC 18 NOV 2017

[Skipmuck]

First time I've heard this! Very distinctive almost musical sound. I looked it up online and apparently it's distinctive enough to have been dubbed the "Japanese Slot Machine"  Apparently it's actually a simplex system known as "Enigma Designation XSL" and is used by the Japanese Maritime Self-Defense Force. Always something interesting to find on the shortwave bands!

[MDK2]

I hear this frequently early mornings at 6250. It's not always on but it was yesterday morning.

[Josh]

You can attempt to "decode" slot machines (as well as other signals common to hf) with this nifty app;
http://www.saharlow.com/technology/sigmira/

[Token]

I hear this frequently early mornings at 6250. It's not always on but it was yesterday morning.

You may not always hear it, but I have never seen a time it was not on.  Anytime I have ever looked for it I could find it using Asian remotes.  And locally I hear it every morning, on multiple frequencies.

T!

[Looking-Glass]

The Slot Machine is also on 8.313MHz here as well as 6.445MHz. 

A fellow I chatted with on another DX page supplied the following a couple of years or so back:

Operated by Japanese Maritime Self Defence Force, located at Ichihara, Japan with QPSK at 1,500Bd to transmitter.

They have been around for quite awhile now.  I use them as an Asian propagation indicator.