what is this transmission?

[Se7en]

I occasionally listen to USCG freqs and was finally able to get a very short recording of this very odd noise it reminds me a lot like the same sound that a OLD fender amp with a spring (reverb inside) and if you turn the amp up and tap the side of the amp or kick it you can produce almost the same sound. just want to know if its Digital encrypt, or analog encrypt or another type of mode other than your standard AM FM....:laugh:

 

[W5LZ]

I don't know what it is, but it does sound 'digital' in nature.
- 'Doc

 

[Se7en]

I don't know what it is, but it does sound 'digital' in nature.
- 'Doc

Update here is a longer recording its a little distorted and a little bit different but here it is

 

[TonyV225]

That my friend would be digitsl signal you are hearing