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: