The thing is, this stream, as well as a music stream from the same RasPi server, is active 24x7. And my echo is already connected to a bluetooth speaker (as a client to the echo). I'm not sure the echo can perform both as a receiver and transmitter at the same time (with bluetooth). But regardless, I am pretty sure this can be done by writing a skill for it, I'm just not there yet.
I know this seems a bit lazy anyway, but the radio and the Pi are located in my garage, and I can get to either stream easily from my pc or phone, but it would be nice just to tell Alexa to start broadcasting the scanner or music stream and have it active in whatever room (I have 3 dots) I am in.