Originally found this link on "The SWLing Post" blog....Remember tuning in on a old analog valve or transistorradio. I had a lot of fun trying this....it certainly gives the feel. Including english and russian number stations...
https://www.cdsshortwave.org/
I just discovered that the programming is changing. Different stories, different number stations and different sounds every day. So it is interesting to come back to this site once and a while...