Both Andras and Prof Yaffle thanks for clearing things up. I do have no idea about sound quality produced this way, but if I read your messages well it should be sufficient, and I'm not a high fidelity freak. FM is a bit troublesome, that's the reason to think of satellite.
I now understand the idea, with for the time being two questions left : If I run kodi on a pi, how does it receive signals from 'remote' on phone or tablet and second is the remote on such a device an app ?
I have no or little experience with smartphones. I still use one pc running openelec/kodi for which I build a 'home brew' lirc receiver for a remote. Openelec/kodi on my raspberry model2 is totally controlled by the tv remote through CEC. That's why i do not yet understand communication between kodi and mobile device.
I do like the idea of seperate user on tvh for radio, great idea.
I will keep my eyes open for an old android or ios phone or tablet. It also seems to be possible to run kodi on some linux-based satellite receivers. I will investigate that further, but i'm on my way. Thanks for helping me.