"jm" wrote in message
...
Hi,

I need informations on old radio system based on galena stone.
Is there anyone on this newsgroup that is specialist in this or is there
anyone that can route me on another newsgroup more appropriate or any
community ?

Thanks for answers

I think you are speaking of galena crystals that were used in crystal radio
receivers.
The junction with the galena crystal rectified rf signals that were
amplitude modulated, producing
an audio output directly to headphones or an amplifier.
Ed