Hi Ian, since a feww minutes before you write the mail I got a sound. The reason is I switch the gqrx Mode to WFM Mono and now it works.Nevertheless I want to install Pulse Audio Volume Control.
Many thanks for your help. I was already on despair, some days ago I made some tests with raspberry Pi as Server with the USB stick and Ubuntu Notebook as gqrx client and it worked right the first time.
Today I did the same without Raspberry, only Ubuntu Notbook and gqrx but I deleted my old settings.
Have a nice Sunday
Claus