In the meanwhile I found a solution :
nadine@nadine-Aspire-E1-531 ~ $ dmesg | grep dvb
[ 143.339447] dvb-usb: found a 'AVerMedia AVerTV Volar HD/PRO (A835)' in cold state, will try to load a firmware
[ 143.340923] dvb-usb: did not find the firmware file. (dvb-usb-af9035-02.fw) Please see linux/Documentation/dvb/ for more details on firmware-problems. (-2)
[ 143.340933] dvb_usb_af9035: probe of 2-1.2:1.0 failed with error -2
[ 143.340949] usbcore: registered new interface driver dvb_usb_af9035
I therefore got the missing file via :
wget
http://xgazza.altervista.org/Linux/DVB/ ... 9035-02.fwcopied it to /lib/firmware
sudo cp dvb-usb-af9035-02.fw /lib/firmware/dvb-usb-af9035-02.fw
then a reboot
and all was working !
Another solution which was proposed to me was :
additional installation out of the packetsource : linux-firmware-nonfree