Be warned: The latest fw versions from r406 upwards use a different approach arranging the radio types. QGC 1.3 and lower versions don´t reflect that matter.
Upgrading to latest version of QGC is highly recommended!
You will need to manually change the radio types in the parameter list, transmit and save them for now.
Restart/reboot/repower the FC, refresh the parameters list to make sure they were stored correctly!
The above example shows the config of the internal Deltang receiver on the M4
To change externally attached radios use these values in the parameter list for "radio setup", store them and restart:
radio type is -1
radio setup is like 48 (sbus) und 64 (ppm)
internal deltang only = 7
ext. spektrum 11bit = 16
ext. spektrum 10bit = 32
ext. s.bus = 48
ext. ppm = 64