Hi Guido
I can only offer my findings for the same power output problem.? I found the driver IC in my QMX+, the 74ACT08D did not have sufficient output at the higher frequencies.? I found this with the oscilloscope but had to remove the BS170's in case they were loading the driver at the higher frequencies.? It proved that the voltage out of the driver decreased with increasing frequency.? I replaced the driver and the QMX+ operated correctly.
I hope this helps.
Regards
Greg
ZL4GW
