Hi Arnaud.

I suggest reading two sections in the Logger32 v4 User Manual: chapter 22 covers ‘sound card digital modes’ in general, and chapter 55 covers the microHAM devices specifically.

From what you say, you appear to be able to control the radio PTT through the micro keyer II which means you are probably using the correct serial port, speed and commands for that. 

Your problem with the tones suggests something wrong with some part of the process of generating and passing audio to the radio for transmission.  You can check that process systematically by following the audio, just as if you were tracing a fault in a radio:

1. Is the micro keyer II generating audio tones as it should?  With headphones plugged into its audio output connector, can you hear the tones?  If not, there appears to be a problem right there, or further back/upstream in the process meaning how MMVARI is working and being commanded by Logger32, and you.
2. If the micro keyer II is generating the tones, there appears to be a problem further downstream – possibly loose connectors or broken cables to the radio, or something wrong in the radio itself (e.g. is it configured to accept audio input, or FSK?).

73 et bon chance

Gary  ZL2iFB