I am sorry to hear of your blown finals, Edouard. You did well to repair them, something that would be beyond the competence of most Q900 users.
Here I have the Q900 V4 and I do like using the FT8CN FT8 app. But before finding your message, I had been wondering if the finals were delicate in this radio. I wonder if you problem is an isolated one or common. My own FT8 operations have been only for short durations because I fear of the possible failure.?
If anyone has any other experiences to share about FT8 on the Q900, please let us know.?
73 de Erik EI4KF