Hi ladies and gents,
The original microphone works good, but I tested also the DTMF-microphone, which is available now.
It sounds really bad, and that wondered me, because a small electret-microphone is inside.
But after opening the mic, the reason was easealy located. The necessary DC-voltage, comes to the microphone via a small resistor. The value of this resistor is by far too low - replace it to a value near 10 Kohms.
Now the microphone is better than the original one and has all these options like DTMF and it´s backlighted !
The picture should help to locate the small resistor. The new one is a traditional one ( I had no SMD-resistor )
It looks bad, but it works fine....by the way the new microphone is very sensitive now...go down to values of 20 (original is 50 !) in the setup of the FT-817 specially in SSB.
Good luck !