Marcelo,
you're right, but in my case I've also a cable that connects the rig to the amp, that is :
miniDin 8                     Amp
Pin4 (MKE)  ----------  Relay 
Pin2 (COM) ----------  GND
So Pin 2 goes to GND at the amp side, that's why I used the same connection.
I made other QSO's in the meanwhile and I have to mark the "Inv FSK" in EXTFSK 1.05 in order to be copied correctly. (see my previous post)
( ... yes, I checked the "FSK keying polarity" (Menu 42) which is set to "OFF/Normal"  

 )
All in all, Remoterig are unbeatable Black Boxes.  SSB, CW, FSK ,CAT without computer , reliable and unmatched !
Thanks Jan , you know how to make Hams happy ...   

73 
Gianni IN3ASW