Dear Mitch and Mike,
Tks for your help. This is highly appreciated.
Mitch, yes, full-duplex is off.
Mike, I also can notice this kind-of echo with the RRC-control side not connected to the radio side. Thus, I can't see the connection with any parameter in the TS-2000. Anyway, the side tone volume is set to 0.
I will try to record an mp3 file for you to have a feeling of that.
I'm still investigating if this has a coincidence with another strange behavior I can also hear sometimes. It's a kind of double audio. A bit similar to an stereo audio where left and right had some delay one with the other. I'd say that the echoed dits only occur when this happens.
It's a bit puzzling because this doesn't always happen. It happens sometimes.
Let me investigate a bit further and I will let you know.
Tks & 73 from Daniel, EA3GEO