Sorry OBIO this is my oversight (laziness) - I just amended an existing aircraft.cfg' file and missed this setting.
What you are hearing is the NAV1 beacon. You can get rid of the morse by re-tuning Nav1 and the standby frequency.
A more permenant solution is to amend the aircraft.cfg file - [Radios] section thus:-
[Radios]
// Radio Type = availiable, standby frequency, has glide slope
Audio.1 = 0
Com.1 = 1, 1
Nav.1 = 0,0,0 // replacing 1, 1, 0
Adf.1 = 0
Transponder.1 = 1
Marker.1 = 0
Regards, Ted.