User & Installation manual
VHF- Communication Transceiver
Doc.-Nr:
DE-3000-800100e
KRT2
Revision 12.2
Jan. 2016
51 / 61
5.11 Microphone general
The correct setting of the MIC and VOX values is of great importance for
the Intercom system (see 3.4.3. VOX Intercom Voice Trigger Level and
3.4.11. MIC Setup).
The VOX intercom voice trigger level must be set to such a value that the
intercom system is activated when speaking at a normal voice level into
the microphone. It should be set so that it is not triggered by normal cockpit
noise.
If there is extreme cockpit noise or there are uncompensated microphones
VOX should be activated with VOX=01 permanently and enable/disable by
a manual intercom switch.
The manual intercom operation is possible with one or two separate,
parallel connected, optional intercom switches. These switches are not the
PTT switches. The intercom switches connect pin12 (intercom) with GND
(pin1).
The intercom-deactivation will be indicated with “e” if pin12 is not on GND.
Communication with the VOX system requires pin 12 to be connected to
GND by means of one or two intercom switches.
The KRT2 unit transmits only when a PTT switch is pressed.
Cockpit noise suppression is only possible with differential microphones
used in modern headsets. Normal Electret microphones are not suitable.
