User & Installation manual
VHF- Communication Transceiver
Doc.-Nr.:
DE-3000-800100e
KRT2, KRT2M, KRT2RC
Revision 13.0
Jul. 2016
55 / 67
6.8.5 Wiring for dynamic microphones
Special attention is required for the wiring for dynamic microphones.
Because of the required high gain any mistake on the ground wiring leads
to interferences and feed backs.
The basic rules are:
Never connect the power current grounds with the microphone
ground.
The cleanest GND is the case of the radio.
Connect the battery-GND to the case and pin 1 and the microphone-
GND to the pin 9 only (standard allocation).
6.8.6 Connection support
In order to get clean cable shields connections, and to avoid ground loops
an adapter board as shown is recommended.
Figure 16: KRT2 Connection support
The adapter board is placed between the connector pin rows and soldered
to GND pins 1 and frame.
Pin 9 (microphone-GND) has its dedicated connections for shielding.