User & Installation manual
VHF- Communication Transceiver
Doc.-Nr:
DE-3000-800100e
KRT2
Revision 12.2
Jan. 2016
49 / 61
5.9.4 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 join power current grounds with the microphone ground.
The cleanest GND is the case of the radio.
Put the battery-GND to the case and pin 1 and the microphone-GND to the
pin 9 only.
5.9.5 Connection support
In order to connect shields of all cables at a single point and to avoid
ground loops an adapter board as shown is recommended.
The adapter board is placed between the connector pin rows and soldered
to the BAT plus pins 8,15 and GND pins 1 and frame.
Pin 9 (microphone-GND) is provided on two pads for shielding.
Further information printed on the board serves to connect all cables to its
corresponding pins.
