7
i.
Mode switch
Select the Digital voice mode [10101] or the Analog voice mode [~].
When the Analog voice mode [~] is selected, ordinary analog voice
communications will be made. In the receive mode, however, the ARD9900
will automatically detect the mode of the incoming signal and decode signals
accordingly. The LED indicates the respective operation mode.
j.
Microphone connector
Connect the supplied microphone to this connector.
Below are the pin assignments of the connector.
1. Speaker output
-- Monitor output signal is present at this pin.
2. BIAS
-- Power source for an electret condenser type of
microphone. 5V DC through 2.2K
Ω
resistor.
3. GND
-- Chassis ground
4. TX
-- Grounding this pin will enable the transmit
mode.
(Same operation as the TX switch on the front
panel.)
5. D/A
-- Grounding this pin will force the unit to the
digital voice communication mode. When this pin is
left open, the operation mode will be set by the mode
switch on the front panel.
6. MIC PTT
-- PTT (Push To Talk) input.
7. MIC GND
-- Microphone ground signal
8. MIC IN
-- Microphone signal input
Rear Panel
k. Communication Connector (mini DIN 8 pin) for PC (RS-232C)
Pin Number
Signal
Signal Direction
1
TX
ARD9900
PC
2
DTR
ARD9900
PC
3
DSR
ARD9900
PC
4
GND
GND
5
RX
ARD9900
PC
6
RTS
ARD9900
PC
7
CTS
ARD9900
PC
8
NC
No Connection
Shell
FG
Frame ground
SP
DC IN
AOR,LTD.
+
-
OUT
IN
RADIO
IN
OUT
VIDEO
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