13
OPTIONS
13-3
The transceiver has a VOX function, which allows 
hands-free operation.
An optional HS-94, HS-95 or HS-97 headset and the 
VS-4LA ptt switch cable or OPC-2004LA adapter 
cable are also required for operation.
What is VOX?
The VOX (voice operated transmission) function 
starts transmission when you speak into the 
microphone, without pushing [PTT], and then 
automatically returns to reception when you stop 
speaking.
 D Optional unit connection
1.  Hold down [ ] for 1 second to turn OFF the 
power.
2.  Remove the jack cover. (p. 1-3)
3.  Connect the optional HS-94, HS-95 or HS-97 and 
VS-4LA or OPC-2004LA.
CAUTION: DO NOT use the transceiver without 
the connector cover or the optional microphone 
attached. The transceiver meets IP54 requirements 
for dust protection and splash resistance only when 
the connector cover or the optional microphone is 
attached.
Displayed
Push , and then push .
 D Turning the VOX function ON or OFF
1.  Connect an optional headset and plug adapter 
cable to the transceiver, and then turn ON the 
power.
2.  Push [FUNC], and then push [VOX] to turn the 
VOX function ON or OFF.
 • “VOX” is displayed when the VOX function is ON.
NOTE:
 • When using the VOX function, adjust the 
microphone gain and the VOX-related settings 
(p. 13-4) to suit your operating environment 
(including your headset performance).
 • Set the microphone gain before setting the VOX 
gain in the Set mode. (p. 9-3)  
We recommend setting the microphone gain to 3.
 • When ‘TX permission’ is set to “OFF” in the Set 
mode (p. 9-3), you cannot transmit using the 
VOX function.
[ ]
(Turn OFF)
OPC-2004LA
HS-94
1
3
2
VOX function