
Using up/down key to select the code;
Press TALK button to confirm the desired code and go 
back to normal mode. 
Note: RT388 can only work together when the units are 
 tuned to the same channel and have the same 
 CTCSS code on that channel.
VOX for Hands-free
When VOX is activated, there is no 
need to press TALK button to talk.
Tap MENU button three times, then 
“VOX” and VOX sensitivity level
(OF,01,02,03) will be displayed on 
the screen. 
You can adjust VOX sensitivity level by pressing up/
down key.
Note: OF means VOX function is inactivated; 03 is the 
 highest sensitivity setting and 01 the lowest. 
 Therefore, level 03 is recommended when the 
 radio is used in quiet surroundings and 01 for 
 noisy environment.
Select Call Tone
To inform other radio users in your 
group that you want to talk or you 
have finished talking by transmitting 
a tone to their radios.
Press MENU button four times, then 
“CA” and call tone number (01, 02, 03, 04, 05, 06, 07, 
08, 09, 10) will blink on the screen;
Using up/down key to select the tone you prefer;
Press TALK button to confirm the desired tone and go 
back to normal mode. 
As to how to send the desired call tone to another party, 
please go and check “ Call another party” on Page.
Channel Scan
Convenient to detect channels with 
activities.
When button is tapped, the radio 
will automatically scan for channels 
with activities. The scanning will 
stop when channels with activities are found, and the 
radio will play what it detects on that channel. 
To continue the scan, just press button . 
Note: When a channel with activities is detected, you 
 can join the conversation and back away from the 
 scan by pressing TALK button.
Call Another Party
Press button to transmit a call tone to 
other radios in your group so that they 
can be prepared when you want to talk 
or you have finished talking. (See how 
to select call tone on Page) 
Note: Another party can only receive the call tone when 
 the following requirements are met at the same 
 time.
1.The receiving unit is on the same channel and shares 
 the same CTCSS code as the unit that sends the call 
 tone; 
2. The receiving unit is within the communication range.
Monitor
To receive weak signals from other radios in your group, 
all you need to do is press MON button. 
vox
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