SOME OF THE TONES YOU MAY HEAR: 
The APX 4000/6000 portable radios use various tones or sounds to keep you informed of how the radio is operating 
and if there is a problem.  Some you will hear everyday (such as the channel grant), and some you may never hear 
(such as the system busy tone). Many of these tones are accompanied by a message on the main display screen.  
TONE  DESCRIPTION 
Channel Grant / Talk Permit 
Quick chirping sound (dah dah dit) 
Your transmission can proceed and will be broadcast. You 
must wait until the channel grant sound is finished.  
Long, medium tone (boooooooonk) 
You can’t talk.  Someone may be using the talkgroup
wish to use.  Wait until they are finished.  This tone is not 
the same as system busy.  
Quick series of tones (like a fast telephone busy) 
on the tower are busy and there is no 
open pathway for communication.  Continue pressing the 
PTT for up to four seconds as the system has you “in line” 
to talk.    
Fast telephone ringing 
You are private calling another radio and awaiting their 
acceptance of the call.  
Two short, high-pitched beeps 
Battery is critically low.  Replace your battery. 
Four high-pitched beeps 
You have initiated an emergency alert/call. 
Alternating high and low pitched tones 
Someone else has initiated an emergency alert/call. 
Quick beep while you are transmitting 
You have transmitted for 55 seconds.  The system will time 
you out at 60 seconds.  
Long, medium tone 
System has timed you out.  Key your PTT to continue     
transmitting.   
Two short, high-pitched beeps 
You have received a private call. 
Four short, high-pitched beeps 
You have received a page.