11/27/2019
Steuben County
NY
APX4500 O2
Quick
Reference
Card
Tones Chart
Symptom
Possible Cause/Solution
Continuous low-
pitched tone
when pressing
the PTT button
The Time-Out Timer
has activated. May also
indicate an Invalid
Mode, or Talk
Prohibit/PTT Inhibit.
Short-Low
Pitched Tone
Radio Self Test Fail,
Reject, No ACK
Received. Time-Out
Timer Warning (4 sec.
before time out )
Long, Medium-
Pitched Tone
Volume Set
