Symptom(s)
APX Portable Talk permit tone sounds twice when PTT(Double Key)
Issue
Multiple people pressing PTT at a very close time to each other
Environment
Busy system and PTT Warning Timer set to 750ms
Resolution
Changing the PTT Warning timer to 1500ms resolved the issue.
This setting can be found under the Trunking System - Astro 25 - PTT Warning Time (ms).
The PTT retry warning timer default is 750ms. However the current recommended value is 1500ms and is highly recommended for busy systems.