Symptom(s)
1. APX portable and mobile radios are missing calls.
2. Radios are not scanning correctly after switching to a new system
Issue
Improper configuration of the radios can cause scan issues.
Possible configuration issues:
TDMA channels listed in the FDMA bandplan of a codeplug (Trunking System > Astro 25 Channel ID > Channel Type) will cause the radios to navigate to channels they are not able to communicate with.
FDMA-only devices will have limitations when a call starts TDMA only.
Bandplan channel spacing should be set appropriately for the system type.
Environment
APX radios with mixed FDMA only and TDMA capable devices.
Radio system with mixed FDMA and TDMA bandplans.
Resolution
TDMA-only channels should not be listed in the bandplan of a FDMA only radio.
To mitigate mixed TDMA and FDMA scanning, another FDMA radio should affiliate on the TDMA TG to allow the system to downgrade the TG from TDMA to FDMA. This will force talkgroups with mixed members to use the FDMA mode.
The TDMA band plan channel spacing should be checked and verified to the correct value (12.5 KHz instead of 6.25 KHz)