User's Manual

Troubleshooting
RFI-148 & RFI-900 High Output Power Paging Transmitters User Manual Page 131 of 134
• Ensure the fans are working. Check for blockages of the fan intake and exhaust.
G.6.2 High Reverse Power or Reverse Power Foldback
A high reverse power fault indicates a hardware failure of the circulator inside the paging transmitter. Failure
of the circulator can cause RF spectrum splatter, so transmit is disabled. Return the unit to STI Engineering
for repair.
G.6.3 Exciter Out-of-Lock
An exciter out-of-lock fault indicates that the channel frequencies can no longer be generated. There are two
possible causes of an exciter out-of-lock:
• If an external reference is in use: the external reference frequency has drifted too far from the
configured reference frequency. Check the accuracy of the external reference.
• A critical hardware failure in the paging transmitter. Return the unit to STI Engineering for repair.
G.6.4 Transmit Timeout
The transmit timeout fault goes active when the unit has been transmitting for longer than the transmit timeout
duration. The transmit timeout fault can either be disabled, or the timeout can be increased.
G.7 Unit Won’t Transmit
There could be several causes for the paging transmitting not transmitting, each is explained below.
G.7.1 PTT Override
The paging transmitter PTT override can disable the transmitter from transmitting. The status of PTT override
is displayed in the PTT Override Status field under the radio settings:
• Enabled: Transmitting is enabled.
• DISABLED:User: Transmitting is disabled because the user-configurable option PTT Override is set
to disable transmit. To enable transmit again, set PTT override to enable transmit.
• DISABLED:Fault: Transmitting is disabled because the disable transmit fault action is active. See
section G.6 for troubleshooting a disable transmit fault action.
• DISABLED:Listening: Transmitting is disabled because the isolator mode is set for listening. To
enable transmitting again, the isolator mode must be set for transmitting.
• DISABLED:Loading Config: Transmitting is disabled while Cruise Control is loading a configuration
file.