User's Manual

Troubleshooting
RFI-148 & RFI-900 High Output Power Paging Transmitters User Manual Page 130 of 134
G.4 High Transmit Power
A high transmit power fault could indicate a hardware issue, however it is usually due to incorrect
configuration. The high transmit power fault will go active when the sensed transmit power exceeds the
transmit power upper cutoff. A high transmit power fault is usually seen in tandem with high PA current and
foldback faults.
If the transmit power setting has been increased without changing the sensor cutoff values then this is likely
the cause of the fault. See G.1 for troubleshooting sensor cutoffs. For information on sensor cutoffs see section
Appendix E.
G.5 High VSWR
The high VSWR fault goes active when there is too much power being reflected into the RF out connection.
When diagnosing a VSWR fault ensure the guidelines on human exposure to RF emissions are followed in
section 2.3.1. To diagnose a high VSWR fault:
• Ensure an antenna is attached to the RF out port.
• Ensure the paging transmitter is configured for the correct operating frequency and the correct channel
number is selected.
• Ensure the antenna is tuned to the operating frequency.
o Also ensure any in-line devices (such as a cavity filter) are tuned to the correct frequency.
• Ensure there are no open circuits in the cable run from the paging transmitter to the antenna.
• If possible, visually inspect the antenna for damage.
G.6 Disable Transmit
The disable transmit fault is a fault action automatically performed by the firmware due to other faults being
active. The disable transmit fault action is caused by critical faults in the paging transmitter to stop hardware
damage or transmitting off frequency. A list of faults that will cause disable transmit and how to troubleshoot
them follows.
G.6.1 High PA or Driver Temperature
The temperature on the PA module has exceeded the sensor cutoff values (80 °C by default). To troubleshoot
high PA temperature:
• Ensure the fans are configured to turn on at a reasonable temperature. The factory default is
recommended and has the fans turn on at 40 °C.
• Check the ambient air temperature where the paging transmitter is installed. When transmitting at 250
W with an ambient temperature of 60 °C, the paging transmitter is expected to reach 80 °C. Ensure
proper air circulation and/or air conditioning in the area the paging transmitter is installed.