Nautel NV5, Troubleshooting Manual

Page: 26 / 228

NV5/NV3.5 Troubleshooting Manual Responding to alarms
Page 1-18 Issue 3.2 2014-12-10
Exciter A/B: PA Over
Temperature This alarm occurs if the temperature sensed within the exciter’s RF
power stage exceeds 70°C (158°F). The exciter’s RF output is
reduced to 0 W. Check the exciter fan’s air path.
Exciter A/B: PA Volts
Fail This alarm indicates the second-stage amplifier’s PA voltage is
outside its acceptable range of 40.5 to 49.5 V. Check the exciter’s
power supply (U3).
Exciter A/B: Pilot
Unsync This alarm occurs if there is no synchronization between the 10 MHz
and 1PPS signals. It may indicate that the GPS receiver is not
detecting a signal. Check the GPS receiver and antenna.
Exciter A/B: PLL
Unlock This alarm indicates that the exciter’s master clock is not locked
Possible causes are an out-of-range 10 MHz input or a hardware
failure on the NVE exciter PWB (A1).
Exciter A/B: Primary
Digital SRC Unlock This alarm indicate that no valid AES/EBU or SPDIF stream data is
being detected on the selected AES/EBU. Check cable connections
and verify the primary input assignments are set correctly in the
Hardware Configuration page of the AUI.
Exciter A/B: SCA 1
(or 2) Low This alarm indicates the SCA 1 or 2 input level is too low (default
threshold is 22.5 dB below full scale) or is not applied.
Exciter A/B:
Secondary Digital
SRC Unlock This alarm indicate that no valid AES/EBU or SPDIF stream data is
being detected on the selected AES/EBU. Check cable connections
and verify the primary input assignments are set correctly in the
Hardware Configuration page of the AUI.
Exciter A/B: SWR
Shutback This alarm occurs if the exciter’s peak reflected power exceeds 30 W
due to a transient SWR condition. The exciter’s RF output is
temporarily reduced to 0 W. Typically caused by a severe mismatch
(open or short circuit) at the exciter’s RF output. Check the RF load at
the exciter’s output.
Exciter A/B:
Unsigned DSP Image This alarm indicates that the exciter is operating with ‘unsigned code’,
but is otherwise operational. This alarm may only be displayed if the
transmitter is operating with a ‘beta’ version of factory software.
Exciter A/B:
Unsigned FPGA
Image This alarm indicates that the exciter is operating with ‘unsigned code’,
but is otherwise operational. This alarm may only be displayed if the
transmitter is operating with a ‘beta’ version of factory software.
Alarm (with Prefix) Description and Troubleshooting Action