Nautel XR6, Troubleshooting Manual, Page: 44 / 291

XR6/XR3 Troubleshooting Manual Responding to alarms
Page 1-24 Issue 3.0 2009-07-15
Troubleshooting RF power modules
Maintenance philosophy
Independent testing of an RF power module at the normal B+ voltage and RF power ratings requires
specialized test equipment that is not available outside of the factory. Therefore, an optional RF
power module test cable can be provided for testing and troubleshooting an RF power module
outside of the transmitter.
An RF power module may be connected to the transmitter's integral RF power module test circuitry
via a test cable, and serviced outside of the transmitter on an external work surface. In this test setup,
the B+ voltage is restricted to 48 V. This voltage is not considered hazardous to maintainers, but can
produce minor skin burns. Also, the resultant, low-level, RF output is applied to a test load and does
not contribute to the transmitter's RF output.
Special Tools and Test Equipment
The following test equipment and cables are required to troubleshoot an RF power module.
Power Module Test Kit
The power module test kit (Nautel part # 202-5015) is required to use the transmitter’s integral test
circuits. It is optionally provided by, or available from, Nautel. It contains:
• RF power module test cable (Nautel part # 202-5010).
• RF power module test load (Nautel part # 176-5720-01).
Test Equipment
Minimum required test equipment:
• A digital multimeter.
• A dual-channel oscilloscope with two 10X probes.
NOTE:
Host transmitters have a built-in RF power module test capability. If the transmitter has more
than one RF power module, an RF power module may be tested without affecting the
transmitter's on-air status.