Nautel XR12 Troubleshooting Manual

Also see for XR12: Installation manual Operation and maintenance manual Preinstallation manual

Contents

XR12 Troubleshooting Manual Responding to alarmsIssue 3.0 2009-07-28 Page 1-25Troubleshooting RF power modulesMaintenance philosophyIndependent testing of an RF power module at the normal B+ voltage and RF power ratings requiresspecialized test equipment that is not available outside of the factory. Therefore, an optional RFpower module test cable can be provided for testing and troubleshooting an RF power moduleoutside of the transmitter.An RF power module may be connected to the transmitter's integral RF power module test circuitryvia 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 canproduce minor skin burns. Also, the resultant, low-level, RF output is applied to a test load and doesnot contribute to the transmitter's RF output.Special Tools and Test EquipmentThe following test equipment and cables are required to troubleshoot an RF power module.Power Module Test KitThe power module test kit (Nautel part # 202-5015) is required to use the transmitter’s integral testcircuits. 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 EquipmentMinimum 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 morethan one RF power module, an RF power module may be tested without affecting thetransmitter's on-air status.