- Do all Semiannual Checks
- Check for loose connections/connectors or Printed Circuit Boards that are not properly seated in card cages or edge connectors.
- Check all Wiring Harness Terminal Blocks for Loose Screws or compression contacts. Check for Heat Stress around all terminal blocks and compression contact components.
- Check Wiring Harness for cracks in the insulation, broken wires, pinched wires or indications of Heat Stress in any wiring (discoloration of wire insulation or Crimp Lug Insulators). Note: Be sure to give any High Voltage Wiring extra attention as a small pin hole is enough to cause sometimes devastating problems.
- Adjust Power Supply Voltages to Conform with Tube Manufacturer Requirements and HPA Manufacturer Requirements. *
- Adjust all trip settings to conform with Tube Manufacturer or HPA Manufacturer Requirements *
- Calibrate Metering to indicate correct Voltages, Currents, Trip Settings and RF Power measurements
- Check High Voltage Connectors for proper seating or cracks (see notes on “Rowe” type connectors in “Connectors” under “Technical Info”)
- Check Klystron Tuning (see “Tuning” Under “Klystrons” under “Technical Info”)
- Adjust Phasing in Phase Combined Systems (see “Phasing” under “Technical Info”)
* Note: Tube Manufacturer Requirements for voltages and trips Supercede HPA Manufacturer’s Requirements! Check Tube Specifications prior to installing and turning on a new TWT or Klystron.
We at Green Satellite recommend all TWT Power Supply Voltages and Power Supply Sense Circuits and Trips be set up on a “Resistive Load.” Some HPA Manufacturers claim that New TWTs can be installed without a resistive load on their systems, however, all electronic equipment fails at some time or another! It’s a fact of life. Unless you know, absolutely, that the Power Supply Voltage Meter Calibrations and Trip Circuits are correct, why take a chance that you could turn a $10K-$20K tube into a “blown fuse!”
Think of it this way...do you think the HPA manufacturers would install a tube in a new system without checking out the power supplies, the Fault Trips, and the metering if they thought there would be a chance that an expensive tube could be damaged?
If you did break a TWT because the voltages or trips were not correct, do you think they would give you another one for free to replace the damaged one?
The manufacturers use “resistive loads” in the factory to set up the power supplies, the Fault Trips, and voltage metering prior to turning on a new TWT! You should too!
We always use a “Resistive Load” to check our customer’s TWT Power Supply Voltages, Metering and Trips whether we are installing a TWT or doing Maintenance!
You may not HAVE to use a Resistive Load to maintain your system but it’s the SAFE thing to do!