1. Other precautions taken when tuning a klystron include using nonferrous tools. 2. But in older transmitters tetrodes or klystrons are also utilized. 3. A klystron is a specialized linear-beam vacuum tube. 4. After some distance into the resonator, repeatedly reflex klystrons . 5. In the reflex klystron the electron beam passes through a single resonant cavity. 6. Two differences from the klystron give it a lower cost and higher efficiency. 7. Microwave tube designers used to take numerous steps to reduce microphonism in klystrons . 8. This was essentially a conventional two-cavity klystron with one cavity removed. 9. The klystron was invented by the brothers Russell and Sigurd Varian at Stanford University. 10. These accelerators are typically powered by klystrons , which require a high voltage supply.