Some of the output windows on the accelerator klystrons failed because of the poor solder fillet between the ceramic and the copper tube to which it is brazed. Two optimum adjustments of the focusing fields of the special K-14 klystron were found. The lower adjustment gave a transmission of 85 to 93 as the beam voltage was raised from 180 to 365 kv. The higher adjustment gave almost a constant 93 transmission. These figures were obtained without RF drive. With drive present, the higher value yielded a greater output, but the lower value gave greater RF gain. The klystron with a high-efficiency collector was successfully operated. Measurements were made of the output power and bunching parameter in the gridless traveling-wave klystron. The output power was smaller than predicted. The gridded duplex traveling-wave tube was assembled with the use of Araldite. The tube now holds a vacuum of 4 x 10-7 mm Hg. In tests, 65 of the beam was collected at the collector after passing through 5 rows of grids without any focusing voltages. At 4 amp of beam current, the bottom row of grids a color temperature of 800 deg C.