GANG TUNER FOR A MULTICAVITY MICROWAVE TUBE

• Main Authors: ROBERT C. SCHMIDT, WALTER E. NELSON
• Format: Patent
• Language: English
• Published: 02.11.1971
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRICITY

1,195,829. Velocity-modulated tubes. VARIAN ASSOCIATES. 30 May, 1969 [21 June, 1968], No. 27587/69. Heading H1D. Gang-tuning of a plurality of cavities of a multicavity microwave tube, to stagger-tune them about any one of a plurality of set frequencies, is effected by an arrangement of cams and cam followers, one pair for each cavity, the cams being disengageable from the cam followers and mechanically interconnected to permit synchronous rotation to a different setting only when so disengaged, whereby to avoid wear of the engaging surfaces during operation of the tuner. As shown, the successive cavities 5 of a magnetically focused klystron are tuned by plungers 22, 23 connected to rods 28 the vertical positions of which are determined by the abutment of their upper ends against corresponding cam screws 27 mounted in a set of engaging gear-wheels 26 rotatable by knob 46. A yoke plate 34 is mounted upon screws 35 and is movable in the vertical direction by rotation of knob 39. Leaf springs 43 are secured at their centres one to each tuning rod 28, and at their ends to a yoke plate 34, whereby vertical adjustment of the latter by knob 39 permits the engagement or the disengagement of the rods from their associated screws 27, the receipt of a flattened end portion of the rod 47 within a slot 52 of a block 51 mounted on the yoke plate ensuring that the gear-wheels cannot be rotated by knob 46 until the yoke plate has been lowered sufficiently to disengage all the tuning rods 28 from their respective screws 27. Access apertures are provided in alignment with the ends of the rods 28, to permit initial adjustment, by screwdriver, of screws 27 to provide the desired stagger tuning about the plurality of desired set frequencies, after which the screws are locked in position. In a modified arrangement (Fig. 5, not shown), the engagement and disengagement of the plunger rods with the cam screws is effected by applying fluid to an appropriate side of a set of pistons mounted within hydraulic cylinders. Reference is also made to tuning the cavities by deforming their walls.