| 摘要 |
PURPOSE:To enable the jointing between a dielectric rod and an outercasing through brazing, by making the depth of the first outer metal casing thin to contact with the outer-circumference of the first dielectric rod while locating second dielectric rod which faces with the first rod at the outside of said outer casing. CONSTITUTION:A helix 3 supported by a dielectric rod 2 is located in a thin metal outer casing 4 at the portion contacting with the dielectric rod 2, while another dielectric rod 5 is provided at the outside of the metal outer casing 4. The portion of the outer casing 4 contacting with the dielectric rod 2 of the outer casing 4 is thin as described above and another dielectric rod 5 is provided at the outside of the outer casing 4. Consequently the distortion due to differential expansion when performing the jointing through brazing is absorbed by the thin portion of the outer casing, while since it is reinforced by the outer dielectric rod sufficient strength is obtained, while furthermore since the outer casing will cover a portion of the outercircumference of the dielectric rod 2 the heat transmission can be considerably improved. |
