| 摘要 |
A multistage extensible rod antenna system including a plurality of conductive rods which have different diameters, respectively, and are connected in a freely slidable manner to each other. Each of the conductive rods is provided, along its inner circumferential wall of the upper end portion, with first and second stepped portions of different diameters. The first and second stepped portions hold a first collar and a second collar, respectively with an elastic sealing ring therebetween. The upper end face of each of the rods is formed into an engaging portion to keep the collar from slipping off. The multistage extensible rod antenna system thus structured creates less compressive force on the elastic sealing ring, prolonging the elasticity of the sealing ring and extending the service life of the multistage extensible rod antenna system.
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