| 摘要 |
PROBLEM TO BE SOLVED: To prevent the change of an inductance due to a vibration and secular change by permitting a telescope-shaped, extension/contraction possible and cylindrical element to be the lowest stage of an antenna element, integratedly molding an upper tube conductor and a lower tube conductor with a frequency band separating hollow insulated cylinder where a coil is wound and covering the outer periphery by means of a resin pipe. SOLUTION: A loading coil 13 is wound inside a helical groove which is formed in the outer periphery of the resin pipe 12. An insert resin 16 is integratedly molded in the outer periphery of the resin pipe 12 where the loading coil 13 is formed and the outer periphery of a part in the lower tube conductor 11-A connected to the loading coil 13 and the upper tube conductor 11-B. The lower tube conductor 11-A and the upper tube conductor 11-B are mechanically joined with the frequency band separating loading coil 13 by integrated molding by the insert resin 16, the mechanical strength of a first element 1 is improved, the winding interval of the loading coil 13 is fixed even at the time of a vibration and the fluctuation of the inductance is prevented. |
