| 摘要 |
PURPOSE:To prevent disturbance between antennas by providing a magnetic shield box whose opening is formed to a face opposite to a cabin and providing a pickup coil in said box so as to eliminate various inconveniences caused by projecting an antenna to the outside of the cabin. CONSTITUTION:The opening 12 is provided to the magnetic shield box 10, and the box 10 is fixed in the cabin so that the opening face is placed nearly in opposition to the cabin 14. The pickup coil 16 is provided nearly in opposition to the opening 12, a variable capacitor 18 is connected as a loop and a part of the loop is connected to the box 10 and a core 20b of a coaxial cable 20 whose earth outer wire 20a is fixed to the box 10. Thus, when an induced current is formed to the cabin by a received radio wave, the magnetic field by said current is picked up by the coil 16. |
