| 摘要 |
PURPOSE:To set the direction of an antenna in a short time by using an annular or curved level for displaying the elevation of the antenna. CONSTITUTION:The antenna 10 is fixed 14 with a screw 14 turnably around a supporter 13. The antenna 10 is fitted with a display device 18 for indicating its inclination. The display device is made of annular or curved glass. It is filled with liquid, wherein there is a small air bubble. The display device has a scale on its surface to indicate the inclination of the antenna 10. The air bubble moves according to the inclination of the antenna 10. Then, the air bubble on the scale is read to know the elevation of the antenna 10. |
