| 摘要 |
PURPOSE:To improve S/N rario of a receiving signal from underground by burrying one electrode of an ultralong wave communication into the front end of a casing pipe, and burrying the other electrode into a vertical shaft provided at a certain distance from the pipe with approximately the same depth as that of one electrode. CONSTITUTION:One electrode 17a of an ultralong wave communication antenna 16 is mounted to the front end of a casing pipe 4 through an insulation case, and the other electrode 17b is burried into a vertical shaft 19 provided at a certain distance from the pipe 4 with approximately the same depth as that of the electrode 17a. By the receiving antenna 16 formed in such a way, an ultralong wave electromagnetic wave is received from underground at a position where an earth current generating from an electric equipment on a rib is damped to transmit it to an amplifier 12. According to the constitution, long distance signal transmission from the deeper depth can be ensured and, at the same time, reliability can be promoted. |
