| 摘要 |
The invention relates to a device for transmitting, at the surface, the signals from a transmitter located at a great depth. According to the invention, the antenna of the transmitter E housed in a cylindrical metal cavity, for example in the cavity of the drill stem 12 of a drill string, consists of a metal cylindrical sleeve 13 of greater diameter and shorter length than the drill stem 12, which sleeve is slipped coaxially over the drill stem while being separated from the latter by an insulating sheathing 14 surrounding the drill stem. <IMAGE> |
