Compact single conductor transmission line transducer for telemetry in borehole drilling

A borehole drilling communication system, comprising:

• a hydraulic drill that includes a drill pipe extending from a first end to a second end, and having a drill head located at the second end of the drill pipe;
• a communication module located on the drill pipe at the drill head;
• a transducer having an input end and being mounted on the drill pipe at the drill head adjacent the communication module, wherein the communication module includes a first output terminal electrically connected to the drill pipe and a second output terminal electrically connected to the input end of the transducer;
• wherein the transducer comprises a helical conductor that is positioned coaxially over a section of the drill pipe at the drill head and that extends helically over the drill pipe for a distance from the input end and in a direction away from the second end, the helical conductor terminating at an electrically isolated free end;
• whereby, during use in borehole drilling, data sent from the communication module is launched by the transducer and transmitted along the drill pipe as a single conductor transmission line.