Apparatus and method for routing a transmission line through a downhole tool

A method for routing a transmission line through a tool joint of a downhole tool, wherein the tool joint includes a primary and a more internal secondary shoulders, a tool wall, a central bore, and a longitudinal axis, the method comprising:

• increasing the inside diameter of a portion of the central bore to provide a first portion having a standard diameter, and a second portion having an enlarged diameter;
• and
• drilling a channel at a nominal positive angle with respect to the longitudinal axis through the tool wall from the secondary shoulder to an exit point within the second portion.

A method for routing a transmission line through a downhole tool having primary and secondary shoulders, a central bore, and a longitudinal axis, the method comprising:

• drilling a straight channel through the downhole tool at a positive nominal angle with respect to the longitudinal axis from the secondary shoulder to a point proximate the inside wall of the central bore;
• and
• milling back, from within the central bore, a second channel effective to merge with the straight channel, to form a continuous channel from the secondary shoulder to the central bore.

The method of claim 32, wherein a backing member is inserted into the central bore to facilitate drilling the straight channel as it breaks out into the central bore.