An apparatus for retaining a transmission line within a drill string component includes a drill string component comprising a bore having an internal diameter. A slot is formed in the internal diameter to receive a transmission line. A first feature within the slot is configured to engage a corresponding second feature on the transmission line and thereby retain an end of the transmission line. The first feature comprises a first angled surface configured to contact and engage a corresponding second angled surface of the second feature. The first and second angled surfaces are oriented such to keep the transmission line retained within the slot when tension is placed on the transmission line. A corresponding system is also disclosed.