There are at least 2 artists called RTX.
1) A follow-up to Royal Trux
2) An anonymous french techno producer, also called Rootstrax

1) Just over four years after Neil Hagerty and Jennifer Herrema disbanded the original version of Royal Trux, Herrema returned to music with RTX, a band that applied the swagger and snarl of Accelerator-era Trux to a different lineup. Nadav Eisenmann and Jaimo Welch joined Herrema on RTX's debut, Transmaniacon, which was released by Royal Trux's longtime label, Drag City, in fall 2004. Brian McKinley and Kurt Midness joined the fold for 2007's Western Xterminator, an even grittier, more potent distillation of Herrema and company's sound.

2) http://www.discogs.com/artist/Rootstrax