I recently needed a hex editor on an older machine running an older OpenSUSE. I did an alt-f2 and typed "hex" and okteta (KDE hex editor) was in the list. I was not familar with okteta. Unfortunately it failed, and by that I mean, it just went away --- probably due to the file size. I did some searches and found a wiki page: http://en.wikipedia.org/wiki/Comparison_of_hex_editors. I sorted by linux. Bottom-line, I used heme. It was super simple to compile (few requirements) and use, quick, and did the job. For a successful compile, I did have to make the change to ncurses, as described in the FAQ.

http://sourceforge.net/projects/heme/
http://heme.sourceforge.net/faq.html