I came across this older, discontinued TBC from a currently existing company that I never saw mentioned before. They made a series of these "VooDoo: TBC's starting back in 2001. The specs claim a 5.8 MHz bandwidth, but only a 42 S/N ratio;

http://support.keywesttechnology.com/

(Change selection from "Files" to "Manuals". Ten products under VooDoo are listed)