This is one of a series of Frequency-Range-Specific Direct Digital Synthesis (DDS) RF Signal Generator/ Amplifiers for Industrial Faraday Cage Builder ETS Lindgren.
ETS Lindgren (ETSL) builds Faraday Cage (Electromagnetic Dark Rooms) for various purposes around the world. Applications include cell-phone towers, MRI rooms, radio-telescope and radar installations and broadcast transmitters. If an enclosure room is "leaky" from an RF point-of-view: the wrong signals get amplified and transmitted.
These units are used by ETSL technicians worldwide for a variety of tasks, all related to testing the shielding effectiveness of their enclosures as they are being built for customers like AT&T, Verison, T-Mobile, Siemens and GE Medicalm NASA and the like. Think of these generators as electronic squirt-guns trying to find leaks! Without tools such as these--assuring effective shielding to NIST standards would be impossible.
Control Alt Design not only faced the expected tasks of building the electronics that would synthesize and amplify a particular HF or UHF frequency, but also faced the challenge that these instruments faced daily air-shipping (remember the old Samsonite Gorilla ads?) and frequent falls from ladders. The requirement for ruggedness resulted in some novel and very successful engineering!