TRAVELING WAVE TUBE AMPLIFIERS ARE SPECIFICALLY DESIGNED FOR GENERAL PURPOSE SYSTEM, COMPONENT TESTING, LABORATORY EXPERIMENTATION AND MEASUREMENT. A TWT IS A VACUUM FILLED TUBE OR PACKAGED WITH A POWER SUPPLIES AND OTHER ACTIVE/PASSIVE MICROWAVE COMPONENTS. THEY ARE USED IN ECM TEST CHAMBER AND FOR LABORATORY TESTING WHERE HIGH POWER IS REQUIRED.

CLASSIFICATION IS DETERMINED BY THE PROVIISIONS OF GIRS 1 AND 6 OF THE COMBINED NOMENCLATURE AND THE TERMS OF HEADING 8540, 854079 AND 85407900 Other Microwave tubes (for example, magnetrons, klystrons, travelling wave tubes, carcinotrons), excluding grid-controlled tubes