This test method applies to the measurement of unwanted radio frequency energy emitted from electron tubes designed to operate in the microwave region of 100 MHZ to 30 GHZ. It is assumed that the frequency@ location and intensity of the leakage has been generally defined@ using broadband equipment@ and harmonics of the fundamental frequency and spurious (non-harmonic) leakage have bean examined and generally defined. Purpose To obtain the characteristic and level of radio frequency leakage from microwave tubes when these tubes are operated at operating parameters I as specified on the Tube Specification Sheet (TSS) without additional shielding.