At the University of Maryland we have been studying high power amplification in funda- mental mode X-Band gyroklystrons for several years [1,2]. This investigation has culminated in peak powers near 27 MW with good efficiency and gain . The nominal operating pa- rameters include 425 kV, 160-200 A beam with an average perpendicular to parallel velocity ratio of a :::-_, 1.0. In an attempt to produce even higher power levels and higher frequencies, we have recently designed a series of experiments to study second harmonic gyroklystrons. The initial tubes will utilize the existing beam formation system (electron gun, magnets, input cavity, etc.) and an output cavity designed to operate at 19.7 GHz in the 11E02 mode. Later tubes will use a new electron gun designed to produce a 500 kV, 550-750 A beam with a r-,-, 1.5. In this paper we will describe the design and operation of the first tube and indicate steps that are being undertaken to improve performance.