3EH7/XF183 is a miniature hight voltage tube made by RCA. It is a directly heated, sharp cut-off pentode operated as an oscillator or amplifier in the range from 30MHz to 65MHz. It has a grid2 range of -2.5 to -7 volts, an anode voltage of 0.7to 4.5kV, a peak plate current of 10mA, and a grid1 voltage of -3.5 to -22 volts. It is designed for use in applications such as AC mains transmission, TV receivers, RF amplifiers, FM tuners, and other high frequency circuits.