Permits excitation of two 807 or equivalent tubes. Employs three tubes: a 6J5-GT « Clapp » oscillator, a 6AU6 buffer-multiplier for the 10-, 15- and 20-meter band, and a 6L6-G driver-multiplier for the same bands. Oscilla­tor tuning is achieved by means of a variable tuning condenser, the different sections of which are switched in according to necessity. Exact calibration is accomplished through adjustment of the trimmer condensers and the variable Inductances. The plate tuning circuit of the driver has a coil for each frequency range, adjustable to the center of the frequency range in use. The level produced by the driver may be adjusted within certain limits by varying the voltage applied to the screen grid of this tube