Noise, distortion and transmission characteristics of an M-BWO

Performance measurements have been made on an experimental FM transmitter using M-BWO. The attractive features of this oscillator are variable power control, high efficiency, wideband modulation capability and light weight. The lack of published data describing the performance of the M-BWO in terms of spectral noise distribution, spurious signals, two-tone third-order distortion, noise power ratio, instantaneous bandwidth and wide bandwidth transmission capabilities has resulted in this investigation. Performance data were obtained with an M-BWO transmitter possessing a residual FM of less than 50 KC. Spurious signals present were found to be greater than --40 db for output powers of 50 watts. Two-tone third-order distortion values varied from 1 to 2% (-37 to --40 db) and noise power ratios measured from --20 to --28 db for an rms frequency deviation of 30 MHz.