The ADRET 5104 synthesizer is a synthesis-technique programmable master oscillator covering the band from 90 to 120 MHz with 10 Hz resolution and a stability of 2 parts in 100000000 per day. The output frequency, intended for the control of hyperfrequency sources such as those used in satellite communications facilities, is available on a coaxial connector on the rear of the instrument at a fixed level of + 13 dBm/50Ω. The output frequency may be set either manually on seven decimal switches or remotely, by an externally- generated program fed to a rear-panel connector.