The Systron Donner Model 1702 is a frequency synthesizer that generates fundamental (non-harmonic) signals from 100 Hz to 999.9999 MHz in discrete 100 Hz steps. Selection of AM and FM modulation of the output is provided either by an internal 1 kHz source or by an external dc to 20 kHz source. The internal and external modulation features may be used simultaneously as well as the AM and FM inodes. The internal 1 kHz modulation source is available as a Front Panel BNC output. This feature provides many uses, including modulation drive for a FM transmitter when adjusting frequency deviation. A CW mode is also provided to allow generation of an unmodulated carrier. The Signal Generator's output is continuously variable from 0.1 µV to 1 Vrms (-127 to +13 dBm) by a Front Panel 20 dB vernier control and six step attenuator. The Signal Generator's output is protected against input/output overloads of over ±10 V peak, with Front Panel reset. Options 06 and 07 allow IEEE-488 General Purpose Interface Bus (GPIB) control of the frequency selection, mode selection, output level, step attenuator, selection and status reporting for systems integration. Information pertaining to the IEEE STD-488 GPIB as it relates to the Model 1702 is found in various chapters of this manual. The Signal Generator is normally referenced to an internal 1 MHz oscillator having a stability of 7 x 10⁻⁹ parts per day, or the high stability optional internal reference oscillator having a 3 x 10⁻⁹ parts per day stability. On the Rear Panel, one BNC connector allows monitoring of the 1 MHz reference, while an other BNC (EXT CLOCK IN) provides for inputs of external 1, 2, 5 or 10 MHz sources from a frequency standard.