This Programmable Function Generator uses direct digital synthesis to provide high performance and extensive facilities at a breakthrough price. It can generate a variety of waveforms between 0.1 mHz and 10MHz with a resolution of 7 digits and an accuracy better than 10ppm. Direct digital synthesis for accuracy & stability Direct digital synthesis (DDS) is a technique for generating waveforms digitally using a phase accumulator, a look-up table and a DAC. The accuracy and stability of the resulting waveforms is related to that of the crystal master clock. The DDS generator offers not only exceptional accuracy-and stability but also high spectral purity, low phase noise and excellent frequency agility. A wide range of waveforms High quality sine, square and pulse waveforms can be generated over the full frequency range of 0.1 mHz to 10MHz. Triangle waveforms, ramp waveforms and multi-level squarewaves can also be generated but with limitations as to the maximum useable frequencies. Variable symmetry/duty-cycle is available for all standard waveforms. Arbitrary waveform capability Arbitrary waveforms can be loaded via the digital interfaces and then used in a similar way to the standard waveforms. Up to five arbitrary waveforms of 1024 10-bit words can be stored in non-volatile memory. The waveform clock is 27.48MHz maximum. This facility considerably expands the versatility of the instrument making it suitable for the generation of highly complex waveform patterns. In addition, numerous “complex” waveforms are pre-defined in ROM, including commonly used waveshapes such as sinex/x, exponentially decaying sinewave, etc. Sweep All waveforms can be swept over their full frequency range at a rate variable between 10 milliseconds and 15 minutes. The sweep is fully phase continuous. Sweep can be linear or logarithmic, single or continuous. Single sweeps can be triggered from the front panel, the trigger input, or the digital interfaces. Two sweep markers are provided. am Amplitude Modulation is available for all waveforms and is variable in 1% steps up to 100%. An internal AM source 4s incorporated. Alternatively modulation can be controlled from an external generator. FSK Frequency Shift Keying provides phase coherent switching between two selected frequencies at a rate defined by the switching signal source. The rate can be set from dc to 50kHz internally, or dc to 1MHz externally.