Spectrum Microwave manufactures custom Direct Digital Synthesizer (DDS) signal sources as new technology replacements for Linear Voltage Controlled Oscillators or Digitally Tuned Oscillators. An embedded microcontroller will digitize the analog control voltage or read the digital tuning word. The microcontroller will then load the proper control words into the registers of the DDS from a prom based lookup table. By carefully selecting the sampling clock of the DDS the in band spurious generated by the DDS can be minimized. An optional saw filter may be added to provide additional spur reduction. Unlike a VCO the DDS ensures perfect tuning linearity. Multiple optional outputs are also available.