Dr. Siegfried Knorr and Dr. Betty Chang founded Colby Instruments in 1977. The original focus of the company was to manufacture test equipment for the microwave and radiofrequency (RF) markets. In the brand’s first 10 years, Colby Instruments developed high-speed pulse signal generators and clock drivers. From there, Colby introduced product lines of phase shifters and programmable delay line instruments that swiftly became popular tools in their field. Engineers, technicians, and maintenance professionals in many industries trust Colby Instruments as their manufacturer for precise, accurate instrumentation. ValueTronics is proud to sell used and refurbished Colby Instruments test equipment at affordable, cost-effective prices.