Abstract We present hardware to measure longitudinal cooling times of electron cooled ion beams in CELSIUS. The measurements are performed by an a fast ADC and a AD6620 receiver signal processor evaluation board that we interfaced to a Linux PC. The specialized signal processors are developed for third generation mobile phone systems and consist of several digital mixing, filtering, and downsampling stages. We describe the measurements and the hardware that allows us to record and analyze high resolution spectra at very high update rates
