HP/Agilent 8406A Comb Generator

The 8406A comb generator has three internal crystal-controlled oscillators at frequencies of 1, 10, and 100 MHz, and a step recovery diode that shapes the oscillator outputs into extremely narrow pulses less than 100 picoseconds wide. The result is the generation of a comb of marker frequencies with useful amplitude from 1 MHz to beyond 5 GHz.