The 5340A Automatic Microwave Counter measures frequencies from 10 Hz to 18 GHz with sensitivities of -30 dBm (10Hz to 500MHz), -35 dBm (500MHz to 10GHz), and -25 dBm (10 to 18GHz). Input impedance of 50 ohms. Timebase crystal frequency of 10 MHz with an aging rate <3x10E-07/month. Basic accuracy of ?(1 count + time base error), resolution of 1MHz, 100kHz, 1kHz, 100Hz, 10Hz or 1Hz.