PKI 4420 is a spectrum analyzer that scans from 1MHz to 13.4GHz in 0.5 seconds. The detected signals are displayed on the screen in cascade mode. The very high sensitivity, adjustable in 5 steps down to -80dBm, allows to pick up the signals in the adjacent environment or to limit the sensitivity as close as possible to the source. The tune list function makes it possible to focus the analysis on a detected signal and display it „live“.

The results are recorded and time-stamped. A background signal memory function allows comparisons with previous analysis. The new signals are displayed separately. the display in „Persistence“ mode shows the new signals in blue and then in red depending on their persistence.