HP Agilent 8563E Spectrum Analyzer 20 Hz- 26.9/50 Ghz +! opts 6,7 mixers avail.This is for 8563e agilent spec an 20 hz to 26. 9 ghz. add opt 8 sig id for an extra 300$ only. you need that for external mixing. Crt is A condition! Included is option 6 20 hz freq ext.,7 fast adc zero span sweeps. And 8 signal id for extra 300$, : A must for using external mixing. I can sell you a 33 to 50 ghz mixer for 500$. And 26 to 40 ghz for 300$, also you can upgrade to the ec version for 1000$ more. Which makes it color and have a vga out on