10 MHz to 1.8 GHz, Vector Signal Analyzer RF Section. Option AY8 convert HP 89410A to an HP 89440A. The Agilent 89430A increases the frequency range of the HP 89410A from dc - 10 MHz to 2 MHz - 1800 MHz. And increases the scalar frequency span on the top end from 10 MHz to 1798 MHz. Noise, amplitude and accuracy also improve.