DESCRIPTION 1-16. The HP Model 8746B S-Parameter Test Set contains the necessary microwave circuits for measuring all four s-parameters of an active or passive two-port device from 0.5 to 12.4 GHz. ~he Model 8746B is designed primarily to be used WIth the Hewlett-Packard Model 11608A Transistor Fixture. However, measurements on other microwave devices may also be made by inserting the necessary coaxial line-lengths in the rea: panel refere?ce line. The Model 8746B is used WIth a compatIble phase-amplitude· ratio indicator, such as the HP Model 8410A Network Analyzer or Model 8405A Vector Voltmeter. Measuring circuits for each s-parameter are automatically set with front-panel pushbuttons or with remote-contact closures. Attenuation of the incident RF signals can also be set with front-panel pushbuttons or remote contact-closures. Figure 3-4 is a diagram of the RF circuits for the standard 8746B.