8514B: 45 MHz to 20 GHz, 3.5 mm connectors 8515A: 45 MHz to 26.5 GHz, 3.5 mm connectors 8516A: 45 MHz to 40 GHz, 2.4 mm connectors (Discontinued) 8517B: 45 MHz to 50 GHz, 2.4 mm connectors Separate reference channel for each incident port Built-in electronic switch The Keysight S-Parameter Test Sets are available for the 8510 Network Analyzer for broadband coaxial measurements from 45 MHz to 50 GHz. The test set has an architecture that develops a separate reference channel for each incident port. RF switching is done with a built-in electronic switch. For active device measurements, the test set includes the ability to apply dc bias (external) to the test port center conductors.