Due to its wide frequency range of 500kHz to 1.3GHz and directivity of >/=40 dB, the 8503B S-Parameter Test Set is considered one of the best in the industry. Frequency response: Transmission (S1, S2): ±1 dB, ±12º from 0.5 to 1300MHz Reflection (S1, S2): ±2 dB, ±20º from 0.5 to 1300MHz), ±15º from 2 to 1300MHz. Maximum operating level of ±20 dBm. Connectors: Test ports, 75 ohm APC-7, all other RF connectors, 75 ohm Type N(F) bias inputs, BNC female. DC bias input: ±30 VDC, ±200 mA.