Advantest R3968 Overview The Advantest model R3968 is a multi port box. Specifications: Frequency Accuracy: +/- 10 ppm Frequency Range: 300 kHz - 8 GHz Frequency Resolution: 1Hz Output Impedance: 50 ohms Output Power Range: -12 dBm - +13 dBm Output Resolution: .001 dB Sweep Range: 300 kHz - 8 GHz