Agilent 8648B signal generator upgraded to 4 GHz 1E5 1EA serial 1401 Frequency 9 kHz to 4000 MHz Resolution 1 Hz ( 10 Hz on display ) Amplitude -137 dBm to +20 dBm in steps of 0.1 dB Modulation AM, FM, PM external AC,DC, 400 Hz, 1 kHz 50 Watt reverse power protection GPIB interface Has option : 1E5 Oven timebase, 1EA High power output VFD display ( weak )