The HP - Agilent SNS series N4000A is 10 MHz to 18 GHz noise source with nominal ENR 6dB. The N4000A noise source is designed for accurately measuring devices with low noise figure, or devices whose gain is especially sensitive to small changes in source impedance. The N4000A noise source has a choice of connectors, with an APC 3.5(m) connector as standard. Option 001 N-connector