The TF2091B Noise Generator and the TF2092B Noise Measuring Receiver make up the OA2090B White Noise Test Set. This set can be used to completely noise load a 6 to 1200 channel frequency multiplexed, FDM, and radio communications system. The TF2091B Noise Generator, when equipped with a complement of up to nine of the appropriate high pass, bandstop, and low pass filters, fully noise loads your system across its baseband. Typically, the bandstop filters are selected to test at distributed points across the baseband such as low, mid, and high channels. The TF2092B Noise Receiver, when equipped with bandpass filters and local oscillators, with the same frequencies as the bandstop filters in the noise generator, measures the noise injected into selected channels by the intermodulation distortions and thermal noise of the radio/amplifiers system. The baseline NPR (noise power ratio) of the system can be determined during initial installation testing or commissioning. Or, inservice testing can be done on a quiet or out-of-band channel. Specifications include: noise band 12kHz to 12360kHz, noise power level -14.5 dBm/kHz, total power to +20 dBm, 75 ohms output impedance, effective receiver bandwidth 2.2kHz, NPR to 75 dB..