• FM, PM and NPR Calculations

      Gallupe, Gary; APCOM, Inc. (International Foundation for Telemetering, 1993-10)
      System performance can be ascertained via a number of parameters; one of which is Signal-to-Noise ratio (SNR). SNR is the ratio of the value of the signal to the value of the noise. It is generally expressed in decibels and usually a function of the system bandwidth. Another measure of performance is the Noise-Power ratio (NPR). NPR is the ratio of the noise level within a specific measurement channel when noise is applied to all channels, to the level that is measured within the specific channel with noise applied to all of the channels but not the specific channel.
    • PRE-DETECTION CONVERTERS FOR TAPE RECORDERS

      Gallupe, Gary; APCOM, Inc. (International Foundation for Telemetering, 1993-10)
      RF and IF signals must be down-converted to lower frequencies to allow storage on tape. Pre-Detection converters avoid signal distortion created in later receiver stages, however should not add noise and distortion with their conversion process.