The TR4172 spectrum Analyzer is a microprocessor-controlled, intelligent instrument with a frequency range from 50 Hz to 1800 MHz. in addition to the spectrum analyzing function, the integrated tracking generator of TR4172 enables analysis of frequency response of filters, amplifiers, and so on. TR4172 is the first spectrum analyzer with a capability for measuring phase response and group delay of filters or amplifiers at resolutions of down to 0.1 deg and 0.1 ns respectively, up to a frequency of 1800 MHZ. The integrated tracking generator, along with the analyzer’ร intelligent control capability, permits correction of the analyzer's frequency response itself allowing precision level measurement. A wide dynamic range is ensured by the low higher-harmonic distortion level of 90 dB at and above 20 MHz, with respect to a signal level of -40 dBm. The display screen has a dynamic range of more than 95 dB and permits direct observation of filter responses with large attenuations. The vertical resolution of the scale can be selected from 10, 5, 2, 1, and 0.1 dB per division, observation of a ripple level of even 0.01 dB is possible with the maximum resolution setting. Use of the SAVE switch makes various measurements available, with which up to eight sets of measurement condition data are stored in the internal registers and recalled as needed. Since the internal memory is backed up by a battery, its contents remain intact even if the device is unplugged from its supply outlet. All front panel functions are remotely controllable with the GPIB interface (standard supply) for automatic measurement. The CRT display presents all pertinent measurement data. The signal response trace and measurement data on the screen can be output to an X-Y plotter simply by connecting the instrument*ร GPIB connector to the plotter'ร input with a GPIB cable and operating the relevant front-panel switches, without the need for running an output program on the GPIB controller. TR4172 also provides various convenient features to enhance measurement flexibility and efficiency, such as multiple marker, zoom, automatic centering, automatic enlargement, auto-peak search, logarithmic scaling, and four page memorized display. 1-2. FEATURES (1) Spectrum, amplitude, phase and group-delay measurement capability at resolutions of down to 10 Hz, 0.1 dB/div., 0.2 deg/div., and 0.1 ns/div. respectively. (2) Wide dynamic range of 90 dB at “40 dBm input level (above 20 MHz). (3) CRT screen with a large display dynamic range of more than 95 dB permitting direct observation of large attenuation responses. (4) Simultaneous four trace display allowing waveform comparison. (5) Multiple marker. (6) Automatic correction of bandwidth switching error, step amplifier switching error, and frequency response error. (7) Scaling the horizontal graticule divisions in logarithmic scale. (8) Output to an X-Y plotter supported without the need for the external GPIB controller. (9) Remote operation of all front panel functions via the external GPIB interface facility (standard supply). Reading capability for measurement data and labels on the screen and writing capability for characters and data on the screen.