Test Set Equipment The extreme accuracy possible with the Andrew reflectometer will be realized only when it is used with high quality test equipment. A typical arrangement is shown in Figure 2. The RF input and the incident energy sample -10 dB are part of the coaxial directional coupler. Both ports are Type SMA adaptor (female). The reflector energy port is also a Type SMA adaptor (female). The RF level at this port will be a 6 dB lower than the difference between the input level and the measured return loss. The test port matches the specified waveguide size. The energy level is 3 dB less than the incident power.

Caution: Return the reflectometer to the factory for any service. The transitions, coupler, internal loads, and detectors are turned and calibrated as a unit. Disassembly and reassembly of any of these parts could seriously degrade the extreme accuracy built into the unit. Equipment Calibration Before making a measurement, it is necessary to calibrate the test equipment read-out unit against a known value at a number of discrete frequency points across the frequency band. Calibration is provided by a sliding, calibrated, mismatched load that has precisely known values of return loss at sufficent points to determine the characteristics. First, calibrate the sweep equipment internally

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