TB 9-4931-523-35
NOTE
Use waveguide to coaxial adapters when TI is waveguide.
NOTE
Use 50Ω-to-75Ω or 50Ω-to-93Ω adapters when TI is 75Ω or
93Ω.
(3) Establish a reference on the receiver system at test frequency recorded in 7a
above.
(4) Set TI for 0 dB or minimum attenuation and insert TI between POINTS A and B
NOTE
Ensure receiver system is in measurement mode.
(5) Measure and record receiver system indication as insertion loss. This value will
(6) Establish a new reference on receiver system.
(7) Increase TI attenuation setting in one step increments (or one cardinal point as
desired).
(8) Measure and record attenuation change. Measured attenuation will be within
range and accuracies specified in appendix A for TI being calibrated.
(9) Repeat (7) and (8) above for each setting on TI dial or other desired settings.
(10) Disconnect TI from equipment setup and repeat (1) through (9) above for
remaining frequencies listed in 7a above.
NOTE
Remove 10 dB attenuator (fixed) from figure 1 equipment setup
and establish a new reference on receiver system when making
measurements below -70 dB.
b. Adjustments. No adjustments can be made; however, a correction chart may be
prepared listing actual receiver system indications at frequencies of interest.
10. Fixed Attenuation
Measurement (18 to
26.5 GHz)
a. Performance Check
above and RF LEVEL output control for +3 dBm.
measurement by calculating the following equation: