Adjust dc power supply to 13.6 vdc. Simultaneously increase attenuation to avoid overloading the thermister amount. Vary applied dc voltage from 11 vdc to 14 vdc while observing indicated speed on device being tested. Indicated speed may not vary. While observing frequency counter, adjust frequency of function generator so that device being tested indicates 55 mph.
Maximum coupling is imperative.
Calculate relative sensitivity of device being tested, taking into consideration attenuation or gain of each component in the microwave path. The reflected signal passes through devices two times therefore values shall be multiplied by two. While observing frequency counter, adjust function generator for an indicated speed of 55 mph. While observing the frequency counter, adjust the function generator to each test frequency. Note and record the speed indicated on the electronic device display.