Overdrive monitor for HF measurement amplifier - has detectors for each successive stage operating with narrower bandwidth

摘要

The protection against overdrive of h.f. amplifiers in measurement units is based on detectors at each stage operating with a restricted bandwidth. The detectors are connected to a common evaluation circuit and an indicator is provided either for each detector or one common unit for all of them. The setter of stepwise changing of gain is automatically set for limiting overdrive, and the response time of detectors is selected to be shorter than the pulse period of the preceding stage. The detectors are connected after the mixer for sensing the difference and sum of frequencies.