Conversion of periodic-signal frequencies by means of time coincidence circuits

Conclusions

• 1 The above pulse coincidence method can be used for measuring oscillator frequency drifting, frequency deviations, and frequency differences of two signals. The method is suitable for indicating a sign of the oscillator frequency drift or the frequency difference, as well as for checking the modulation symmetry of FM signals. The measurement error in this case is comparable to the errors of known methods and amounts approximately to 1–2%.

• 2 The utilization in the above method of three coincidence circuits for evaluating the sign of the difference frequency is suitable for extending its application to any relationship of input frequencies, as distinct from the method which is described in [2], is provided with two coincidence circuits and is applicable for investigating only small signal frequency differences.

• 3 The above method, as distinct from [2], is suitable for measuring any frequency of the difference-frequency sign variations. Moreover, it is sufficient that the number of coincidences over half a period of frequency variations should be greater than or equal to two.