Wide-band three-phase RC-generators for complex measurements of two-poles and four-poles

From a 3-phase R-C oscillator two voltages are derived, the complex ratio of which can be varied. The complex ratio is independent of the frequency. The two voltages are used in a compensation circuit for measuring the parameters of two-poles and four-poles. Two equipments are described covering the frequency ranges 20 c/s¿22 kc/s and 22 kc/s¿10 Mc/s. The possible error is ±0.5 db and ± 2° in the frequency range 100 c/s¿3 Mc/s. Outside this range the phase error may increase about 3 times while the amplitude error remains nearly the same.