The features of nonlinear processes in oscillators with two synchronous modes open a new way of frequency stabilization as in such oscillators the correlated normal frequencies' shifts of the same sign arising, for instance, due to temperature variations or active device reactance perturbations tend to compensate each other in respect of their influence on an oscillation period [1 ]. This paper deals with experimental verification of the theory. Two cases of a harmonic ratio, 1:2 and 1:3, are investigated. The used RF model incorporates a transistor one-pole negative conductance active device loaded on a LC-filter with two about multiple resonant frequencies. Both harmonic ratios provide easy and reproducible tuning at the compensation regime. The most remarkable demonstration of the discussed phenomenon takes place when the oscillator is overcompensated as in this situation an oscillation frequency grows while a capacitor shunting the active device output is being increased. Frequency stability gain in excess of 40 dB in rather wide range of parameters is registered in some tests.
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