Frequency characteristics in resonance at self-oscillation harmonics

The frequency characteristics of a Thomson generator coupled inductively to a resonance loop of frequency close to a harmonic frequency are investigated theoretically and experimentally. It is shown that the character of the frequency dependence is different for tying at the harmonic frequency and at the fundamental tone; the difference corresponds to an additional phase shift of $\pi/2$. Some mechanisms leading to asymmetry of the frequency curve are considered.