Classical harmonic oscillator with quantum energy spectrum
  The classical dynamical system possessing a quantum spectrum of energy and "quantum" behavior is suggested and investigated. The proposed model can be considered as a dynamical variant of the old quantum theory for harmonic oscillator in which the Bohr-Sommerfeld quantization rule is absent and "quantum-mechanical" properties are the result of system behavior itself. For this dynamical system the classical model of Franck-Hertz experiment which allows explaining the experimentally observed regularities is suggested and investigated. The examples of calculations of Franck-Hertz experiment of within the limits of the suggested model of classical dynamical system are presented. 
Sergey A. Rashkovskiy
quant-ph