Theoretical fluxes compared to the observed 3 mm fluxes of Cyg OB2 #8A, plotted as a function of orbital phase in the 21.908-day binary period. The black symbols with error bars show the observed data. Open symbols indicate duplications in the extended phase range (as in Fig. 2). The dark blue curve is the synchrotron model, the red curve the adiabatic thermal emission model, the green curve the radiative thermal emission model, and the light blue curve the combined synchrotron and adiabatic thermal emission model.