The Appleton-Hartree magneto-ionic theory predicts that interference from ground-based transmitters can be registered at satellite orbiting above the F layer peak when foF2 < √2 fcF2 (foF2-peak plasma frequency in the F2 layer below the satellite, fcF2 - electron gyrofrequency at the F2 peak). In spite of this, on the board of the Intercosmos-19 satellite, active from March 1979 to March 1981, the enhancement of radio emission in the whole frequency band of fc < f < foF2 (fc - local electron gyrofrequency, close to satellite), was observed. The same type of emission, was also registered on the board of the Cosmos-1809 satellite launched in December 1986. The comparison of these two observations supports the hypothesis that the ground based transmitters act as a powerful permanent ionospheric excitor which induces electrostatic and electromagnetic waves in the topside ionosphere. The possible physical mechanisms are briefly discussed.