PURPOSE: To reduce the fluctuation of RF output frequency by performing frequency control which employs a PLL(phase locked loop)/prescaler.

CONSTITUTION: This stabilizer is comprised of an RF signal input terminal 1, a television tuner 2, a band-pass filter(BPF) 4, a first PLL/pre-sealer 5, a control microcomputer 6, a second PLL/pre-scaler 8. and an RF output terminal 12. The local oscillation frequency of the tuner 2 is directly controlled by using the first PLL/pre-scaler 5 with high correction accuracy for phase fluctuation instead of an AFT(automatic frequency tuning) comparator. Thereby, it is possible to improve the frequency accuracy of RF converter output by improving the frequency stability of an intermediate frequency signal.