Disclosed is a very low frequency test generator for generating a high voltage having a low frequency in order to test the insulation of capacitive loads, in particular power cables. Said VLF test generator comprises an oscillator part which generates a high voltage that has a high frequency and is modulated with a lower frequency at an output, and a demodulator which is connected to the oscillator part, demodulates the high voltage, and recovers the low frequency therefrom. A discharge resistor for the capacitive load is connected in parallel to the demodulator, said discharge resistor conducting back to the aforementioned output.