Abstract: 1. The method for producing radio-frequency signals for jamming the detecs in twin channel type variable-time proximity fuzes comprising the steps of detecting a first radio-frequency signal radiated from said variable-time proximity type fuze within a first prescribed range of frequencies, alternately detecting said first signal and a second radio-frequency signal radiated from said fuze within a second prescribed frequency range, the alternating rate being at a frequency mucn higher than the band-pass of the said variable-time fuze detectors, delaying each of said detected signals a prescribed time in the order that they are detected, sequentially deriving from said delayed detected signals respective radio-frequency signals having frequencies equal to said first and second fuze radiated signals respectively, and alternately transmitting said derived radio frequencies at said alternating rate for a time equal to said delay time to provide interleaved transmitted signals.