A Frequency Neutralizer is a device built by Doctor Braxis, capable of blocking the signals of his pulsar generator. A device with similar properties was reverse-engineered by the Guardian Scooter.
Challenge of the GoBots cartoon
Doctor Braxis devised the device so he would be exempt from the pulsar generator, meaning he retained control of himself when the Renegades took control of Earth's population. Conquest of Earth The device was a resounding success, controlling the entire population of Earth, though Cy-Kill refused to allow Braxis to take control any of humanity until GoBotron had fallen - and threatened to remove the scientist's own neutralizer if he didn't stop annoying the Renegade. Meanwhile the Guardians Scooter and Turbo were able to recapture their mind-controlled friends A.J. and Nick. Scooter was able to devise a frequency neutralizer of his own, and after a trip to New York to scrounge up components build four of them. Two of them were placed on the cadets, returning them to their usual selves, and the group were then able to free Matt and Anya from Renegade control. Earthbound With their allies equipped with the neutralizers the Guardians were able to gain control of the pulsar generator at Cheyenne Mountain and free Earth's population.The Final Conflict