Which of the following is not a system EP technique?

Variable Polarization is indeed not classified as an Electronic Protection (EP) technique. EP techniques are primarily designed to protect systems from detection, jamming, and other electronic threats by enhancing their survivability in contested environments.

Frequency Diversity involves using a range of frequencies to transmit data, making it harder for adversaries to jam or intercept the signal effectively. Passive Detection utilizes the natural signals emitted by systems or the environment to gather information without revealing one’s own position, which is crucial for maintaining operational security. Home on Jam refers to a technique used in certain homing systems that allows them to lock onto a jamming signal, which can be used to counteract or evade jamming efforts.

In contrast, Variable Polarization does not fit within the core functions of electronic protection but rather pertains to techniques that may be used in signal transmission contexts or specific communication methods without directly offering protection against electronic warfare threats.