У вашего броузера проблема в совместимости с HTML5
This unit as built works from: 100khz - 100mhz
https://kb8ojh.net/projects/noisegen/
A noise generator is a circuit that produces electrical noise (i.e., a random signal). Noise generators are used to test signals for measuring noise figure, frequency response, and other parameters. Noise generators are also used for generating random numbers
It’s often handy to have an RF noise generator when testing various circuits, especially filters.
https://en.wikipedia.org/wiki/Noise_generator