Sine waves over 10 seconds for V12 and V34 from 235 to 245 seconds and 235 to 255 seconds on downleg. Positive dust layer from 239 to 247 seconds, negative dust bump from 247 to 248 seconds. Purple trace is upleg, blue is downleg. Example of 100Hz noise present on all efield channels, even V1s. FTP probe sweep frequency is 115 Hz.
Red part is high gain mode, blue areas are low gain mode.
FFT done over 10 sweeps, regions where RMS current was saturated are neglected. Vertical units are in degrees.