1. spectrum amplitude (dBV)
Noise Crash Cart:
Tektronix oscilloscope with FFT
Protek 3290 RF Spectrum Analyzer MHz
Dell Laptop all can run on batteries
isolation transformer
AC current clamp (ground loop current detection)
Ground tester
Examples:
RF spectra reveal several
radio, TV, mobile frequencies
but also a wide band emission
from 1-10 MHz in C-120 area
AC ground loop currents in several system
from the worst: 60 Hz+ harmonics (top)
to a very good (bottom) 1 4 2 1 5 2 3 1 5 4 3 1 6
I (mA)
spectrum amplitude (dBV) 3 2 2 3 4 6 5 4 5
time (ms)
frequency (MHz)