This is a work in progress guide for the assembly and use of the Version 2 “Pocket EMC Debug Probe” from Unit 3 Compliance.
Whilst this page is being written, you can also refer to this page for the previous version which has much of the information that you need.
A short introduction to near field probes and their uses.
Components required (0805 resistors, R1 = 470R, R2 = 10k, gives 450 ohm parallel combination, required for the 10:1 into a 50 ohm input, capacitor 1nF, C0G/NPO dielectric, 50V)
Recommendations for the probing pin (socket strip or a bit of wire)
Suitable ferrite cores for the current transformer
90 degree options for the B-field loop probe and E-field capacitive probe (on E-field probe snap off – scrape copper on each side of slot before you snap off the end to enable soldering)
Narrow down emissions from a PCB by scanning over the surface and looking for noisy traces
Don’t just use the B-field probe, the E-field probe is just as important. Both will respond differently.
Use the current probe attachment to check for noisy cables
Narrow down to individual traces using the high bandwidth probe