Pocket EMC Debug Probe V2

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.

 

 

Introduction

A short introduction to near field probes and their uses.

 

Assembly Guide

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)

Sourcing SMA edge mount female connectors (RS, eBay)

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)

 

Usage

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