Author Topic: EEVblog #1178 - Build a $10 DIY EMC Probe  (Read 2671 times)

Noy and 3 Guests are viewing this topic.

Offline floobydust

  • Super Contributor
  • ***
  • Posts: 2052
  • Country: ca
Re: EEVblog #1178 - Build a $10 DIY EMC Probe
« Reply #50 on: February 12, 2019, 07:24:52 am »
It's 10 turns of #34AWG wire (0.16mm dia.) on a 1.5mm form, like a toothpick.
The murderous part is soldering the coax on one end, and the brass Faraday shield on the other. It was too flimsy, even with lots of epoxy.

If I was to revisit this, I would just buy a 0603 chip RF inductor and solder to it or make a slim pcb for the probe. I also was looking at adding a balun because the grounded (to spectrum analyzer) shield easily shorts to your PCB under test.
The R&S probe has an exposed, grounded bare metal tab which causes drama, sparks etc. for noobs.

A big area probe like OP, I do not find useful. Aside from finding an unshielded inductor or SMPS transformer gapped-core spewing flux, I'm usually looking at smaller things for EMC.
 

Offline joeqsmith

  • Super Contributor
  • ***
  • Posts: 4996
  • Country: us
Re: EEVblog #1178 - Build a $10 DIY EMC Probe
« Reply #51 on: February 12, 2019, 08:10:53 am »
Link to articles of the probes I handmade and use.   I use these without any sort of preamplifier.   They are good enough that I can normally isolate things to a single trace.   

https://www.eevblog.com/forum/rf-microwave/ferrite-bead-pcb-track-current-probe/msg1723385/#msg1723385
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline wilfred

  • Frequent Contributor
  • **
  • Posts: 391
  • Country: au
Re: EEVblog #1178 - Build a $10 DIY EMC Probe
« Reply #52 on: Yesterday at 11:34:39 am »
I don't have a multi $1,000's spectrum analyser but I do have a Digilent Analog Discovery. Could you make meaningful measurements about a circuit with such limitations? Or with some other inexpensive device. One question I had was could you measure bypass effectiveness and therefore evaluate changes/improvements where needed? Even if only on a single or double layer board.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf