Can't find an old thread: Inexpensive E & H near-field probes?

[cvanc]

I know there was a good discussion on EEVBlog about this but my search mojo is weak tonight.  Can anyone point the way?  Thanks.

[tautech]

I know there was a good discussion on EEVBlog about this but my search mojo is weak tonight.  Can anyone point the way?  Thanks.

I sometimes struggle on that same one too !

But just remember it was started by member Fraser so check his profile and look in his Topics to find it. 

[hendorog]

This one came to my mind due to loxodes being one of the open VNA chaps.

https://www.eevblog.com/forum/rf-microwave/open-hardware-near-field-probes/

https://github.com/loxodes/emc_tools

[Brumby]

Is this it?

https://www.eevblog.com/forum/testgear/new-affordable-emc-probe-set-at-a-bargain-price-from-ariel-rocholl's-lab/

[Kean]

I think the cheapest ones are the RF Explorer near field probes from Seeed (unless you make them yourself)
https://www.seeedstudio.com/RF-Explorer-Near-Field-Antenna-Kit-p-2784.html

There are also a nice set from Tekbox
https://emcsupplies.com/collections/near-field-probes/products/tekbox-emc-near-field-probe-set-tbps01

I have both sets.  The RF explorer ones are quite a bit smaller/shorter, but the Tekbox ones have good handles to help keep your hands away from the PCB you're measuring.

Tekbox also have some nice wideband RF amplifiers, which you will possibly need to make the most of these probes.

[Gandalf_Sr]

I have a set of these beehive ones. The ones linked to from Fraser's post on seeed studio look nice for $98. 

Can anyone tell us how these 2 sets of probes compare?

[Kean]

I have a set of these beehive ones. The ones linked to from Fraser's post on seeed studio look nice for $98. 

Can anyone tell us how these 2 sets of probes compare?

I almost bought the Beehive ones, but then Tekbox brought out theirs at a lower price.  I think Beehive may have dropped their price a bit since then.

Ken Wyatt has done a bit of a comparison here of the Beehive vs Tekbox vs R&S:
https://www.edn.com/electronics-blogs/the-emc-blog/4440825/Review--Tekbox-Near-Field-Probes

[EE-digger]

The Beehives are good.  The owner of the company is former HP/Agilent who was involved in their near field probe designs.  He is very helpful if you need information or application help.

You can also make your own and they can be quite good.  Just the right size and with good E-field rejection if you're careful, with semi-rigid coax.

The E-field probes are simply an exposed length (like 6mm for instance) of coax center with insulation.

By simply looping 0.085 center conductor back to the shield (i.e. loop diameter 0.040 - ish) I've mapped H field emissions off the top of an FPGA very precisely, fixed with self adhesive absorber.

I apologize ... did not answer the original question 

[EE-digger]

A quick look at Ken Wyatt's review led me to examine the datasheet for the 100C probe I have from Beehive, a bit upset that perhaps my probe sucked.

The 100C has a 3dB point at 50MHz for its diameter.  What Ken saw as "lack of sensitivity" is actually the first resonant point of the probe in the 300 to 600 MHz range (Beehive says 500MHz).

You need to use a probe over its specified range or understand the limitations imposed by exceeding that.

Otherwise, I love Ken Wyatt's articles