New affordable EMC probe set at a bargain price - From Ariel Rocholl's lab

[Codemonkey]

Thanks for the explanation, i'll have to have a play with the VNA at work in the new year.

I presume you could also achieve pretty much the same result with a spectrum analyser with tracking generator ? Typically though, neither of the 2 I own (HP 8595E and ESA-L1500E) have that option fitted 

[G0HZU]

Yes, you could use a spectrum analyser and tracking gen here and get good results.

The other thing is that most people probably don't 'need' to make the classic (screened) H field probes from semi rigid cable. You can get fairly good results just using an open loop of wire. I have a boxful of various RF probes and sniffers here and one of my favourites is nothing more than a 'square' 2.5cm loop (2.5cm measured diagonally from corner to corner like a TV) made from some enamelled copper wire that is connected to some semi rigid cable as a loop connection across the inner and outer of the coax. You don't need to use semi rigid cable here either as ordinary cable will do but it won't be as stiff to hold as semi rigid cable so you lose the 'wand' feel to it all. This makes a quick and cheap H field probe.

The E field probe is just a regular bit of coax with just a few mm of the centre peeping out. So you could make both of these probes in a few minutes for next to no cost. Make several of the square H field loop variety in several sizes and you can do a lot of useful work. It's not going to be quite as good as the real thing but still a lot better than nothing

[Fraser]

UPDATE

Ariel has just uploaded an updated datasheet for the EMC antenna set. Coupling plots have been added.

http://j3.rf-explorer.com/download/docs/RF%20Explorer%20NF%20Antenna%20Kit%20datasheet.pdf

My set arrived last week but I have yet to have a chance to play with it. Looks well made though.

Fraser

[cdev]

Do you use it with ferrite beads on the coax?

( to decouple the coax from the loop. ) Thats what I always use.


Quote from: G0HZU on 2016-12-29, 14:40:21

Yes, you could use a spectrum analyser and tracking gen here and get good results.

The other thing is that most people probably don't 'need' to make the classic (screened) H field probes from semi rigid cable. You can get fairly good results just using an open loop of wire. I have a boxful of various RF probes and sniffers here and one of my favourites is nothing more than a 'square' 2.5cm loop (2.5cm measured diagonally from corner to corner like a TV) made from some enamelled copper wire that is connected to some semi rigid cable as a loop connection across the inner and outer of the coax. You don't need to use semi rigid cable here either as ordinary cable will do but it won't be as stiff to hold as semi rigid cable so you lose the 'wand' feel to it all. This makes a quick and cheap H field probe.

The E field probe is just a regular bit of coax with just a few mm of the centre peeping out. So you could make both of these probes in a few minutes for next to no cost. Make several of the square H field loop variety in several sizes and you can do a lot of useful work. It's not going to be quite as good as the real thing but still a lot better than nothing

[G0HZU]

Do you use it with ferrite beads on the coax?

Sometimes I play with small ferrite clamps on the coax but usually I just use the probe and my hand seems to do a similar job.

I've now managed to get hold of the right type of semi rigid cable to make a really nice (balanced) H field probe here at home. I'm hoping for more bandwidth and maybe better performance all round. But my existing H field probes are already quite good.

It would be nice to see some formal testing of the various EMC probes on offer from various suppliers. I've seen several videos where the probes get waved over circuit boards but no real performance testing. I'm still not convinced about the PCB based ones on this thread. They are probably fine for sniffing for interference but the lumpy response plots look suspicious to me. I'm not convinced they will have decent rejection of the E field over the operating bandwidth for example.

[cdev]

Perhaps a slightly different situation but check out youtube user SM5BSZ' s videos entitled "sensors"

[borjam]

I just noticed that the probe set is discounted now: $72.

I ordered it, a nice match for my RF explorer stable.

[HighVoltage]

A few years ago, I bought a set of 4 probes by BEEHIVE.
They have been working very well.
$ 295 for the set.

https://www.beehive-electronics.com/datasheets/100SeriesDatasheetCurrent.pdf