EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: michaeliv on April 05, 2016, 07:14:18 pm
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Hello,
Can anyone recommend some good not-ridiculously-priced grabbers ?
I got some Tektronix SMT SMG50 (http://www.ebay.com/itm/201263961054) which are excellent except for the part where the end that you push on is very, VERY wobbly.
I also got some Agilent / HP 5090-4833 (http://www.ebay.com/itm/Agilent-HP-5090-4833-SMT-Grabber-Kit-Pack-of-5-/272155619895) and they are decent but not as good as the tek. They don't have any wobbliness issues.
Does anyone have any feedback on these Agilent 10230-68702 (http://www.ebay.com/itm/301916682778) ? They seem high quality but also seem to have a ridiculously thick shaft.
Also how about these Tek 020-1386-00 (http://www.qservice.tv/vpasp/shopexd.asp?id=10380) - they seem to have a metal insert at the end.
What do people use other than 10c Chinese grabbers ?
Thanks!
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What do people use other than 10c Chinese grabbers ?
I like E-Z Hook http://www.digikey.com/product-detail/en/e-z-hook/XKMGRY/461-1011-ND/528232 (http://www.digikey.com/product-detail/en/e-z-hook/XKMGRY/461-1011-ND/528232) , but they are still a bit expensive. But the quality is amazing, noting wobbles at all.
And I think Agilent uses rebranded E-Z Hook with some of their devices. At least I have a few that have Agilent logo on them.
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I like E-Z Hook http://www.digikey.com/product-detail/en/e-z-hook/XKMGRY/461-1011-ND/528232 (http://www.digikey.com/product-detail/en/e-z-hook/XKMGRY/461-1011-ND/528232) , but they are still a bit expensive. But the quality is amazing, noting wobbles at all.
Those E-Z hooks look suspiciously identical to the Agilents http://www.ebay.com/itm/Agilent-HP-5090-4833-SMT-Grabber-Kit-Pack-of-5-/272155619895 (http://www.ebay.com/itm/Agilent-HP-5090-4833-SMT-Grabber-Kit-Pack-of-5-/272155619895) .
The Agilents are super sturdy as well, the only problem with them is they have a ridiculously high impedance, 35 times the ones of the Tektronix SMG50. Around 200mOhms, and that is if you manage to make a perfect connection. And I would want to use them for transferring power sometimes. Do the E-Z hook's also have a large impedance ?
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Do the E-Z hook's also have a large impedance ?
I have no idea, I've only used them for actual logic stuff. And I don't have a good way to measure that at the moment.
E-Z Hook is a legitimate product, so I'm inclined to believe that Agilent is licensing the design. But I stand to be corrected on this.
And, as I said, they have exactly the same look and feel as Agilent ones, except for the logo.
Edit: According to Uni-t UT136B, they do have 0.2 Ohm resistance when clip is hooked to a probe and anther probe touches exposed contact on the other end.
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Another vote for EZ Hook. Fry's carries (at least around here) Pomona & EZ Hook brand test clips. For most stuff the Pomona look like they are slightly higher quality, but I've never had any problems with any of EZ Hooks stuff. They aren't cheap, but cheaper than Pomona. Usually if its something I need that day I end up getting the EZ Hooks.
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Hirschmann (Micro) Kleps may be another option. They look high quality, but also not particularly cheap. The Micro is specified as 10mOhm resistance and rated for 2A.
I haven't tried these myself yet.
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According to Uni-t UT136B, they do have 0.2 Ohm resistance when clip is hooked to a probe and anther probe touches exposed contact on the other end.
Yes, then it's almost certain that the Agilent's are just rebranded E-Z hooks.
As a follow-up, I did end up getting some Tektronix 020-1386-00. They do have a metal insert at the tip which sticks out about 2mm - It is somewhat wide so it might cause shorts in tight situations. They do have low resistance ( < 10mOhm ), they don't have any flex, but the actual grabber part( tip ) is very flimsy, the worse out of all probes, similar or worse than the 10c Chinese ones. So the SMG50's look like the best option, or the Agilent / E-Z if you don't care about probe resistance.
Also, the SMG50's can be made more sturdy by inserting tape in between the part that is pushed in by your finger and the circular piece that holds it in place - there is a gap in between these two parts that causes wobbliness. After this mod they actually behave quite decently.
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Hirschmann (Micro) Kleps may be another option. They look high quality, but also not particularly cheap. The Micro is specified as 10mOhm resistance and rated for 2A.
+1 for Micro Kleps. Not perfect, but a far cry from the cheap China clips.
Pricing is about 4...5 EUR per piece. Worth the money IMHO.
Max
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Follow-up: I ended up constructing my own adapter built on a vero board.
Each channel is 1m of cable that goes into a series 330R resistor followed by a 27pF capacitor to ground.
The ground is 1m -- just 1m of cable connected directly to scope ground.
If I didn't have the resistor / capacitor, the overshoot would be ridiculous(somewhere around 2x the signal).
This is obviously not an ideal solution and will cause bad things such as decreased bandwidth, signal loading and teenage pregnancy.
Am I missing other effects that may happen ? Could the cable cause signal reflection / ringing back into the DUT ?
Thanks!
Note: The "Using probe" in the picture below is the best possible connection via probe, using the tip + ground metal cylinder directly onto the signal, no wires involved.