Test Equipment Anonymous (TEA) group therapy thread

[Mr. Scram]

Added to list of reasons not to buy test gear from Oz: Hidden death spiders!

Oven finally sorted. Chucked it in the hole earlier. Didn't hire a sparky this time as they're all shit. Electricity is safer in my hands than theirs.

Do you list misanthropy as a skill on your resume or is it just an out of hand hobby?

[bd139]

Do you list misanthropy as a skill on your resume or is it just an out of hand hobby?

Both!

[Specmaster]

Haha judging by the size of the beast, once he#s in, he'd never come out alive unless you opened it up so, leave the kit unopened, if it fails, toss it, deterrent neutralised 

'Size does not matter' is for once not a lie when you meet this fellow. The fact that Australians take note of it should be a hint.

I'm only too aware of the Vemonous Australian spiders many of which can give a fatal bite if not treated quickly, I have relations in Brisbane. I mentioned its size as it looked to be a big bugger and as such would need a large hole to escape said equipment (assuming it did not have that) and maybe by the time the equipment needs opening it would be dead 

[bitseeker]

Added to list of reasons not to buy test gear from Oz: Hidden death spiders!

Fumigate package prior to unboxing...and maybe after unboxing too, for good measure.

[Mr. Scram]

I'm looking to buy Kelvin clips of a respectable make without breaking the bank. I can't imagine these needing to cost as much as a proper multimeter. Any hints or suggestions?

[bd139]

I've not seen any that aren't shit for a reasonable amount of money. Adafruit sell the clips on their own for $2.50 a pop but I can't vouch for the quality. Probably just Chinese rebrands: https://www.adafruit.com/product/3313

Interesting excuse to buy another scope. I just blew the shit out of another IRF510. That's all 5 now gone up in smoke and I've had to order some more. Investigation points to massive overshoot on the load transformer on my single ended stage when you key the transmitter. I can just about make it out on the 465 if I turn all the lights out but it's very faint and is hitting 95 volts! I reckon it's overshooting past Vds(max) to over 100v but the scope isn't fast enough to see it. This slowly kills the IRF510 gate oxide layer and then it conducts and self destructs, violently.

Fun fun fun - off to ebay

[Mr. Scram]

I've not seen any that aren't shit for a reasonable amount of money. Adafruit sell the clips on their own for $2.50 a pop but I can't vouch for the quality. Probably just Chinese rebrands: https://www.adafruit.com/product/3313

Interesting excuse to buy another scope. I just blew the shit out of another IRF510. That's all 5 now gone up in smoke and I've had to order some more. Investigation points to massive overshoot on the load transformer on my single ended stage when you key the transmitter. I can just about make it out on the 465 if I turn all the lights out but it's very faint and is hitting 95 volts! I reckon it's overshooting past Vds(max) to over 100v but the scope isn't fast enough to see it. This slowly kills the IRF510 gate oxide layer and then it conducts and self destructs, violently.

Fun fun fun - off to ebay

I'm willing to spend up to $50, but the good ones are over double that and the others I don't quite trust. There has to be a reasonable solution?

[GreyWoolfe]

I've not seen any that aren't shit for a reasonable amount of money. Adafruit sell the clips on their own for $2.50 a pop but I can't vouch for the quality. Probably just Chinese rebrands: https://www.adafruit.com/product/3313

Interesting excuse to buy another scope. I just blew the shit out of another IRF510. That's all 5 now gone up in smoke and I've had to order some more. Investigation points to massive overshoot on the load transformer on my single ended stage when you key the transmitter. I can just about make it out on the 465 if I turn all the lights out but it's very faint and is hitting 95 volts! I reckon it's overshooting past Vds(max) to over 100v but the scope isn't fast enough to see it. This slowly kills the IRF510 gate oxide layer and then it conducts and self destructs, violently.

Fun fun fun - off to ebay

I'm willing to spend up to $50, but the good ones are over double that and the others I don't quite trust. There has to be a reasonable solution?

I bought these clips, https://www.ebay.com/itm/For-Copper-Gwinstek-LCR-Kelvin-Test-Clip-Bridge-Test-Clip-Microresistivity-Clamp/252204657919?hash=item3ab891acff:g:-REAAOSwB09YJ9T5  Some banana plugs from Frankie and I have silicone test lead wire and made my own.  They seem to work well enough for me.

[BravoV]

I've not seen any that aren't shit for a reasonable amount of money. Adafruit sell the clips on their own for $2.50 a pop but I can't vouch for the quality. Probably just Chinese rebrands: https://www.adafruit.com/product/3313

Interesting excuse to buy another scope. I just blew the shit out of another IRF510. That's all 5 now gone up in smoke and I've had to order some more. Investigation points to massive overshoot on the load transformer on my single ended stage when you key the transmitter. I can just about make it out on the 465 if I turn all the lights out but it's very faint and is hitting 95 volts! I reckon it's overshooting past Vds(max) to over 100v but the scope isn't fast enough to see it. This slowly kills the IRF510 gate oxide layer and then it conducts and self destructs, violently.

Fun fun fun - off to ebay

I'm willing to spend up to $50, but the good ones are over double that and the others I don't quite trust. There has to be a reasonable solution?

I bought these clips, https://www.ebay.com/itm/For-Copper-Gwinstek-LCR-Kelvin-Test-Clip-Bridge-Test-Clip-Microresistivity-Clamp/252204657919?hash=item3ab891acff:g:-REAAOSwB09YJ9T5  Some banana plugs from Frankie and I have silicone test lead wire and made my own.  They seem to work well enough for me.

Frankie sells two types, the one for small current with sharp pins, and another one for high current, bought both types from him, but I like this one below as its less finicky and feels very solid. Its basically the clone of Mueller BU-78K, but way cheaper and quite good quality.

Mine sourced from Frankie.

[Neomys Sapiens]

I'm looking to buy Kelvin clips of a respectable make without breaking the bank. I can't imagine these needing to cost as much as a proper multimeter. Any hints or suggestions?

I think it was some discussion on this forum where someone pointed out that all the cheap ones have only rubber rings acting as springs. Also, they are not made for disassembly.
I have an idea that might work if someone has access to some specialty tools.
Use riffler files to carefully make a small depression inside of the rear legs of the clips, then insert a small compression spring. That might cure the rubber band wearout problem, if feasible.

[mnementh]

Added to list of reasons not to buy test gear from Oz: Hidden death spiders!

Oven finally sorted. Chucked it in the hole earlier. Didn't hire a sparky this time as they're all shit. Electricity is safer in my hands than theirs.

Do you list misanthropy as a skill on your resume or is it just an out of hand hobby?

Both!

Sarcasm... just another service we offer! 

I've not seen any that aren't shit for a reasonable amount of money. Adafruit sell the clips on their own for $2.50 a pop but I can't vouch for the quality. Probably just Chinese rebrands: https://www.adafruit.com/product/3313

Interesting excuse to buy another scope. I just blew the shit out of another IRF510. That's all 5 now gone up in smoke and I've had to order some more. Investigation points to massive overshoot on the load transformer on my single ended stage when you key the transmitter. I can just about make it out on the 465 if I turn all the lights out but it's very faint and is hitting 95 volts! I reckon it's overshooting past Vds(max) to over 100v but the scope isn't fast enough to see it. This slowly kills the IRF510 gate oxide layer and then it conducts and self destructs, violently.

Fun fun fun - off to ebay

This kind of ringing sounds like possibly a saturation issue...? Just a random thought...

I've not seen any that aren't shit for a reasonable amount of money. Adafruit sell the clips on their own for $2.50 a pop but I can't vouch for the quality. Probably just Chinese rebrands: https://www.adafruit.com/product/3313

(SNIP)

I'm willing to spend up to $50, but the good ones are over double that and the others I don't quite trust. There has to be a reasonable solution?

I bought these clips, https://www.ebay.com/itm/For-Copper-Gwinstek-LCR-Kelvin-Test-Clip-Bridge-Test-Clip-Microresistivity-Clamp/252204657919?hash=item3ab891acff:g:-REAAOSwB09YJ9T5  Some banana plugs from Frankie and I have silicone test lead wire and made my own.  They seem to work well enough for me.

Frankie sells two types, the one for small current with sharp pins, and another one for high current, bought both types from him, but I like this one below as its less finicky and feels very solid. Its basically the clone of Mueller BU-78K, but way cheaper and quite good quality.

Mine sourced from Frankie.

I've got some of these in grey that I've been using on my cheap 128-64 Component testers; they work well once you spend a little time fiddling with the jaws so they align right to get good bite, and the jaws are gold-plated brass/bronze, NOT ferrous. I'm using them with short silicone wires in the 18-20ga range. I did make some strips of unplated PCB to insert under the spring where those strips of 'glas mat are on the contacts; that spring lying right on that thin matting struck me as a very likely source of unintended coupling between the two sides.

I see the ones AdaFruit sells all over fleaBay for similar prices China-direct.

mnem
*Fulminating at the mind*

[BravoV]

I've got some of these in grey that I've been using on my cheap 128-64 Component testers; they work well once you spend a little time fiddling with the jaws so they align right to get good bite, and the jaws are gold-plated brass/bronze, NOT ferrous. I'm using them with short silicone wires in the 18-20ga range. I did make some strips of unplated PCB to insert under the spring where those strips of 'glas mat are on the contacts; that spring lying right on that thin matting struck me as a very likely source of unintended coupling between the two sides.

These grey Kelvin clips are quite crappy imo, used and dump them. Its the plastic parts that are so weak & inferior making lots of troubles, like scratchy hinge parts, not properly align at the tips, spring problems and etc.

Get better one like from Frankie, reviewed by one of fellow forum here -> Franky's Kelvin Clip kit

[mnementh]

Yes, those are the same ones Greywoolfe linked to a few posts above. I'm not trying to claim they aren't better quality; it's obvious they are.

But I got 3/$5 shipped on these cheapies, and considering the above caveats, they're a much better clip than the ones with rubber bands.

It certainly is easy to replace the plastic peg with a metal or nylon bushing and screws; then you have clips that are almost identical to the ones Instek sells in a set of leads for $130.

 Of course, I'm just the sort of weirdo that would have a bin full of such things. 

Cheers,

mnem
*Toddles off to ded*

[bitseeker]

It certainly is easy to replace the plastic peg with a metal or nylon bushing and screws; then you have clips that are almost identical to the ones Instek sells in a set of leads for $130.

Of course, I'm just the sort of weirdo that would have a bin full of such things. 

Unless one can afford to do TEA with all new, high-end products and accessories, having a bin full of bits and bobs is par for the course.

[Specmaster]

It certainly is easy to replace the plastic peg with a metal or nylon bushing and screws; then you have clips that are almost identical to the ones Instek sells in a set of leads for $130.

Of course, I'm just the sort of weirdo that would have a bin full of such things. 

Unless one can afford to do TEA with all new, high-end products and accessories, having a bin full of bits and bobs is par for the course.

Nice but not a lot of fun if you can afford to use new highend equipment. The fun is finding ways of making cheaper or parts from parts pile/bin work effectively.

From mobile device so predictive text might have struck again [emoji83]

[bitseeker]

Yup.

[beanflying]

In use the cheapy Chinese plastic are nicer than the oring/silicone ones on my Quadtech millohm meter. As to absolute measurements I would be buying branded gold plated for $

[Berni]

In use the cheapy Chinese plastic are nicer than the oring/silicone ones on my Quadtech millohm meter. As to absolute measurements I would be buying branded gold plated for $

I also have the gray ones for 4 terminal measurement and they are pretty nice. The jaws align well and make good contact.

I bought the whole finished probe set with the cables and banana terminals on the end, the crappy part turned out to be the bananas where the springy rotating contact part of it started to develop a bad contact with the rest of the banana terminal. I fixed it by soldering the springy part to the rest of the bananas shaft and now they work perfectly again.

[bd139]

Nice but not a lot of fun if you can afford to use new highend equipment. The fun is finding ways of making cheaper or parts from parts pile/bin work effectively.

Very true. Also to note, a lot of the new parts are ridiculously cheap. I mean crazy cheap.

I'm slightly obsessed with this at the moment. Honestly I think it's possible to get on the air with a reasonable transceiver for under £20 for CW and under £30 for SSB actually buying the parts from the UK. I've got my transmitter chain BOM down to £3 so far (BC547 osc/buffer, BC327 power control, BD139 driver [of course] and IRF510 PA to kick out 15W!) 

[Ero-Shan]

In use the cheapy Chinese plastic are nicer than the oring/silicone ones on my Quadtech millohm meter. As to absolute measurements I would be buying branded gold plated for $

My LCR meter (Tonghui) came with clips that look just like those gray ones. Until now I'm quite happy with them. As I am with the meter, actually.
It was only yesterday when I thought that I'd really like some more Kelvin clips. They're very handy for 4-wire resistance measurements.

[beanflying]

I suspect that without some very careful use of high end test gear the difference in measurements between cheap and expensive for most of us is pointless. As was mentioned a few post back the Banana jacks are more of an issue.

The Grey ones BTW are on 4mm Jacks for my Agilent while the others are on a fairly custom DIN style plug on the Quadtech so I currently have no real way of testing them electrically against each other.

Like all nuttery multiply the price x 10+ to gain maybe 1-2 percent 

[bd139]

Probably right. The only place I use 4-wire myself is power supply sense. I want the right voltage at the destination rather than the source.

[Berni]

I never made much use in sense wires on PSUs, I just use fairly thick cables to minimize the voltage drop and that's close enough, most of my PSUs are not super accurate anyway.

But i like 4 terminal measurement for resistance when i'm dealing with things of 1 Ohm and under. These kelvin clips and my keithley dmm easily measures the tiny resistance of a few mm of copper wire with great repeatability.

[mnementh]

It certainly is easy to replace the plastic peg with a metal or nylon bushing and screws; then you have clips that are almost identical to the ones Instek sells in a set of leads for $130.

Of course, I'm just the sort of weirdo that would have a bin full of such things. 

Unless one can afford to do TEA with all new, high-end products and accessories, having a bin full of bits and bobs is par for the course.

Then it wouldn't be TEA; it would be working a corporate R&D gig. I learned the hard way I'm not cut out for that environment; the neverending top-down "battle between flavors of crazy" filters down to those trenches a little too fast for my tastebuds. I don't like being trapped in a feedback loop IRL any more than I do on paper or in circuit. 

And yeah... what mechanic doesn't have a bucket of bolts under the bench; what tinkerer doesn't have bins full of leftovers and "Damifino" saved against future projects.  Not any real ones...

In use the cheapy Chinese plastic are nicer than the oring/silicone ones on my Quadtech millohm meter. As to absolute measurements I would be buying branded gold plated for $

I also have the gray ones for 4 terminal measurement and they are pretty nice. The jaws align well and make good contact.

I bought the whole finished probe set with the cables and banana terminals on the end, the crappy part turned out to be the bananas where the springy rotating contact part of it started to develop a bad contact with the rest of the banana terminal. I fixed it by soldering the springy part to the rest of the bananas shaft and now they work perfectly again.

Yeah, I got some of the o-ring ones first for my 128-64 component testers; I couldn't get them to grip any small component without deflecting, then popping and sending it peening off into the darkest recesses of my office. I threw them in a drawer and later dug them out as repair material for the wiper on a mechanical speed control.

I found, like you, that the grey ones aligned well with minimal tweaking. 




As for 4mm bananas... I've gotten away from them completely for any low-voltage test leads I make since discovering HXT battery connectors from my RC hobby. When originally introduced, you got these nice machined male bullet connectors along with the red shrouds; by their nature, it's a pretty flexible connector design and great for making polarized plugs or 4mm extension cables with decent silicone wires like these from Turnigy/HobbyKing.

But since Turnigy bought the HXT Brand, all you get now is gold-plated regular 4mm banana plugs with the garter spring contacts like they've been made for decades; they save the CNC design for their more expensive 5mm & up connectors.  The difference is right there in the specs; the original CNC design HXT connector was rated at 100A cont/140A surge while these are rated 60-80A cont/80-100A surge.

That said... the CNC bullets are still available; you just have to look around. I usually wind up buying a bag (10 pairs) of the HK HXT connectors, then going to and adding a set of PolyMax 4mm bullets just to get the male bullet for my HXTs. It's STILL cheaper than the boutique Hyperion connectors. 

The PolyMax 4mm CNC connectors are available elsewhereas well; ValueHobby has them, and you can find them on fleaBay. Shop around; they should cost $3-4/10 pairs plus shipping.



HK also carries some very nice, high-precision CNC 4mm bullet connectors that have been niggling at the back of my mind ever since I first saw them months ago; to make some really high-quality low-loss sets of extra-long test and jumper leads using these and their silicone wires and potting the solder joints with silicone. Their 14-12ga wires have really nice, thick silicone jackets around 1.5mm thick; not double layer but I'd love to know what voltage they're safe to. It annoys me that they don't list that rating; probably the reason I haven't pushed the project to the front burner yet.

On most of my higher-powered quadcopters I've been migrating away from the HXT connectors; the yellow AMASS Anti-Arc XT90s seen here use the same CNC bullet inside, but on the female they have a bleeder resistor connected to a slip ring that contacts before the plug fully seats. This precharges the several hundred uF of ceramic and electrolytic capacitors found in modern high-frequency/high-current ESCs, (high performance H-gate brushless motor drivers) of which you typically have 4-6 in parallel. Arcing is a serious problem on these; 6S (25.2V peak) ultra-low IR LiPo packs capable of delivering 200A or more are common nowadays; that's a lot of juice. Those XT90s more expensive, but worth it in this application.

I suspect that without some very careful use of high end test gear the difference in measurements between cheap and expensive for most of us is pointless. As was mentioned a few post back the Banana jacks are more of an issue.

The Grey ones BTW are on 4mm Jacks for my Agilent while the others are on a fairly custom DIN style plug on the Quadtech so I currently have no real way of testing them electrically against each other.

Like all nuttery multiply the price x 10+ to gain maybe 1-2 percent. 

I think that's the nutshell right there. 



Cheers,

mnem
*Juicy*

[bd139]

I never made much use in sense wires on PSUs, I just use fairly thick cables to minimize the voltage drop and that's close enough, most of my PSUs are not super accurate anyway.

But i like 4 terminal measurement for resistance when i'm dealing with things of 1 Ohm and under. These kelvin clips and my keithley dmm easily measures the tiny resistance of a few mm of copper wire with great repeatability.

I just go "ooh that's under an ohm". Much cheaper