Test Equipment Anonymous (TEA) group therapy thread

[factory]

Just pulled all the 47 ohm resistors out of the HP counter. Carbon comp 5%. They're all above 56 ohms now 

and that is why i never bought a desoldering station.  bd will soon have a boat load of naked boards.

LMAO you're not wrong.

I can strip something of all the useful bits in 1/50th of the time now 

Until the thing starts playing up with worn tips, blockages and vacuum leaks from bad seals.
Actually the last one is starting to piss me off with the later Pace de-soldering irons, the front seal seems to wear out far too quickly, due to the flared tip design and it took many months to get a replacement, they ain't cheap either. 

Also my work colleague has managed to bugger up the older version, by not looking after it and running it at max power (500°C ish)  , problem is the older seal is not sold in the UK and CPC/Farnell only had one heater assembly available when I looked last week, quite frankly I can't be arsed with sorting it out. 

David

[Cerebus]

Despite Cymaphore's reservations about the Nano-Fits I think I'll give them a try. They're reasonably cheap (the headers are in the 80p - £1.50 range for the sizes I need), reasonably skookum and a better fit for what I'm doing and how I'm trying to do it than anyone else has suggested.

I have to admit may opinion is based on production line experience in our manufacturing. Very high number of crimps done by assembly operators.

For the molex contacts we had a lot more faulty parts than average and I had to put a couple of additional procedures for them in place to ensure the same level of quality than with other contacts.

So based on procedures, processing time and faults it is a much more expensive and less favorable contact from my point of view. High production numbers shift priorities, things have to be repeatable reliable even in the hands of non-engineers.

If an engineer carefully creates a hand full of crimps, it's probably much less problematic in comparison.

I did suspect it might be telling that Molex sell lengths of cable with a female crimp already crimped in place. I haven't looked up the price on those yet but they might be a way of avoiding some of the pain/drawbacks. However they come only in Henry Ford's favourite colour (black), so either concentration during assembly is called for, or being good with a pin/socket extracting tool.

Terminating wires with crimps is either one of my favourite things, or one of my most hated tasks, depending on how good the tools, terminals and wires are. A good crimp is a highly satisfying thing, a bad one nags at your soul.

[Specmaster]

Yeah, those transistor kits are good, I got myself one of those as well.

[Specmaster]

This has just popped into my inbox from one of my searches on Gumtree, anyone here interested?
https://www.gumtree.com/p/other-household-goods/avo-meters/1412009781

Edit the same seller also has this

[Cerebus]

I thought the whole point, the existential reason, of the adaptable box was to allow you to hide a horrible mess and make the job look tidy (and keep it vaguely safe if you use a metal one and can be arsed to earth bond it). 

In this particular instance, that joint box was part of a new install of a fire alarm. For those that are not aware, it's pretty much considered to be the very worst practice to make joints like this, most especially without labelling in and out on a conventional system (which this is), and really not at all on an addressable loop system, where if you have to make a joint you really should put a device there.

NB: These are not the worst pics I have, they were just the first half dozen or so most apropos of the point at hand.

The one commercial fire alarm install I've had to do was 100% done in red sheathed MICC (Actual Pyrotenax^TM branded). It was for a public performance licensed venue with the London Fire Brigade inspecting it on completion. You do not argue with those guys, you do it right first time or you don't get your license and have to wait 3 or 6 months for it to be reconsidered. In some respects it was a great job, because you could resist any penny pinching or corner cutting by saying "Ask someone who knows what the LFB's response to doing that will be". By the second or third time you're having this conversation you stop being micromanaged and get left to get on with the job.

[mnementh]

All these people being really anal about tidy wiring...   

If you think that’s bad you want to spend ten minutes looking at some of the numb skulled criminality I see in software. The whole world is built on shit and straw lobbed unceremoniously at a problem until it crushes or stinks it away. 

...aaaand now we've gone recursive. 

Too damn accurate... (Modern software development)https://twitter.com/i/status/1291608921279328261

There's a xkcd for that...

mnem
Actually, more than one...   

   

mnem
Oh, what the hell... may as well go for the Trifecta:

[Cymaphore]

I did suspect it might be telling that Molex sell lengths of cable with a female crimp already crimped in place. I haven't looked up the price on those yet but they might be a way of avoiding some of the pain/drawbacks. However they come only in Henry Ford's favourite colour (black), so either concentration during assembly is called for, or being good with a pin/socket extracting tool.

Terminating wires with crimps is either one of my favourite things, or one of my most hated tasks, depending on how good the tools, terminals and wires are. A good crimp is a highly satisfying thing, a bad one nags at your soul.

If you want to do it yourself and it's only a low number of pices in a non-SIL-area: Crimp carefully, Make a decent bend and pull test on the crimp afterwards, Test it using a low-ohm tester or by passing 200 mA to 1000 mA by it, measuring the voltage drop. Ohms law will "well enough" tell you if the crimping killed most the conductor wires or not if you compare them all. Before inserting it make sure the holding spring is at a good angle. Otherwise the counterpart pin can push it out of the housing again without much visual indication when plugging it in. You can bend the holding spring out using a sharp probe tip, but be carefull to not make it break off, it notoriously likes to do that on the very last contact after all the others are already inserted into the housing.

One collegue also believes in soldering the pin after crimping (for one off lab prototypes only), but I don't have that level of trust, the solder notoriously gets into the contact and makes plugging impossible.

If you make a couple of training crimps to get a feeling for it, it's doable and you don't have to spend money on overpriced pre-fabricated conductors that force you to use unfavourable colors and wire gauges.

[mansaxel]

Despite Cymaphore's reservations about the Nano-Fits I think I'll give them a try. They're reasonably cheap (the headers are in the 80p - £1.50 range for the sizes I need), reasonably skookum and a better fit for what I'm doing and how I'm trying to do it than anyone else has suggested.

Fair enough. You want D subs for external connections and soldered only cup pins on board as mentioned earlier with the looms strapped down then. You can have reliable and permanent but not reliable and not permanent.

In the hand- and headsets for Clansman radios, there are PCB pins that accept small circular cable connectors, like in this pic:

http://vvv.besserwisser.org/Public/Bilder/telerep.jpg

(It's http-only -- thus wont work in IMG tags -- and I CBA to upload it when it's already available, deal with it  )

They're maybe not compact, but quite sturdy. TE makes them, see page 22 ff in the linked PDF. Mouser stocks them. Quite compatible to laced loom construction where it meets PCB. My Studer mixing desk also is chock full of them -- they're used for programming things like pre-fader/post-fader taps et c.

[Cerebus]

I did suspect it might be telling that Molex sell lengths of cable with a female crimp already crimped in place. I haven't looked up the price on those yet but they might be a way of avoiding some of the pain/drawbacks. However they come only in Henry Ford's favourite colour (black), so either concentration during assembly is called for, or being good with a pin/socket extracting tool.

Terminating wires with crimps is either one of my favourite things, or one of my most hated tasks, depending on how good the tools, terminals and wires are. A good crimp is a highly satisfying thing, a bad one nags at your soul.

If you want to do it yourself and it's only a low number of pices in a non-SIL-area: Crimp carefully, Make a decent bend and pull test on the crimp afterwards, Test it using a low-ohm tester or by passing 200 mA to 1000 mA by it, measuring the voltage drop. Ohms law will "well enough" tell you if the crimping killed most the conductor wires or not if you compare them all. Before inserting it make sure the holding spring is at a good angle. Otherwise the counterpart pin can push it out of the housing again without much visual indication when plugging it in. You can bend the holding spring out using a sharp probe tip, but be carefull to not make it break off, it notoriously likes to do that on the very last contact after all the others are already inserted into the housing.

One collegue also believes in soldering the pin after crimping (for one off lab prototypes only), but I don't have that level of trust, the solder notoriously gets into the contact and makes plugging impossible.

If you make a couple of training crimps to get a feeling for it, it's doable and you don't have to spend money on overpriced pre-fabricated conductors that force you to use unfavourable colors and wire gauges.

Thanks for the tips but I've probably crimped more pins than you've had hot dinners. 

In fact thinking about the number of telco racks I cabled back in the PDH days I'm sure that I've crimped more coax connectors than I've had hot dinners.

[Cymaphore]

Thanks for the tips but I've probably crimped more pins than you've had hot dinners. 

In fact thinking about the number of telco racks I cabled back in the PDH days I'm sure that I've crimped more coax connectors than I've had hot dinners.

Sorry, if I don't know the background I rather tell the whole story and risk getting a smack on my neck for telling the obvious. You should see my checklists. The only thing missing is "breathe in, breathe out, repeat" ;-)

[mnementh]

Thanks for the tips but I've probably crimped more pins than you've had hot dinners. 

In fact thinking about the number of telco racks I cabled back in the PDH days I'm sure that I've crimped more coax connectors than I've had hot dinners.

Then why the reluctance to use JST-XH? They're a known quantity, and hard to fuck up. Or is it the fact of only having detent retention, not having a latch? Did I miss that?

mnem
*toddles off to search for furnace filters*

[mnementh]

Thanks for the tips but I've probably crimped more pins than you've had hot dinners. 

In fact thinking about the number of telco racks I cabled back in the PDH days I'm sure that I've crimped more coax connectors than I've had hot dinners.

Sorry, if I don't know the background I rather tell the whole story and risk getting a smack on my neck for telling the obvious. You should see my checklists. The only thing missing is "breathe in, breathe out, repeat" ;-)

You forgot you need to go pee. 

mnem
it's okay... we'll wait.

[Cerebus]

Thanks for the tips but I've probably crimped more pins than you've had hot dinners. 

In fact thinking about the number of telco racks I cabled back in the PDH days I'm sure that I've crimped more coax connectors than I've had hot dinners.

Then why the reluctance to use JST-XH? They're a known quantity, and hard to fuck up. Or is it the fact of only having detent retention, not having a latch? Did I miss that?

mnem
*toddles off to search for furnace filters*

There's no reluctance to using a crimp connector, the reluctance is to using a crappy crimp connector.

Header pins are easy to damage.

Header and receptacle are hard to align when inserting, almost impossible to insert blind.

A remarkably small quantity of "brute force and ignorance" needs to be applied while inserting the receptacle the wrong way around to damage or destroy the whole connector.

Pin and socket alignment is haphazard, not positively aligned.

Receptacle is hard to grip when extracting. There's only 3mm of receptacle exposed and the bit you grip is < 1mm tall and is the same width as the shroud. Fine perhaps for a Japanese woman's fingers, not for mine, BD would be well fucked. You end up gripping the shroud with more force than the receptacle - you're trying to pull the header out of the solder rather than pulling on the receptacle.

Extraction force is relatively high for the type of connector.

They turn into a pile of slag if you get hot air anywhere near them - not a great idea on an SMD board you might need to rework.

Actual crimp contact area with cable is less than 1.5mm long and way too short widthways to reliably wrap the whole wire bundle.

I really can't think of anything good to say about them other than they're cheap and ubiquitous.

[Specmaster]

Thanks for the tips but I've probably crimped more pins than you've had hot dinners. 

In fact thinking about the number of telco racks I cabled back in the PDH days I'm sure that I've crimped more coax connectors than I've had hot dinners.

Sorry, if I don't know the background I rather tell the whole story and risk getting a smack on my neck for telling the obvious. You should see my checklists. The only thing missing is "breathe in, breathe out, repeat" ;-)

You forgot you need to go pee. 

mnem
it's okay... we'll wait.

Up a rope 

[med6753]

Yeah, those transistor kits are good, I got myself one of those as well.

I would go with the cheap kits if I could. But in this case won't work. The 2N3119 are Silicon TO-5 cased devices.

[Specmaster]

Thanks for the tips but I've probably crimped more pins than you've had hot dinners. 

In fact thinking about the number of telco racks I cabled back in the PDH days I'm sure that I've crimped more coax connectors than I've had hot dinners.

Then why the reluctance to use JST-XH? They're a known quantity, and hard to fuck up. Or is it the fact of only having detent retention, not having a latch? Did I miss that?

mnem
*toddles off to search for furnace filters*

There's no reluctance to using a crimp connector, the reluctance is to using a crappy crimp connector.

Header pins are easy to damage.

Header and receptacle are hard to align when inserting, almost impossible to insert blind.

A remarkably small quantity of "brute force and ignorance" needs to be applied while inserting the receptacle the wrong way around to damage or destroy the whole connector.

Pin and socket alignment is haphazard, not positively aligned.

Receptacle is hard to grip when extracting. There's only 3mm of receptacle exposed and the bit you grip is < 1mm tall and is the same width as the shroud. Fine perhaps for a Japanese woman's fingers, not for mine, BD would be well fucked. You end up gripping the shroud with more force than the receptacle - you're trying to pull the header out of the solder rather than pulling on the receptacle.

Extraction force is relatively high for the type of connector.

They turn into a pile of slag if you get hot air anywhere near them - not a great idea on an SMD board you might need to rework.

Actual crimp contact area with cable is less than 1.5mm long and way too short widthways to reliably wrap the whole wire bundle.

I really can't think of anything good to say about them other than they're cheap and ubiquitous.

With my huge mits I'd be fucked as well, I need a XXL glove 

[mnementh]

Thanks for the tips but I've probably crimped more pins than you've had hot dinners. 

In fact thinking about the number of telco racks I cabled back in the PDH days I'm sure that I've crimped more coax connectors than I've had hot dinners.

Then why the reluctance to use JST-XH? They're a known quantity, and hard to fuck up. Or is it the fact of only having detent retention, not having a latch? Did I miss that?

mnem
*toddles off to search for furnace filters*

There's no reluctance to using a crimp connector, the reluctance is to using a crappy crimp connector.

Header pins are easy to damage.

Header and receptacle are hard to align when inserting, almost impossible to insert blind.

A remarkably small quantity of "brute force and ignorance" needs to be applied while inserting the receptacle the wrong way around to damage or destroy the whole connector.

Pin and socket alignment is haphazard, not positively aligned.

Receptacle is hard to grip when extracting. There's only 3mm of receptacle exposed and the bit you grip is < 1mm tall and is the same width as the shroud. Fine perhaps for a Japanese woman's fingers, not for mine, BD would be well fucked. You end up gripping the shroud with more force than the receptacle - you're trying to pull the header out of the solder rather than pulling on the receptacle.

Extraction force is relatively high for the type of connector.

They turn into a pile of slag if you get hot air anywhere near them - not a great idea on an SMD board you might need to rework.

Actual crimp contact area with cable is less than 1.5mm long and way too short widthways to reliably wrap the whole wire bundle.

I really can't think of anything good to say about them other than they're cheap and ubiquitous.

So when you said they were "loathed in here"... you were including yourself in that, but also trying to look at it from without at the same time...? 

I don't know how to answer that except to respond from experience with them I didn't really have a choice aboot.

I didn't say anything aboot crimp connectors in general; I was talking aboot JST-XH in particular. I know there are lots of cases where crimped cables simply are better, provided the crimping is done correctly. For making lots of connections, they are the only way to get through some projects without losing your mind from the drudgery of soldering a gazillion tiny connectors. You get to a point where it is likelier to fuck something up when soldering, and that has to be considered too.

I've literally been using them for decades in my RC gear; partly because everything comes with them, and changing to another connector would void any chance of warranty, but also because they get the job done. They are ubiquitous for a reason and they hold up much better in real world use under repeated mating cycles than they should. 

Nobody here has digits bigger or fatter than those on my big old hamhands; I handle the finished product without problem, as well as assembling them. Quite frankly, I prefer working with the crimps on these to those for DuPont connectors; they're easier to get in the crimper straight, and they're not nearly so finicky aboot an oversized wire.

If you need to solder near them on a PCB, the entire shroud can be slid up off the pins; sometimes this is a weakness as I have pulled the damned thing off a few times unintentionally. I will agree that it takes some care to not destroy them taking them apart and putting back together when they are new and tight, but if you do take care they still make reliable contact even after they work in.

You are making a choice for something that doesn't have to match a de facto standard as is the case with balance connectors, so I get wanting to go for something better. But for putting a lot of moderate current capacity connectors in a small footprint on a PCB, they're pretty hard to beat without getting into stuff so small you need to handle the bits with a magnifier and hemostats. 

But hey... you've probably made more such connectors than I've seen (rare enough that I can say that; usially it's me saying it to someone else ), so I'll defer to your superior experience.

It's just that IME, they aren't that horrible. I'd rather work with them than almost anything FPC or insulation-displacement, for example.

mnem
*toddles off to make some more wrong connectors*

[Cerebus]

[Much snipped for everyone's sanity...]

So when you said they were "loathed in here"... you were including yourself in that, but also trying to look at it from without at the same time...? 

No, I believe said "loathed here" speaking merely for myself.

I don't know how to answer that except to respond from experience with them I didn't really have a choice aboot.

I didn't say anything aboot crimp connectors in general; I was talking aboot JST-XH in particular.

I talked about having done lots of crimping, which you quoted, and then you said...

Then why the reluctance to use JST-XH?

The "then" being a connector, a "consequently", I read that as you thinking that my objection to JST-XHs was because they are crimped.

I know there are lots of cases where crimped cables simply are better, provided the crimping is done correctly. For making lots of connections, they are the only way to get through some projects without losing your mind from the drudgery of soldering a gazillion tiny connectors. You get to a point where it is likelier to fuck something up when soldering, and that has to be considered too.

I've literally been using them for decades in my RC gear; partly because everything comes with them, and changing to another connector would void any chance of warranty, but also because they get the job done. They are ubiquitous for a reason and they hold up much better in real world use under repeated mating cycles than they should. 

Nobody here has digits bigger or fatter than those on my big old hamhands; I handle the finished product without problem, as well as assembling them. Quite frankly, I prefer working with the crimps on these to those for DuPont connectors; they're easier to get in the crimper straight, and they're not nearly so finicky aboot an oversized wire.

If you need to solder near them on a PCB, the entire shroud can be slid up off the pins; sometimes this is a weakness as I have pulled the damned thing off a few times unintentionally. I will agree that it takes some care to not destroy them taking them apart and putting back together when they are new and tight, but if you do take care they still make reliable contact even after they work in.

You are making a choice for something that doesn't have to match a de facto standard as is the case with balance connectors, so I get wanting to go for something better. But for putting a lot of moderate current capacity connectors in a small footprint on a PCB, they're pretty hard to beat without getting into stuff so small you need to handle the bits with a magnifier and hemostats. 

But hey... you've probably made more such connectors than I've seen (rare enough that I can say that; usially it's me saying it to someone else ), so I'll defer to your superior experience.

It's just that IME, they aren't that horrible. I'd rather work with them than almost anything FPC or insulation-displacement, for example.

mnem
*toddles off to make some more wrong connectors*

My suspicion is that you find them less troublesome than I do because you get to use them on nice accessible things - dangling off battery packs or up in the open. My bias against them on an operational basis is running up against them in already constructed things made by other people with them placed in less accessible places - next to the edge of a case, or where you are having to reach around or under something to get to them. I find them almost impossible to manipulate reliably under those circumstances and I've heard that opinion voiced more than once by other people, so I'm not alone in thinking that. There was a thread a few weeks back about making tools to grip the receptacle. I think the fact that several people felt the need for a tool to use to disconnect them speaks volumes to my mind.

I got a mixed box of assorted JST-XH headers and receptacles a while back simply because I keep encountering things with them already installed and wanted some to hand for repair and adaptation. Assessing the design wasn't really on my mind when ordering them as repair stock, for that purpose it was merely enough that they fit. At the time of getting them I though that I'd probably end up using some for new construction but once I had them and had taken a good look up close and personal I changed my mind.

I can definitely agree about one thing, they are easier to crimp reliably than DuPont connectors. But then DuPont connectors, useful as they are, are the world's worst connector. Perhaps the original, genuine made by DuPont article is better, but what passes for 'DuPont' from most sources are horrible.

[beanflying]

Outside my budget but 60V 120A module fitted and was recently in Calibration if anyone is in the market for one. eBay auction: #294326799480

[bitseeker]

...
WOW !! Thanks for that !! A one liner cpomment I could easily have missed when skimming 2+ pages worth of TEA ! Glad I took the time to read each and every comment ! 
...

Yes, reading this thread can be a challenge itself. Things go by pretty fast. Zoooom!

You got some experiences in this respect? 

Who me? Nah, couldn't be.

[bitseeker]

Since the seller countered my offer, I asked for a photo of the bottom.

(Attachment Link)

Those little feet don't fit the mounting holes in the case bottom (which I've seen another example of lately) and probably wouldn't hold a tilting bail like on Martin's 8300A. So, I suspect it may have been a revision.

Yeah, those DEFINITELY aren’t the original feet.  I’m sure it had something along the lines of the HP feet, squarish and likely with some sort of overhang to grip the top of another instrument beneath it as the HP ones do.  Though I suppose aftermarket feet are better than the usual no feet you see on so many things...

-Pat

Correct Fluke feet, taken from an 8505A.

Wow, those are different again. And the third style of tilting bail I've seen so far.

[bitseeker]

My feet are gray

Yeah, those are like the ones on my 8100A.

[bitseeker]

Haha, yeah I've been seeking bits for "da man". Not many bits for myself. However, I did snag

1. a used Siglent SSA3021X (not Plus)

2. a used Fluke 23 Series II

both in like-new condition. The DMM included all the original docs, holster, and leads as well as its screen protector. Apparently, it wasn't used much, which also meant no battery schmoo inside.

Hey that's cool stuff. But don't be so afraid of it getting dirty that you leave it covered all the time. You can touch it! 

ROFLMAO! I'm just sharing it like it is. No masks, no makeup.

[bitseeker]

This job would have been hell without this and I've avoided a lot of repairs before. Not only that I don't have to necessarily snip the parts out now to safely desolder which makes debugging and lifting leads cheaper.

I am impressed. Money well spent 

Indeed. I've got an ancient Pace MP-1 and I wouldn't be without it to get ICs out. I've even desoldered power diodes from a UPS PCB with solder-laden traces using that little guy. An oldie, but a goody.

[bitseeker]

Saw a Fluke 8300A this weekend. While I was negotiating a price, someone paid full price for it. Ah, well.

Anyone from here grab it? It's got nice options.

Sorry, man.  It popped up in my search this morning, I looked and saw it was well optioned and jumped on it as they’re relatively rare and usually being being sold by people who want a couple of hundred bucks for one in unknown condition.  Have the manual that I bought a few years back when I’d bought one from the bay that the seller later cancelled because it "failed test" (it had been listed as 'for parts or repair'), and when I pointed that out and said I didn’t expect it to work was then told it had already been discarded.  I was pretty pissed about that.

-Pat

Hey, no problem. I'm happy you got it and not some dismantler, especially since it had all the requisite options. Of course, I look forward to learning more about it when you receive it. I'm especially curious if the round feet are original. It doesn't have a tilting bail, like many I've seen, but I'm not sure if that's original either. Since it has an IEC power socket, it seems to be a later version.

At least I can enjoy it vicariously here.

I’ll be sure to post pics of it.  The guy’s a quick shipper - FedEx has it in Kennesaw, GA already.  I’m not up on Fluke feet, but I guess will learn in a few days.

-Pat

If not, I may be able to help with something printed. Let us know.

mnem
 

bean made a version of vintage Fluke feet https://www.eevblog.com/forum/testgear/replacement-knobs-feet-and-fittings-for-test-equipment/msg2502039/#msg2502039