Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

Has anyone heard from Chris (bd) lately? 

I miss the (insert British term of endearment) cunt. 

Not a squeak ! Normally pops into Discord for a chat but didn't even do that so I'm guessing he may have found some new redhead bd140 to use all his spare time. 

I'll pop him mail and see if he's still sucking air.

Nailed it ! ^^^ 
Yep BD seems great but time poor.

Shhhh... I think that's a large part of why bd isn't in here lately; he knows he can't lay off the batshit crazy redhead jokes, and he doesn't wanna spoil it when she magically appears looking over his shoulder unnoticed for Ifni knows how long, as they always do...

mnem
It's worse than you think: they they have the ability to see through your eyes... 

Well what concerns me more is the resultant sum of the betas of this new BD140 paired with our known high beta BD139. 

High gains might have this one sticking around. 

BD reckons she owns a DMM so there's a chance he's hit the jackpot and I really hope he has. No mention of hair color .........yet ! 

Spoke with him a little while ago... he says there is some chance he might make Discord, as the MCP has to be away doing some training.

Fingers, toes, wings and tail crossed for luck; both for him making it tomorrow and his new life track!

mnem
 

[mnementh]

I am coinorhaging heavily ...

You mean as in hemorrhaging money?

Pfffft. You're spending money to make money. I've been living off my savings and inheritance for 2 years in a foreign country. That is coinorrhaging.

mnem
*dizzy from watching money go down the drain*

[mnementh]

The thing that drives PAT is insurance. Many commercial policies require portable appliance testing.
 

It is blame shifting, nothing but, at least in the degenerate form that's been described here. And, as you write, not a very successful blame management at that. When PAT became the norm in UK, some 25 years ago, IIRC, where I worked did quite a bit of import from the UK, so we kept reading about this, and concluded "someone is trying to insure themselves against stupidity."

Not even remotely successful blame-shifting. The manager responsible for organising the PAT schedule is liable, period. Said manager is also required to understand PAT regulations as well as every aspect of testing.

Wait... so you're saying that a member of management, that species world-renowned as unable to find their own arse with both hands, is expected to actually know technical regulations and technical procedures as if they were an actual technician doing actual work...?

Imagine that. 

mnem
 

[Neomys Sapiens]

.
.
These little MP1584EN-based switchers are noisy AF, but pretty damned good otherwise; I keep a few on hand, as I treat them like Lego building blocks. They will handle a 15-20V drop at 2A all day long if you stick the the PCB to a large metal mass with some silicone thermal pad. Big plus, they aren't known to fail Vin-Vout short-circuit.
.
.
mnem
Datasheet attached below for those who care. 

The mention of switcher modules and 'treat them like Lego building blocks' triggered an unwelcome reminiscence with me. Otherwise no connection, other technological era, other modules.

A major error during scavenging once comitted by me, which has severely reduced the usefulness of the parts gained.

Somewhere in my storage is a box full of switching regulator modules, which are identical except for the voltage and current programming resistors. I got them from dismantling a Philips minicomputer which I saw standing between other disposal items when driving around at night.
There are at least 15 of them, each with his own heatsink. Input and output are via 6.3mm Faston connectors. Together they formed the main PSU of this SSI/MSI-based minicomputer. So far so good.

 When I looked at them later I thought about the power supply that they made up. Typically, a massive 5V output as well as several others. And yes, as I found them there was a web of ribbon cable interconnects over them, some with wires crossed over, some with splits, some with two wires, others with more. And yes, on each of those modules is a 8-pin header. Those cables I detached and discarded immediately, as they were hindering the extraction of the modules from the sheetmetal cage they were set in. Belated I realized that with those cables I discarded any discernable information on paralleling and tracking arrangements possible with those parts. Aggravating this was the fact that I did not take any notes on their input circuit. Yes, it was unregulated DC, but was it all the same potential or not?
Those modules could have been SOOO Much More useful.
Meh.

[Neomys Sapiens]

P.S.: I think it was this series of mini.

[mnementh]

And given the vintage, all discrete, so no chance of figuring it out with a datasheet. Like how I scoured Google 3 times before actually finding some tech ref on that toroidal power transformer from my butt-ugly homebrew monoblock amp.

Well, if they hang around too much longer it'll be a moot point; all the caps will be dried up like the ones in my old Heath/Zenith Z-120. 

mnem

[vk6zgo]

A company I prevously worked for made equipment that was sold all over the world. Most had IEC power inlets. We used a Seward Supernova or two for production testing. However for some reason the senior manaement decided we could not do our own PAT  So they emplyed a contractor. He came in over the weekend. Amonst otherthings the passed a diecast box withe a IEC inelt but nothing else, not even earth connection, that was on my bench.  They had been told not to go into the R&D section. They alss took all the safety (T earth pin) plugs off the high power lasers. these were only supposed to be plugged ito the door interlocked outlets.
In production they took all the new and bagged IEC leads in stores and tested them. For the EU North American and Austrailian leads they cut the plugs off and fitted 13A ones 
His tester was a battery powered one with no high current earth or flash capability. He didn't get paid........

 

EDIT: It does beg the question though, why the hell wasn't he chaperoned?

Well they would not pay overtime for a competent employee to do the testing so why would they pay for one to watch a contractor? 

It also just highlights the difference between the average contractor and an engineer, especially if said contractor used to be a house basher, then he'd never ever come across such plugs and sockets, equally never come across clean earth varieties either.

Or an old style competent Technician.
These days it's all "monkey see, monkey do"----he probably did a one week course!

"Just last week I cudn't spell teknishun, now I are one!"

[VK5RC]

And given the vintage, all discrete, so no chance of figuring it out with a datasheet. Like how I scoured Google 3 times before actually finding some tech ref on that toroidal power transformer from my butt-ugly homebrew monoblock amp.

Well, if they hang around too much longer it'll be a moot point; all the caps will be dried up like the ones in my old Heath/Zenith Z-120. 

mnem

I would express it a different way
' if they hang around too long I will be dried up like those old Zenith /Heath caps'
😂, definitely past my prime here🤣

[vk6zgo]

Well, I bought a new scope. 1Ghz TDS784C for 66,483 yen.
 I think I'm at, what... 11 scopes now I think? I should sell some....

And for dessert, I bought a 334A Distortion Analyzer for 12,800 yen too. 
(Photos from the listings).

One step further down the calibration rabbit hole, now I'll fix this stuff up, to fix up the stuff I need to use to fix up the stuff I actually want to use... Possibly with a few more steps of fixing stuff in between..
Soon I'll have all the gear ready to re-calibrate the Tek 2467 scope I accidentally wiped the cal memory on when replacing the backup battery.... 

Such is the great circle of life TEA. 

Unless I'm badly mistaken about current exchange rates, that's a pretty damn good price. Congratulations!

Yeah, not a bad price for the 334A, considering what they were selling for here last year, I wrongly thought prices had dropped back to normal, as one made just over £50 this week, looking more closely it was a bit of a mess, with glued together panel meter and crusty flaking dial. 


David

Ahh yes, I remember it well.....

We had quite a few of these in my old work years back.

As a lab instrument, they are really good, but frankly, in some  Broadcast testing situations where you are doing distortion tests on a lot of sources under time constraints, they are a "pain in the bum!"

At one multi-transmitter site, they replaced much older manual instruments where, if we did an initial "null" on the first of multiple programme lines & Mod monitor outputs, we could just consecutively test across all of them, without having to touch the distortion controls.

Along came the 334a, & we were told "It's just 'the duck's guts', you don't have to manually null it!"

Unfortunately, it treated every test as if it was "the first one ever", & would painfully & slowly do its thing, burning up time.
Even if you did  manually null the thing, it still needed "auto" to get a really deep one -------still painfully slow.

After some years, they were replaced in that installation by AWA  "N & D sets".
These were also auto but had a very fast null, unlike the hp.

This soured me on the 334a, but they were OK in other installations where a single or maybe two sources needed testing.

[beanflying]

Playing with Crayons - first go with the nearest bit of junk to hand. Process is shave a little of the dried crust off the Crayon then rub it into the surface then a gentle wipe off after a few minutes. For existing engraving clear out the grooves and letters first.

More serious playing when I get some time and a useful how to below meanwhile. Just the thing for a crusty HP Dial 

[Andrew_Debbie]

Safety

BeO is carcinogenic in powdered form[12] and may cause a chronic allergic-type lung disease berylliosis. Once fired into solid form, it is safe to handle if not subjected to machining that generates dust, clean breakage releases little dust but crushing or grinding actions can pose a risk.[13] Beryllium oxide ceramic is not a hazardous waste under federal law in the USA.[citation needed]

Hmmm... is this a thing where the combination of the washer and thermal cement may or may not be better than modern silicone thermal pads?

Just curious. Yes, I get that this requires handling it either way.

mnem
*toddles off to be... slightly off*

Good question.   BeO has better thermal conductivity than just about any other electrical insulator.    Would a modern Si pad be good enough?  No idea.

The BeO washer is still attached to Q3, a 2N3104.     I don't want to attempt to remove it as that could be unsafe.   

I could replace Q3.  I'd have to adjust the input bias, which I could do if I had the recommended TE.   eBay is fresh out of HP 419A and the only Fluke 845AR is waay outside my budget    With time I'm sure I could find a more affordable accurate µVolt null meter.   Next project maybe?

The top of Q5 is frightening.  It looks like there is a thin layer of washer on the top of the can.
Q5 has a Dana part number.  Don't want to damage it.   Probably factory selected but that isn't much help.    I'm only giving myself one shot at this.   Will be researching thermal adhesives for Beryllium Oxide. 

[mansaxel]

It was the rental, plus the salaried on-site lab coats, plus the salaried data preparers, plus the salaried x, y, and Z personnel which were a mandatory part of the contract and got paid whether your machine was up or down that I'm talking aboot.

<snip>

You're offering a good background as to why it was so, and why the new compute bureaux are more successful.  The margin cost of doing another customer, or rather the cost setting that customer up to be able to buy services is essentially zero, and this has rejuvenated the model.

But: Try getting significant storage with low access times, GPU, or persistence. It very quickly goes into "fucking expensive" again.

[mansaxel]

Can't remember who said they missed out on one of these counters last week, item is in Germany;
https://www.ebay.de/itm/144248467377


Seller also has a 13C  oscilloscope;
https://www.ebay.de/itm/144248463110


David

It was me. They won't ship outside Germany. But I did ask about the Metcal, which also won't ship outside the isolated island.

[tautech]

Safety

BeO is carcinogenic in powdered form[12] and may cause a chronic allergic-type lung disease berylliosis. Once fired into solid form, it is safe to handle if not subjected to machining that generates dust, clean breakage releases little dust but crushing or grinding actions can pose a risk.[13] Beryllium oxide ceramic is not a hazardous waste under federal law in the USA.[citation needed]

Hmmm... is this a thing where the combination of the washer and thermal cement may or may not be better than modern silicone thermal pads?

Just curious. Yes, I get that this requires handling it either way.

mnem
*toddles off to be... slightly off*

Good question.   BeO has better thermal conductivity than just about any other electrical insulator.    Would a modern Si pad be good enough?  No idea.

The BeO washer is still attached to Q3, a 2N3104.     I don't want to attempt to remove it as that could be unsafe.   

I could replace Q3.  I'd have to adjust the input bias, which I could do if I had the recommended TE.   eBay is fresh out of HP 419A and the only Fluke 845AR is waay outside my budget    With time I'm sure I could find a more affordable accurate µVolt null meter.   Next project maybe?

The top of Q5 is frightening.  It looks like there is a thin layer of washer on the top of the can.
Q5 has a Dana part number.  Don't want to damage it.   Probably factory selected but that isn't much help.    I'm only giving myself one shot at this.   Will be researching thermal adhesives for Beryllium Oxide. 

Interesting predicament. 
Dana did themselves no favors wiring Q5 like that when if they had spread the leads equidistant around the Q5 can it would've probably never moved at all however it's not like it's for Q5 cooling only Q3/Q5 thermal bonding and certainly BO will offer the fastest thermal balancing but is that speed really necessary in this application ?

I'd be very tempted to desolder Q5 so to remove any surplus lead length and just superglue the buggers together (BO washer between) and resolder Q5 leads and call it done !

[Robert763]

Just did some research and realised the OKI/Metcal the Dwagon guilted me in to buying may have a tip availablity problem.
The original PHT tips seem to be discontinued. They used a CA-1 coil. The later SFV tips fit a CA-2 or CA-3 coil. The CA2 will fit the original handle but is also discontinued. So depending on what coil it has I may have to either scrounge around for tips or fork out £80 for a PS-HC3 handle and coil 
Will have to wait and see what arrives.

Awww... fudge. If I'd realized, I wouldn't have posted so desperately. Haven't been shopping new Oki/Metcal for a while. Hopefully you can score an appropriate handle at a sane price used.

Tho, for the price, if that comes with the sleeper stand, still good just for that. My experiment with a homebrew sleeper stand indicates at least the MX-500 is pretty forgiving re: sensing the magnet.

mnem
 

Only the standard stand.
There are NOS PTH bits around. I'm not buying anything until I find out what coil is fitted. I Assume the CA-2 was introduced to allow use of the later SxV tips. I've not been able to find definitive info on this or the differences between CA-1, 2 & 3 coils.  Again I'm not spending any time on it until I know what I've got.

[Robert763]

A company I prevously worked for made equipment that was sold all over the world. Most had IEC power inlets. We used a Seward Supernova or two for production testing. However for some reason the senior manaement decided we could not do our own PAT  So they emplyed a contractor. He came in over the weekend. Amonst otherthings the passed a diecast box withe a IEC inelt but nothing else, not even earth connection, that was on my bench.  They had been told not to go into the R&D section. They alss took all the safety (T earth pin) plugs off the high power lasers. these were only supposed to be plugged ito the door interlocked outlets.
In production they took all the new and bagged IEC leads in stores and tested them. For the EU North American and Austrailian leads they cut the plugs off and fitted 13A ones 
His tester was a battery powered one with no high current earth or flash capability. He didn't get paid........

 

EDIT: It does beg the question though, why the hell wasn't he chaperoned?

Well they would not pay overtime for a competent employee to do the testing so why would they pay for one to watch a contractor? 

It also just highlights the difference between the average contractor and an engineer, especially if said contractor used to be a house basher, then he'd never ever come across such plugs and sockets, equally never come across clean earth varieties either.

Or an old style competent Technician.
These days it's all "monkey see, monkey do"----he probably did a one week course!

"Just last week I cudn't spell teknishun, now I are one!"

A week?  PAT is 1/2 day. at most.
In the UK they brought in a requirment for sparkies working on higher risk  domestic installations to be "Part P" registered. I checked on one of the smaller registraion bodies requirement. It was a 3 day course. There were no entry requirements but "if you have done no electrical work before we suggest you take our 5 day bsic course". You do of couse have to pay there annual registration fee to keep the "qualification". Two weeks from zero to qualified to do any domestic electrical insallation 

[Saskia]

swell. do they come with liability coverage in case they burn your house down ?

[AVGresponding]

A week?  PAT is 1/2 day. at most.
In the UK they brought in a requirment for sparkies working on higher risk  domestic installations to be "Part P" registered. I checked on one of the smaller registraion bodies requirement. It was a 3 day course. There were no entry requirements but "if you have done no electrical work before we suggest you take our 5 day bsic course". You do of couse have to pay there annual registration fee to keep the "qualification". Two weeks from zero to qualified to do any domestic electrical insallation 

The management level PAT course (the one I did) is a 2-day one, with an open book "exam" at the end of it. It's a multiple choice paper, 40 or 50 questions iirc, and took me about 10 of the allotted 45 minutes, and that's with checking all my answers at least 3 times. I was annoyed that I got one wrong. It grants you an NVQ level 3 at the end of it. I think that's the fastest "qualification" I've ever done...

The NAPIT part P thing is even worse than you think; it allows you to inspect and sign off other people's work, and from what I've seen it is more often the likes of kitchen fitters than electricians that do it.
Part P doesn't fly here; you need C&G 2391 to get your testing money.

[mansaxel]

A week?  PAT is 1/2 day. at most.
In the UK they brought in a requirment for sparkies working on higher risk  domestic installations to be "Part P" registered. I checked on one of the smaller registraion bodies requirement. It was a 3 day course. There were no entry requirements but "if you have done no electrical work before we suggest you take our 5 day bsic course". You do of couse have to pay there annual registration fee to keep the "qualification". Two weeks from zero to qualified to do any domestic electrical insallation 

The management level PAT course (the one I did) is a 2-day one, with an open book "exam" at the end of it. It's a multiple choice paper, 40 or 50 questions iirc, and took me about 10 of the allotted 45 minutes, and that's with checking all my answers at least 3 times. I was annoyed that I got one wrong. It grants you an NVQ level 3 at the end of it. I think that's the fastest "qualification" I've ever done...

The NAPIT part P thing is even worse than you think; it allows you to inspect and sign off other people's work, and from what I've seen it is more often the likes of kitchen fitters than electricians that do it.
Part P doesn't fly here; you need C&G 2391 to get your testing money.

Here, there are slightly more serious requirements: https://www.elsakerhetsverket.se/globalassets/foreskrifter/engelska/elsak-2017-4-english.pdf

Signing off on other peoples installations requires A or AL, that is training plus 4 years documented experience.

[AVGresponding]

The first thing many of us do when we go into the wholesalers (after grabbing a free mocchaccino from the machine) is to pick up the latest copy of Professional Electrician and turn to the Caught On Camera pages.  https://professional-electrician.com/tag/caught-on-camera/

One of these days I'll send in some from my Hall of Shame, as I call my collection of horror pictures.

[beanflying]

No TEA.

[factory]

Safety

BeO is carcinogenic in powdered form[12] and may cause a chronic allergic-type lung disease berylliosis. Once fired into solid form, it is safe to handle if not subjected to machining that generates dust, clean breakage releases little dust but crushing or grinding actions can pose a risk.[13] Beryllium oxide ceramic is not a hazardous waste under federal law in the USA.[citation needed]

Hmmm... is this a thing where the combination of the washer and thermal cement may or may not be better than modern silicone thermal pads?

Just curious. Yes, I get that this requires handling it either way.

mnem
*toddles off to be... slightly off*

Good question.   BeO has better thermal conductivity than just about any other electrical insulator.    Would a modern Si pad be good enough?  No idea.

The BeO washer is still attached to Q3, a 2N3104.     I don't want to attempt to remove it as that could be unsafe.   

I could replace Q3.  I'd have to adjust the input bias, which I could do if I had the recommended TE.   eBay is fresh out of HP 419A and the only Fluke 845AR is waay outside my budget    With time I'm sure I could find a more affordable accurate µVolt null meter.   Next project maybe?

The top of Q5 is frightening.  It looks like there is a thin layer of washer on the top of the can.
Q5 has a Dana part number.  Don't want to damage it.   Probably factory selected but that isn't much help.    I'm only giving myself one shot at this.   Will be researching thermal adhesives for Beryllium Oxide. 

I'm guessing you meant Q3 is a 2N1304 (Ge) and not the 2N3104 (Si), the diagram & parts list both mention 2N1304. 

Oh and a hp 419A would probably be out of budget too, since a certain Carlson did a video on them  , they used to sell for bugger all.

David

[factory]

Can't remember who said they missed out on one of these counters last week, item is in Germany;
https://www.ebay.de/itm/144248467377


Seller also has a 13C  oscilloscope;
https://www.ebay.de/itm/144248463110


David

It was me. They won't ship outside Germany.

Why did they put this in the description if they don't ship outside Germany? 

Versand ins Ausland nur mit Telefonangabe !!!
Bieten Sie nicht wenn Sie damit nicht einverstanden sind oder wählen eine versicherte Versandoption.

Translates to; Shipping abroad only with telephone information !!!
Do not bid if you do not agree or choose an insured shipping option.

David

[McBryce]

Probably because they copy/paste the entire paragraph into the description of every article they sell?

McBryce.

[Andrew_Debbie]

100GΩ input impedance on the 200V range!   

This thing must have been a small fortune when new!

Interesting, is this a typo ?

I doubt it's a typo. Easily achieved with a bootstrapped input amp.

Run of the mill spec for decent multimeters nowadays is ">10G input impedance" but they don't specify how much "greater than". In practice it's often in the T region but >10G is all they'll be prepared to guarantee because testing input leakage currents at that level is time consuming and therefore expensive. Measured input leakage current on my 34461A is on the close order of 3-4 pA at 0V (and knowing the architecture, which among other things has a bootstrapped input amp, will be pretty constant and not alter much with respect to input voltage). At 10V that would be  2.5 T .

The 5100 has a bootstrapped input.   20 and 200VDC go through a high impedance high voltage buffer first.   The HV buffer has 300V supply rails.   



AC selects the averaging converter.  My 5100 doesn't have option 10.


AC has a FET input after the attenuator network.   The dual FET has a Dana part number, which suggests hand selection.   The RMS board is similar but uses an LF356 instead of the dual FET+AD518.    The input clamp uses diode connected UHF transistors.    Another example of  Dana never choosing the cheap option.