Test Equipment Anonymous (TEA) group therapy thread

[nixiefreqq]

welcome to 4937.

[Saskia]

as for nutria, they damage our dams which protect us against the raging see and the storm surges.
we can't have that, so we sacrifice them to John Moses Browning

[bd139]

welcome to 4937.

Was ok until you disgraced it with that TI 

[nixiefreqq]

welcome to 4937.

Was ok until you disgraced it with that TI 

“Everything has beauty, but not everyone sees it.” —Confucius

[mansaxel]

5440 update:

I've gotten a trace! Again. But, still, only if I select Single Sweep. Auto Trigger won't cut it.

I can observe the waveform from the vertical plugin at the input of the trig source selector switch. The terminations are OK, and the selector switch does its thing. I've spent some more time with contact cleaner on all the switches. I'm bent to thinking that the rest of the signal chain is sort-of-working, since I can use the signal from the vert plugin to trig. Albeit through standing on my head and singing the Marseillaise (eh, I mean "single sweep") . Bedtime or thereabouts now, will ponder on through the week.

[bd139]

welcome to 4937.

Was ok until you disgraced it with that TI 

“Everything has beauty, but not everyone sees it.” —Confucius

Clearly you have beer goggles on 

[nixiefreqq]

welcome to 4937.

Was ok until you disgraced it with that TI 

“Everything has beauty, but not everyone sees it.” —Confucius

Clearly you have beer goggles on 

we probably don't want to go down this path.   you know what happens if med gets into it.  (stripper alert!!!!)

[tggzzz]

as for nutria, they damage our dams which protect us against the raging see and the storm surges.
we can't have that, so we sacrifice them to John Moses Browning

"Nutria" makes me think of a food supplement for the elderly or feebleminded[1].  Shades of soylent green.

Something like


[1] e.g.those that eat blue-green algae pond scum, because it is promoted as natural.

[Specmaster]

welcome to 4937.

Was ok until you disgraced it with that TI 

Well, you can't even call that a calculator regardless of what make or type it is unless at least 45 buttons 

[med6753]

welcome to 4937.

Was ok until you disgraced it with that TI 

“Everything has beauty, but not everyone sees it.” —Confucius

Clearly you have beer goggles on 

we probably don't want to go down this path.   you know what happens if med gets into it.  (stripper alert!!!!)

No worries. She retired and burned her g-string. 

[Vince]

DIODES


1H20 AM, I am finally done  organizing my diodes, after spending countless hours identifying them and downloading datasheets.

Deciding how to organize them is even more difficult, because you need to make choices.... identifying them is a chore and takes forever, but it's somehow relaxing, there are no choices to be made, no stress... you just go through them one by one and that's all.

Anyway, tried to compromise as always between putting them all in one big bag... no, or using up an entire drawer unit, nope either.

So at the end the compromise was two plastic boxes and only 4 drawers.

The small axial stuff bagged, in the plastic containers, with a few cardboard dividers to help of course :

Box #1
- Small Signal
- Germanium
- Zener < 10V
- Zener >= 10V


Box #2
- Rectification <= 1A
- Rectification > 1A
- Fast Avalanche
- Schottky

Drawers, sorted by prefix

#1 : 1 , 1N 
#2 : BY , F 
#3 : G , D , S
#4 : NO ID, couldn't find neither a datasheet nor even basic specs in a short form catalog.

Spreadsheet below.


Retrospectively, I kinda enjoyed searching all that... reading all these datasheet, old and modern, about all kinds of diodes of all kinds of ratings...

- You get a feel for what parameters are typical for each type, ballpark.

- You get to learn about old manufacturers long defunct, or still alive but that you never had heard before.

- You get to see all the BS in the datasheets, and how marketing sometimes appears to be writing the datasheet rather than the technical people. Most notably the overwhelming use of the buzz word " ULTRA FAST " diodes. Used and abused, so much so that it doesn't mean anything anymore and I stopped taking any notice of it. It's just a marketing buzzword nothing more... It looks like the marketing dept were all very afraid that if you didn't put "ULTRA FAST "on the cover page, nobody would buy your diodes....  It's so bad that even a big name like Vishay, no less, in one datasheet, stated in huge bold characters ULTRA FAST at the top of the datasheet and..... nowhere in the datasheet does it tell you how fast it is  !!    Engineers don't need to know... buying dept bought some "ULTRA FAST" diodes, surely they should be alright  ! 

- You get to learn what kind of part number is out there, and how they are "formed", how different manufacturers code parameters into their part numbers, there is variety out there.

BUT !!!!    But.... by far the most useful thing I got out of all this, spending so many hours researching diodes... is that I will never.. never... never misspell freaking SCHOTTKY ever again !!!!    Oh boy, was worth it just for that !

[Specmaster]

Just a reminder to you all that even though some Governments are not even discussing Covid (certainly true for the UK  ) it has not gone away is now making a comeback with a rise of over 45% of cases since the Queens Jubilee. I hope that you are still wearing face masks when in shops and other crowded places etc?

This weekend, it has presented itself in the middle of the family, my 2 Sister in Laws went to see Pretty Woman the musical at the Savoy Theatre in London last week and this weekend is suffering badly with Covid. SWMBO has been running around like a headless chicken, going shopping for her Sister and also her elderly mum etc. I know for a fact that SIL has not been wearing her mask because she says that it's gone away otherwise it would be all over the news etc. 

[tautech]

We didn't bother with masks for 3 full and 2 setting up days at EMEX.
Prob ~50% of visitors wore them but very few exhibitors did. 

[tautech]

DIODES

No 1N4148 in the high power listings ? 

They CAN handle 20A for a few us.

[mansaxel]

it has not gone away

It never will. We'll get better at dealing with it, both as organisms and organisations of people. But no, it's out there. And that's how it's going to be.

Observation: The same people around a 4-seater table in a danish train (Copenhagen-Hamburg) are not deemed a risk in Denmark, but as soon as Die Bahn takes over in Flensburg, it's Maskenpflicht all over. I knew, having read up and also been to Portugal (where it's mandatory on public transport) so had a box with masks ready. A couple other people (from Sweden) obviously hadn't read the news, and since masks are quite uncommon in Sweden -- only mandated in healthcare at the moment, and never were much mandated apart from there -- they'd sort of forgotten how things are handled in the rest of the world. I and some other people quickly supplied them and all was well. Herr Schaffner was happy. And, of course; there's a story to this, but at the interfaces between systems for managing the epidemic, it becomes sometimes right silly.

I know too little to judge in the matter.

The only thing I'm going to state is that vaccinations are a good thing. As many as possible should take them. There, we have close to 200 years of improving science.

[Vince]

DIODES

No 1N4148 in the high power listings ? 

They CAN handle 20A for a few us.

 


No. If you want to play that game, then I will point out that the "Beefy" ones can do 800Amps surge !! 

[tautech]

DIODES

No 1N4148 in the high power listings ? 

They CAN handle 20A for a few us.

 


No. If you want to play that game, then I will point out that the "Beefy" ones can do 800Amps surge !! 

Yep I also thought that funny when my EE lecturer mate told me that. 
He had some students do an exercise to find the limits of what a 1N4148 could do and that's what they proved however not known is which part of the world was where they were sourced from. 

[Vince]

According to the datasheet I have got, they are rated at 2A surge, for 1us.

So 20 amps is quite a stretch, good diodes they were indeed ! 

[GreyWoolfe]

I live in the hottest part of the UK and our local record is 38.1oC. Hit 34oC yesterday and that wasn’t even really bothering me.

But 41, fuck that 

Yea it's bad. Makes me wonder how pioneers could take it without ice water or AC. But then they couldn't wish for better because it didn't exist so its just reality. I don't think we'd survive very long if went went back in time being spoiled as we are. 

Yeah I always consider the moment that America goes down the shitter will be when there is no AC for some reason or another. It'll start with the Karens and finish with the Cleetuses 

It'll probably be initiated by someone firing up their Tek tube scope collection all at one time 

I've heard it said, only slightly tongue in cheek, that A/C made the South USA inhabitable.

But the USA is a land of surprises. Until the early 20th century there was a thriving trade exporting ice from New England to the Caribbean and even as far as India. https://en.wikipedia.org/wiki/Ice_trade

In Tejas, AC is no luxury; it's survival gear for sure... There's a reason it's called the "Energy Corridor", and not just the oil that used to be there. 

mnem
 

All week here in Flori-DUH, temps have been in the 90's F with a heat index well into the 100's.  Mrs GreyWoolfe read something on FB saying it's the sun rubbing its balls across the state.  Thank God for AC.  We had our 7.9 KW solar panel system installed last weekend, waiting for the energy company to come and install a 2 way meter.  After that, city inspection and then the system gets turned on.  Looking at the desktop panel, it is 8:17 pm and still 83 F.

[Vince]

I guess that's the positive side of things... the very hot states in the US are also those with lots of sun, so you can use solar energy to power the A/C, so it balances out, you consumer the energy that you produce...

Today (yesterday ? Am losing it...) heard on the news here that in some US state literally thousands of cows died because of the sun, all in one day...   

Farmers said it's usual for a HANDFUL to die because of too much heat, but thousands, even they were astonished....

[mnementh]

...Thanks everyone for the info on how these things work. I can now button it back up and move on to the next item in the list...

Not quite... I know you may already know this, but just in case you don't; these things are designed to use a deep-cycle battery, which has a bit higher IR than your car/motorcycle starting battery there, and the float charge it puts across the battery terminals can cook a starting battery to death.

Once you're back among the gainfully employed, you'll want to invest in a SLA/GMA battery of similar capacity to the one you took out of the thing. Or maybe one small enuf to fit inside. 

Cheers!

mnem

In point of fact a liquid lead acid such as a car battery handles the float voltage of an average UPS just fine; it's lower than the float voltage of a car charger system (usually around 13.8V as opposed to 14.4V for a normal 6-cell battery). The main problem with using a liquid lead acid is you'll get increased corrosion since these things are designed to use SLA batteries which don't really spit much acid out unless you heavily abuse them.
If you want to extend the life of an SLA if you get one for it, make sure your float is 13.2-13.6V, unless you keep the battery in the fridge... in which case 13.8V is fine. Try not to get a cheap Chinesium SLA, they aren't that much cheaper than a decent brand like Yuasa or Hawker Siddeley, or Haze, but they use badly recycled lead and tend to have very much shorter lifespans, very much less capacity, and very much higher ESR.

Try hooking a small-med starting battery to a UPS. You'll hear it boiling in a week or two. Car starting... maybe okay due to the mass. But you'll damage the starting battery if you let it run deep-discharge more than a few times.

As for Chinesium batteries... I've been buying ExpertPower and PowerSonic for myself for decades, and seen both brands used by major players for refits on UPSes from 1500VA to 5000VA. They cost ~1/2 of that Yuasa (if genuine)... and Yuasa (Taiwan) gets their lead from recycling plants in China, same as the rest of the world.

Cheers,

mnem
 

[mnementh]

as for nutria, they damage our dams which protect us against the raging see and the storm surges.
we can't have that, so we sacrifice them to John Moses Browning

"Nutria" makes me think of a food supplement for the elderly or feebleminded[1].  Shades of soylent green.

Something like   

[1] e.g.those that eat blue-green algae pond scum, because it is promoted as natural.

*adds another item to the shopping list*

mnem
Hey, I'm low on Soylent Green.

[med6753]

An auction score from the FB group Old Tek Scopes. He didn't state how much in total he paid but he did state that the plug-in's were as little as $8/each. Given the total it still adds up to a significant chunk of change but the total amount of gear is unreal.   

And I thought two Type 547's, five plug-in's and two carts for $200 was a score.   

[mnementh]

Well, fuck-a-doodle. Looks like another SK sale, ehhh?

mnem
 

[mnementh]

DIODES

No 1N4148 in the high power listings ? 

They CAN handle 20A for a few us.

 


No. If you want to play that game, then I will point out that the "Beefy" ones can do 800Amps surge !! 

Yep I also thought that funny when my EE lecturer mate told me that. 
He had some students do an exercise to find the limits of what a 1N4148 could do and that's what they proved however not known is which part of the world was where they were sourced from. 

Well, there's gonna be quite a difference between "rated survivable surge current" and "What can we measure while blowing it into a puff of smoke...?" surge current... 

mnem