Test Equipment Anonymous (TEA) group therapy thread

[Cerebus]

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... 

On a slightly more prosaic note stress ratings for passives are usually specified in terms of parameter shifts e.g. (made up example) Resistance value will shift no more than 0.1% for 10x rated current for 1 sec, < 0.2% for 100x rated current for 0.2s. One could extend this to the rather more nebulous parameters of diodes.

So it's more of a case of "How much you can overload it depends on how much you're prepared to damage it, and what you're going to count as damage". Obviously, vapourisation counts as "unacceptable damage". Unless it's a RIFA, in which case it counts as justifiable homicide.

[mnementh]

Oh... and while it's still here... for a few more minutes, anyways...

HAPPY FATHER'S DAY, ALL YOU FREAKS!

And if you aren't one... oh, just enjoy it vicariously with those who had a good one. 

Mine was excellent; I got my dad the perfect wallet, and after pulling my hair out trying to find a way to make baseball games happen for him without effing cable TV, Amazon saved the day with MLBTV through their Prime Video app. And half-price on the full season for Father's Day!



And for those who're wondering about this...

"I'm thinking... if I use it, I can put the whole pot in there. I won't have to go back for refills..." ~Dad

mnem
                                                   

[mnementh]

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... 

On a slightly more prosaic note stress ratings for passives are usually specified in terms of parameter shifts e.g. (made up example) Resistance value will shift no more than 0.1% for 10x rated current for 1 sec, < 0.2% for 100x rated current for 0.2s. One could extend this to the rather more nebulous parameters of diodes.

So it's more of a case of "How much you can overload it depends on how much you're prepared to damage it, and what you're going to count as damage". Obviously, vapourisation counts as "unacceptable damage". Unless it's a RIFA, in which case it counts as justifiable homicide.

Remember kids... the difference between "Science" and "blowing stuff up for shits and giggles" is DOCUMENTATION.

mnem
So learn to take copious notes early and consistently...

[Cubdriver]

I've done a bit of poking and prodding at that NLS DVM I mentioned a few days ago.  After replacing a thyratron tube that was cracked and had vented to atmosphere, I've gotten the stepper relays to run fairly reliably and it seems to measure more or less properly.


One big issue is that the relay contacts are cruddy as it sat unused for an unknown length of time in a basement, so unlike the full display in the picture above, in many instances one or more of the digits doesn't light up.


I'm working on making up a longer video showing the troubleshooting (actually sprung for editing software to try to string clips together for a change), but in the meantime, here is a quickie video showing how to clean the stepper relay contacts using Deoxit and a piece of paper.  They're still not perfect (some skips still), but are a whole lot better than they were a few nights ago.


Now to do the rest of them...

-Pat

[AVGresponding]

...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
 

If a UPS is boiling a car battery, it would cook an SLA in half the time; the float voltage should be lower, and if it isn't, it's either (1) badly adjusted and/or (2) a POS.

If you deep discharge any lead acid you reduce its life, including so called deep cycle ones, and you do not deep cycle UPS batteries, unless you (a) have a lot of power cuts and also (b) don't do a controlled power down when the mains fails, and just run the UPS until low battery cutoff.

Maybe you have routinely seen One Hung Low brands in tiny UPSs like that, but I can assure you that the kind of places that use proper machines (50kVA and up) would shit a brick if you put crap like that in their battery string.

Yuasa and the like have much better quality lead. I don't care if it does come from the same place, they use the premium line, and the locals use the value brand.

[TERRA Operative]

I've done a bit of poking and prodding at that NLS DVM I mentioned a few days ago.  After replacing a thyratron tube that was cracked and had vented to atmosphere, I've gotten the stepper relays to run fairly reliably and it seems to measure more or less properly.


One big issue is that the relay contacts are cruddy as it sat unused for an unknown length of time in a basement, so unlike the full display in the picture above, in many instances one or more of the digits doesn't light up.


I'm working on making up a longer video showing the troubleshooting (actually sprung for editing software to try to string clips together for a change), but in the meantime, here is a quickie video showing how to clean the stepper relay contacts using Deoxit and a piece of paper.  They're still not perfect (some skips still), but are a whole lot better than they were a few nights ago.
youtube.com/watch?v=eeJXLf0qoNM

Now to do the rest of them...

-Pat

Ooohhhhhh, now that is some real quality porn right there.....

Do want! Tinkering with that at night with some random electronics youtube vids humming in the background is the dream.


Let that deoxit soak for a bit, the contacts will come good eventually with some excersise.

[med6753]

I've done a bit of poking and prodding at that NLS DVM I mentioned a few days ago.  After replacing a thyratron tube that was cracked and had vented to atmosphere, I've gotten the stepper relays to run fairly reliably and it seems to measure more or less properly.


One big issue is that the relay contacts are cruddy as it sat unused for an unknown length of time in a basement, so unlike the full display in the picture above, in many instances one or more of the digits doesn't light up.


I'm working on making up a longer video showing the troubleshooting (actually sprung for editing software to try to string clips together for a change), but in the meantime, here is a quickie video showing how to clean the stepper relay contacts using Deoxit and a piece of paper.  They're still not perfect (some skips still), but are a whole lot better than they were a few nights ago.
youtube.com/watch?v=eeJXLf0qoNM

Now to do the rest of them...

-Pat

Ooohhhhhh, now that is some real quality porn right there.....

Do want! Tinkering with that at night with some random electronics youtube vids humming in the background is the dream.


Let that deoxit soak for a bit, the contacts will come good eventually with some excersise.

I want to hear the steppers clicking as the voltage varies. 

[ch_scr]

I've done a bit of poking and prodding at that NLS DVM I mentioned a few days ago.  After replacing a thyratron tube that was cracked and had vented to atmosphere, I've gotten the stepper relays to run fairly reliably and it seems to measure more or less properly.


One big issue is that the relay contacts are cruddy as it sat unused for an unknown length of time in a basement, so unlike the full display in the picture above, in many instances one or more of the digits doesn't light up.


I'm working on making up a longer video showing the troubleshooting (actually sprung for editing software to try to string clips together for a change), but in the meantime, here is a quickie video showing how to clean the stepper relay contacts using Deoxit and a piece of paper.  They're still not perfect (some skips still), but are a whole lot better than they were a few nights ago.
youtube.com/watch?v=eeJXLf0qoNM

Now to do the rest of them...

-Pat

Ooohhhhhh, now that is some real quality porn right there.....

Do want! Tinkering with that at night with some random electronics youtube vids humming in the background is the dream.


Let that deoxit soak for a bit, the contacts will come good eventually with some excersise.

I want to hear the steppers clicking as the voltage varies. 

It also really drives home the point: these numbers shown are only a finite approximation of reality...

[Saskia]

used to ventilate ground hogs on a regular basis. 

the farmer who owned the hay field behind the house asked me to.

sometimes his hay wagon would fall axle deep into those damn rodent holes.

never ate one though.   around here they often have hepatitis.

edit - popped one once on the second of feb.  felt bad about the timing but the poor thing was foaming at the mouth and spinning in circles in the middle of an icy dirt road.  probably rabies.   did not eat that one either.

Hope you did not touch it, did not get any body fluids onto anything and did dispose of the body properly to eliminate contamination and infection of other animals or humans.
I'd suggest a flame thrower or napalm ...

[Specmaster]

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.

It's interesting when you compare national figures against each other, take the information gleaned from this source https://www.cnbc.com/2022/04/28/denmark-the-first-country-to-halt-its-covid-vaccination-program.html and you can see that the number of recorded cases per million people can show how some countries have handled the virus reaction and suppression better than others.

For instance, on Feb 13th 2022, looking at Denmark, Sweden, UK and New Zealand for example, we can see the following results, form your own opinions.
Denmark 7,970
Sweden   1,540
UK          1,060
New Zealand   99.

[capt bullshot]

I've done a bit of poking and prodding at that NLS DVM I mentioned a few days ago.  After replacing a thyratron tube that was cracked and had vented to atmosphere, I've gotten the stepper relays to run fairly reliably and it seems to measure more or less properly.


One big issue is that the relay contacts are cruddy as it sat unused for an unknown length of time in a basement, so unlike the full display in the picture above, in many instances one or more of the digits doesn't light up.


I'm working on making up a longer video showing the troubleshooting (actually sprung for editing software to try to string clips together for a change), but in the meantime, here is a quickie video showing how to clean the stepper relay contacts using Deoxit and a piece of paper.  They're still not perfect (some skips still), but are a whole lot better than they were a few nights ago.
youtube.com/watch?v=eeJXLf0qoNM

Now to do the rest of them...

-Pat

Ooohhhhhh, now that is some real quality porn right there.....

Do want! Tinkering with that at night with some random electronics youtube vids humming in the background is the dream.


Let that deoxit soak for a bit, the contacts will come good eventually with some excersise.

I want to hear the steppers clicking as the voltage varies. 

That's why we Germans would call this a "Klapperatismus"

[nixiefreqq]

used to ventilate ground hogs on a regular basis. 

the farmer who owned the hay field behind the house asked me to.

sometimes his hay wagon would fall axle deep into those damn rodent holes.

never ate one though.   around here they often have hepatitis.

edit - popped one once on the second of feb.  felt bad about the timing but the poor thing was foaming at the mouth and spinning in circles in the middle of an icy dirt road.  probably rabies.   did not eat that one either.

Hope you did not touch it, did not get any body fluids onto anything and did dispose of the body properly to eliminate contamination and infection of other animals or humans.
I'd suggest a flame thrower or napalm ...

called the state game warden assigned to our area and he said to take a shovel with a long handle or a stout stick and move it off the road. (it was a dirt road that cut between two corn fields and had no thru traffic.  only the farmer used it to get from his barn to the hay fields behind my former house.  kids did use it for night time entertainment judging from the number of used condoms and beer bottles laying around)

the temperature was just below freezing that day and much colder at night.  the game warden advised not to go near it again for at least 4-6 hours when it would be cold to the core and that the virus became de-activated when cold.  no idea if he was right about that but i checked a couple of times during the day and at least once after dark and nothing had disturbed it.  the game warden said there was no need for him to come remove it.  also advised the farmer of its location and he said to just leave it be.

but that was back in about 1986 or so.   today a biohazard team in space suits would probably be airlifted into the cornfield.

[TERRA Operative]

I've done a bit of poking and prodding at that NLS DVM I mentioned a few days ago.  After replacing a thyratron tube that was cracked and had vented to atmosphere, I've gotten the stepper relays to run fairly reliably and it seems to measure more or less properly.


One big issue is that the relay contacts are cruddy as it sat unused for an unknown length of time in a basement, so unlike the full display in the picture above, in many instances one or more of the digits doesn't light up.


I'm working on making up a longer video showing the troubleshooting (actually sprung for editing software to try to string clips together for a change), but in the meantime, here is a quickie video showing how to clean the stepper relay contacts using Deoxit and a piece of paper.  They're still not perfect (some skips still), but are a whole lot better than they were a few nights ago.
youtube.com/watch?v=eeJXLf0qoNM

Now to do the rest of them...

-Pat

Ooohhhhhh, now that is some real quality porn right there.....

Do want! Tinkering with that at night with some random electronics youtube vids humming in the background is the dream.


Let that deoxit soak for a bit, the contacts will come good eventually with some excersise.

I want to hear the steppers clicking as the voltage varies. 

That's why we Germans would call this a "Klapperatismus"

It reminds me of an old telephone exchange, wonder if it sounds similar....

[Saskia]

heat (as in fire) would destroy the virus as well. Naturally this may be problematic if it's been dry for a prolonged time and the wild fire index is at a critical point ...

[Saskia]

I've done a bit of poking and prodding at that NLS DVM I mentioned a few days ago.  After replacing a thyratron tube that was cracked and had vented to atmosphere, I've gotten the stepper relays to run fairly reliably and it seems to measure more or less properly.


One big issue is that the relay contacts are cruddy as it sat unused for an unknown length of time in a basement, so unlike the full display in the picture above, in many instances one or more of the digits doesn't light up.


I'm working on making up a longer video showing the troubleshooting (actually sprung for editing software to try to string clips together for a change), but in the meantime, here is a quickie video showing how to clean the stepper relay contacts using Deoxit and a piece of paper.  They're still not perfect (some skips still), but are a whole lot better than they were a few nights ago.
youtube.com/watch?v=eeJXLf0qoNM

Now to do the rest of them...

-Pat

Ooohhhhhh, now that is some real quality porn right there.....

Do want! Tinkering with that at night with some random electronics youtube vids humming in the background is the dream.


Let that deoxit soak for a bit, the contacts will come good eventually with some excersise.

I want to hear the steppers clicking as the voltage varies. 

That's why we Germans would call this a "Klapperatismus"

It reminds me of an old telephone exchange, wonder if it sounds similar....

Wintergatan and the marble machine come to mind.

[Specmaster]

Has anyone ever seen a calculator like this at all? I can't recall seeing anything like myself.

https://www.ebay.co.uk/itm/313959676347

[tggzzz]

I've done a bit of poking and prodding at that NLS DVM I mentioned a few days ago.  After replacing a thyratron tube that was cracked and had vented to atmosphere, I've gotten the stepper relays to run fairly reliably and it seems to measure more or less properly.


One big issue is that the relay contacts are cruddy as it sat unused for an unknown length of time in a basement, so unlike the full display in the picture above, in many instances one or more of the digits doesn't light up.


I'm working on making up a longer video showing the troubleshooting (actually sprung for editing software to try to string clips together for a change), but in the meantime, here is a quickie video showing how to clean the stepper relay contacts using Deoxit and a piece of paper.  They're still not perfect (some skips still), but are a whole lot better than they were a few nights ago.
youtube.com/watch?v=eeJXLf0qoNM

Now to do the rest of them...

-Pat

Ooohhhhhh, now that is some real quality porn right there.....

Do want! Tinkering with that at night with some random electronics youtube vids humming in the background is the dream.


Let that deoxit soak for a bit, the contacts will come good eventually with some excersise.

I want to hear the steppers clicking as the voltage varies. 

That's why we Germans would call this a "Klapperatismus"

It reminds me of an old telephone exchange, wonder if it sounds similar....

There are a few noises that, for me, are very evocative of the past. The Merlin aeroengine is one, Strowager exchanges are another, and then there's ASR33 teletypes.

[nixiefreqq]

Has anyone ever seen a calculator like this at all? I can't recall seeing anything like myself.

https://www.ebay.co.uk/itm/313959676347

looks like the one the predator wore on his wrist.

[med6753]

Has anyone ever seen a calculator like this at all? I can't recall seeing anything like myself.

https://www.ebay.co.uk/itm/313959676347

looks like the one the predator wore on his wrist.

[Brumby]

J2E details are difficult to track-down, but fortunately they're almost identical to the previous generators in the series.

The only challenge is that it is of poor quality.  You can make out the components, but the values are next to unreadable.

See iff the attached will yeild-up better information!

Thank you for your efforts, but I already have those - and it is because of the similarity of design that I have been encouraged to attempt a redraw, being able to pick up values from the clearer image and use them in the less readable one.

I quickly noticed two differences between the circuits, the first being the metering circuit.  The second was filtering of the HT supply where the earlier versions had a 16uF and 32uF caps ... and the later had a 16uF and two 16uF caps (clearly BOM rationalisation).


Now tackling the learning curve for KiCad...  Not that I can't get anything happening - just that it's taking me far longer than I would like.  I know it's just a matter of becoming familiar - but I'm an impatient so-and-so at times.   

[Vince]

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.   

Look Allison, it pains me to tell you this, but all that stuff is old worthless junk, a recycler would even CHARGE you to waste his time and petrol to come collect all that stuff.
But because your husband was my best friend, I will empty the garage myself for free. No need to thank me, I am trying to ease your pain, I owe that to your husband.


Wow, impressive collection... this guy clearly had a fetish for the 1A4 4 channel plugin ! I counted 12 of them, 48 channels total... maybe the guy had a grandiose plan of putting together a vintage logic analyzer or something !

A sampling scope as well wow...

And not one but TWO type 180A time mark generator like mine ! Am jealous...

And look in the background to the left ! Another of this rare huge HP counter like the two Cubdriver just got !! 
Looks in nice shape as well. It's the old version pre-Nixie, can't recall how these early vertical form factor displays were called ?
Anyway the one Cubdriver got had 6 "digits" + two small meter movements to their right.
This one looks to have 7 digits and no movements, so must be a different model still.
Comes with THREE plugins as well !

A type 549 storage scope as well. Have two of those, hopefully one day I can get one of them going.

Allison hell, I just changed my mind, I will even give you 50 bucks for the lot, how about that !

[Specmaster]

Has anyone ever seen a calculator like this at all? I can't recall seeing anything like myself.

https://www.ebay.co.uk/itm/313959676347

looks like the one the predator wore on his wrist.

Nah, this ones better.

[nixiefreqq]

I've done a bit of poking and prodding at that NLS DVM I mentioned a few days ago.  After replacing a thyratron tube that was cracked and had vented to atmosphere, I've gotten the stepper relays to run fairly reliably and it seems to measure more or less properly.


One big issue is that the relay contacts are cruddy as it sat unused for an unknown length of time in a basement, so unlike the full display in the picture above, in many instances one or more of the digits doesn't light up.


I'm working on making up a longer video showing the troubleshooting (actually sprung for editing software to try to string clips together for a change), but in the meantime, here is a quickie video showing how to clean the stepper relay contacts using Deoxit and a piece of paper.  They're still not perfect (some skips still), but are a whole lot better than they were a few nights ago.
youtube.com/watch?v=eeJXLf0qoNM

Now to do the rest of them...

-Pat

Ooohhhhhh, now that is some real quality porn right there.....

Do want! Tinkering with that at night with some random electronics youtube vids humming in the background is the dream.


Let that deoxit soak for a bit, the contacts will come good eventually with some excersise.

I want to hear the steppers clicking as the voltage varies. 

That's why we Germans would call this a "Klapperatismus"

It reminds me of an old telephone exchange, wonder if it sounds similar....

There are a few noises that, for me, are very evocative of the past. The Merlin aeroengine is one, Strowager exchanges are another, and then there's ASR33 teletypes.

summer of 1982 spent weeks in the ft bragg dco working on some long forgotten project not directly related to the switch.   the stepper sound would drive you nuts!

don't remember how big bragg was.....but somewhere over 10,000 lines.   for some reason the army used the term dco (dial central office) when the commercial world called them CO's.  but a guy from at&t once told me that the army did not own CO's.........just stinkin' pbx's.

in the busy hour this is exactly what it sounded like.

https://archive.org/details/NarboroughStrowgerTelephoneExchange

[mansaxel]

5440 update:

<snip>

Bedtime or thereabouts now, will ponder on through the week.

Now have nice A3 printouts of the Artek-supplied schematics. This will improve work.

[Vince]

That's indispensable even ! 

I have plan to try and get an old cheap A3 B&W printer solely for that very purpose !
In the mean time I make do with A4 size, or if I am well motivated, two A4 sheets taped together...