Author Topic: Test Equipment Anonymous (TEA) group therapy thread  (Read 20249585 times)

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Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11625 on: June 03, 2018, 10:46:55 am »
I wish I had the room and the air con for a 547 ;)
 

Offline med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11626 on: June 03, 2018, 10:52:00 am »
I wish I had the room and the air con for a 547 ;)

Got the A/C and in the winter I could save on heat.

Room? No problem. Kick the OS-245(P)/U off the cart and hoist up that bad boy, although it would be a tight fit.  :o
An old gray beard with an attitude.
 

Offline Berni

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11627 on: June 03, 2018, 11:22:44 am »
So i have taken on figuring out what went wrong in my Tektronix AWG2041 signal generator.

First thing as usual is have a look trough the service manual for any troubleshooting tips. Flowing the troubleshooting flow chart only got me to a suggested solution of "Replace power supply module". The bastards didn't even give me any pinouts on the PSU or any of the boards even. On top of it they use 0.1 inch headers for a few connections that can be plugged in backwards. Someone already was in here so all the connectors had some stripes painted on to indicate what way around they go back together, but i take photos just in case.

Once i get it out however...good lord. This has to be the most complicated PSU i have ever seen in a piece of test gear. Look at the thing!
Its made up from 12 circuit boards! The heatsink is made from 6 aluminum parts screwed together in various spots. The massive output connector has 22 pins, but also has 3 other power output connectors scattered around. :o





How the hell am i gonna fix this over complicated mess of a PSU without any information about what it is supposed to do even.

Once i got the board out i could start tracing things out a bit. Its quite well designed electrically but not so mechanicaly. I figured out the topology of it and found out they have a solid state soft start cirucit (triac i think) that powers up the unit with 12 Ohm in series with the mains at first. The soft start resistor was blown open circuit so that's why it did nothing at all. Later on that fed a boost converter with a giant toroidal inductor to create the PFC circuit. Turns out the power MOSFET in that circuit measured low resistance across all pins. So this is likely what blew up the soft start resistors. Since the PFC circuit is likely not critical for it to work i simply removed the faulty transistor but put the diode and its heatsink back in so that power would still make it trough the PFC. Power it on...aaand woho i get fans going and a picture on the CRT. I still quickly turned it off afterwards just in case.



So here is the part that broke it all. Its a 2SK1018 N channel MOSFET 500V 13A. It looks like an ancient part so il likely replace it with some modern equivalent.
 

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11628 on: June 03, 2018, 11:45:54 am »
Damn I hate power supplies like that. On a positive note you can usually work out what each board is for rather than trying to divide the supply into modules. Good luck with the fix.

I’ve noticed the cheap Chinese test gear has some pretty simple and excellent performing SMPS in them. Far lower component count leading to easier reverse engineering.
 

Offline med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11629 on: June 03, 2018, 12:09:26 pm »
Holy crap!  :palm: It looks like it was designed by an Engineer who took lessons from Rube Goldberg. 
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Offline Berni

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11630 on: June 03, 2018, 12:30:30 pm »
Yeah im grateful its just a PFC problem as i would not want to troubleshoot a complex issue inside the rest of it.

Acording to the label this is a:
Yamanashi Kyosai Denki Ltd.
Model TE-11

So its a Japanese power supply, at least they use Nippon Chemicon caps in it.

Actually all of this thing is made in Japan and the boards inside say "Copyright 1993 Sony/Tektronix". The B/W CRT is of course all Sony.

Its a lovely bit of gear so well worth the effort to fix it with its 1GS/s and 4MB of memory that can be segmented and assembled into even longer sequences or generate 8bit Parallel data out the back of it.
 

Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11631 on: June 03, 2018, 09:39:01 pm »
That’s a perfect quote that sums it up well.

My mantra is about promoting managing complexity along with features and requirements. I am saying I told you so a lot. This is slowly turning into credibility as things go wrong. That’s what software companies look like inside. A giant rug which had dead bodies piled up under it.

On the outside it’s a happy shiny facade of perfection because it’s cheap to pretend.

Anyone want to give me an EE job? :D




mnem
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Offline djos

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11632 on: June 03, 2018, 10:19:27 pm »
They’re both sampling scopes. Real time ones are just faster.

Sampling scopes usually use reconstruction ie they pick samples as quick as possible not necessarily on the same wave cycle to sample say a 20GHz signal. This allows you to build an approximation of a very fast signal if it is repetitive.  Real time ones have stupid fast ADCs and ungodly trickery so they actually sample near the full rate.

So does a digital RTO normally have the ability to capture and review like a normal DSO?

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11633 on: June 03, 2018, 10:44:10 pm »
That’s a perfect quote that sums it up well.

My mantra is about promoting managing complexity along with features and requirements. I am saying I told you so a lot. This is slowly turning into credibility as things go wrong. That’s what software companies look like inside. A giant rug which had dead bodies piled up under it.

On the outside it’s a happy shiny facade of perfection because it’s cheap to pretend.

Anyone want to give me an EE job? :D

mnem
Alternately:


Snipped images. Very true.

This essay always sticks in my mind: https://www.stilldrinking.org/programming-sucks

They’re both sampling scopes. Real time ones are just faster.

Sampling scopes usually use reconstruction ie they pick samples as quick as possible not necessarily on the same wave cycle to sample say a 20GHz signal. This allows you to build an approximation of a very fast signal if it is repetitive.  Real time ones have stupid fast ADCs and ungodly trickery so they actually sample near the full rate.

So does a digital RTO normally have the ability to capture and review like a normal DSO?

Yep. Disclaimer. Only used a very old HP/Agilent unit. Can't comment on new ones but I assume they haven't got any worse as they got faster and more expensive :)

I had to drive one and a modulation domain analyser with 16-bit Visual Basic 4 and HP-IB. As much fun as arse cancer that was.

Honestly I don't know why people bother at those frequencies. I can't think of a single application they can't solve cheaper than an expensive magic scope.
« Last Edit: June 03, 2018, 10:45:42 pm by bd139 »
 
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11634 on: June 03, 2018, 11:42:05 pm »
Oh, that is positively delicious.

I had my time as a youth... back when my brain was still pliant and stretchy like Silly Putty and I could wrap it around such things as nested arrays and hashes and the like... I did some programming in BBX2 and tried to translate that to C++ and tinkered with Python LISP (Python was a later relapse in my 30s) and after a few weeks (was it months?) where the only way I could sleep was to get stoned out of my gourd I eventually wound up stranded in a dry spell and tried to drink the code away...

I had my epiphany in a bathroom stall at a Starbuck's after being politely asked to leave for conspicuously pouring gin in my iced Frappucino and yelling at another patron in line for jostling my arm and almost making me spill it; I dashed away just in time to empty the contents of my stomach on and around the toilet. I realized that I was a few nested parens away from just the sort of madness your author distills perfectly here:

Quote from: stilldrinking.org/programming-sucks
Vast chains of abstract conditions and requirements have to be picked through to discover things like missing commas. Doing this all day leaves you in a state of mild aphasia as you look at people’s faces while they’re speaking and you don’t know they’ve finished because there’s no semicolon.

 Eventually every programmer wakes up and before they're fully conscious they see their whole world and every relationship in it as chunks of code, and they trade stories about it as if sleepiness triggering acid trips is a normal thing that happens to people. This is a world where people eschew sex to write a programming language for orangutans.

I have LITERALLY been this and laughed about it to my girlfriend who got me into programming; she was trouble, I wanted to taste that kind of trouble (and her toes) and she had the best weed; things just took a 40/20 downward spiral from there. When I came to my senses in that bathroom stall, I realized she'd already moved on to another victim, and I was either going to become the freak I saw in the mirror or more likely, WISH I was halfway good enough to be that creepy and get away with it. Knowing that I was fundamentally math-deficient, I decided to go sober up over breakfast at Waffle House and the rest is history.

Not sure if I was lucky or just stupid...


mnem
I took the red pill AND the blue pill. Now we are unanimous.
« Last Edit: June 04, 2018, 05:17:51 pm by mnementh »
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11635 on: June 03, 2018, 11:52:24 pm »
[RANDOM MODE]



Mischief time with the wife's new car:


She was not amused. :-DD

[/RANDOM MODE]


mnem
But she didn't make me take it off until after she'd gone to school and all her coworkers saw it and giggled.   ;)
« Last Edit: June 03, 2018, 11:54:06 pm by mnementh »
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Offline Cerebus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11636 on: June 04, 2018, 01:14:09 pm »
Gentlemen, I'm sorry to report that we have a heretic, a back slider, in our midst. I shall save the apostate's blushes and not name them. However, they acquired some fresh TE at the end of April, refurbished it, and claimed that it was a "keeper". It now transpires that they have listed the same for sale on EBay. That, of itself, is not evidence of apostasy - we all turn over equipment from time to time, that is normal and in full keeping with the sacred tenets of TEA. What is worrying here, and signs of deep spiritual disease, is the phrase found in the middle of that listing's description - I quote:

Quote from: The Heretic
Selling as I'm downsizing my equipment.

Please, as you go about your day, spare a thought for our wayward brother and consider if there is anything you can do to bring him back into the fold.
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 

Offline PA0PBZ

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11637 on: June 04, 2018, 01:21:52 pm »
Still, £36.50 is not bad for a 3478A...
Keyboard error: Press F1 to continue.
 

Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11638 on: June 04, 2018, 01:23:20 pm »
Gentlemen, I'm sorry to report that we have a heretic, a back slider, in our midst. I shall save the apostate's blushes and not name them. However, they acquired some fresh TE at the end of April, refurbished it, and claimed that it was a "keeper". It now transpires that they have listed the same for sale on EBay. That, of itself, is not evidence of apostasy - we all turn over equipment from time to time, that is normal and in full keeping with the sacred tenets of TEA. What is worrying here, and signs of deep spiritual disease, is the phrase found in the middle of that listing's description - I quote:

Quote from: The Heretic
Selling as I'm downsizing my equipment.

Please, as you go about your day, spare a thought for our wayward brother and consider if there is anything you can do to bring him back into the fold.
If the Heretic was me by any chance because I moved on my Fluke 8505A which was a huge boat anchor, than yes, i did downsize it to a HP3478A and some more gear planned that will fit within the same footprint as the 8505A but will actually increase my TE a as result then, I plead not guilty my lord  :-DD
Who let Murphy in?

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Offline Mr. Scram

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11639 on: June 04, 2018, 01:34:52 pm »
Gentlemen, I'm sorry to report that we have a heretic, a back slider, in our midst. I shall save the apostate's blushes and not name them. However, they acquired some fresh TE at the end of April, refurbished it, and claimed that it was a "keeper". It now transpires that they have listed the same for sale on EBay. That, of itself, is not evidence of apostasy - we all turn over equipment from time to time, that is normal and in full keeping with the sacred tenets of TEA. What is worrying here, and signs of deep spiritual disease, is the phrase found in the middle of that listing's description - I quote:

Quote from: The Heretic
Selling as I'm downsizing my equipment.

Please, as you go about your day, spare a thought for our wayward brother and consider if there is anything you can do to bring him back into the fold.
Repenting for a friend?
 

Offline BillB

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11640 on: June 04, 2018, 01:53:00 pm »
If the Heretic was me by any chance because I moved on my Fluke 8505A which was a huge boat anchor, than yes, i did downsize it to a HP3478A and some more gear planned that will fit within the same footprint as the 8505A but will actually increase my TE a as result then, I plead not guilty my lord  :-DD

Increasing TE density seems completely reasonable.   :-+
 

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11641 on: June 04, 2018, 01:54:10 pm »
Guilty party here.

The rationale for the sale is to buy a new TTi 1908 with a USB hole rather than an HP-IB hole. Thus the downsizing is a replacement operation  :-DD
« Last Edit: June 04, 2018, 01:56:52 pm by bd139 »
 

Offline Mr. Scram

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11642 on: June 04, 2018, 02:01:25 pm »
Guilty party here.

The rationale for the sale is to buy a new TTi 1908 with a USB hole rather than an HP-IB hole. Thus the downsizing is a replacement operation  :-DD
I smell a refund because of an inaccurate description coming.
 

Offline GerryBags

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11643 on: June 04, 2018, 02:02:32 pm »
He's selling TEA to make (ugh!) roooooom!


"No, it's ok, he's only making room for more TEA, not aspedistras. Calm down, Don!"

Oh, alright then.
 

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11644 on: June 04, 2018, 02:06:10 pm »
Indeed. I am downsizing. Then upsizing :)

This is merely to ensure that the cash flow situation is water tight against criticism from SWMBO thus avoiding stepping over BOT.
« Last Edit: June 04, 2018, 02:10:26 pm by bd139 »
 

Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11645 on: June 04, 2018, 02:14:07 pm »
Indeed. I am downsizing. Then upsizing :)

This is merely to ensure that the cash flow situation is water tight against criticism from SWMBO.
To do that, you'll have to sell a lot more to make that stick unless you've found a vendor that for a small consideration, give you a receipt for the amount you told SWMBO it cost you but that would be the sale of the century, being all new and shiny and several hundred pounds below the proper price, somehow I doubt that she'd quite swallow that one unless she's a bimbo  :-DD
Who let Murphy in?

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Offline Mr. Scram

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11646 on: June 04, 2018, 02:15:17 pm »
Indeed. I am downsizing. Then upsizing :)

This is merely to ensure that the cash flow situation is water tight against criticism from SWMBO thus avoiding stepping over BOT.
Yeah. As if logic and planning have anything to do with the criticism.
 

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11647 on: June 04, 2018, 02:23:19 pm »
Indeed. I am downsizing. Then upsizing :)

This is merely to ensure that the cash flow situation is water tight against criticism from SWMBO.
To do that, you'll have to sell a lot more to make that stick unless you've found a vendor that for a small consideration, give you a receipt for the amount you told SWMBO it cost you but that would be the sale of the century, being all new and shiny and several hundred pounds below the proper price, somehow I doubt that she'd quite swallow that one unless she's a bimbo  :-DD

Yep got some other stuff to shift as well, not vai ebay. Not getting mugged for fees on larger items. Not test gear either.

My father used to do that to my mother. one of the reasons he always kept the boxes for everything afterwards; to make a point that stuff could look new that wasn't :palm:. She wasn't stupid.

To be fair as much as I join in the banter, she's OK with this sort of stuff because it's well under control. If only this was reciprocal :(
 

Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11648 on: June 04, 2018, 02:24:59 pm »
Indeed. I am downsizing. Then upsizing :)

This is merely to ensure that the cash flow situation is water tight against criticism from SWMBO.
To do that, you'll have to sell a lot more to make that stick unless you've found a vendor that for a small consideration, give you a receipt for the amount you told SWMBO it cost you but that would be the sale of the century, being all new and shiny and several hundred pounds below the proper price, somehow I doubt that she'd quite swallow that one unless she's a bimbo  :-DD

Yep got some other stuff to shift as well, not vai ebay. Not getting mugged for fees on larger items. Not test gear either.

My father used to do that to my mother. one of the reasons he always kept the boxes for everything afterwards; to make a point that stuff could look new that wasn't :palm:. She wasn't stupid.

To be fair as much as I join in the banter, she's OK with this sort of stuff because it's well under control. If only this was reciprocal :(

Did't you get the £1 offer valid for yesterday and today only?
Who let Murphy in?

Brymen-Fluke-HP-Thurlby-Thander-Tek-Extech-Black Star-GW-Avo-Kyoritsu-Amprobe-ITT-Robin-TTi
 

Offline Mr. Scram

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #11649 on: June 04, 2018, 02:26:10 pm »
Yep got some other stuff to shift as well, not vai ebay. Not getting mugged for fees on larger items. Not test gear either.

My father used to do that to my mother. one of the reasons he always kept the boxes for everything afterwards; to make a point that stuff could look new that wasn't :palm:. She wasn't stupid.

To be fair as much as I join in the banter, she's OK with this sort of stuff because it's well under control. If only this was reciprocal :(
Maybe you can secretly cut her hair and trim her nails every time she sleeps. That way she won't need to go to a salon any more. She'll be happy, you'll be happy. Right?
 


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