Author Topic: Test Equipment Anonymous (TEA) group therapy thread  (Read 15736237 times)

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Offline TERRA Operative

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132400 on: December 16, 2022, 05:46:43 pm »
I'm currently poking away at the Option board I built for my Tek AWG5101 Arbitrary Function Gen, and I'm not sure it's working right....

I'm thinking the MC145145 4–Bit Data Bus Input PLL Frequency Synthesizer chips I bought from China are shit...

I've found a seller on ebay that apparently has MC145145P1 chips for a not stupid price (I'd rather the slightly better MC145145P2 version, but whatever) so I might grab some to check against the Chinese ones..


Does anyone have some spare MC145145 chips around by chance? :D
Where does all this test equipment keep coming from?!?

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132401 on: December 16, 2022, 07:00:24 pm »
Should be un-bΦrked now, I re-uploaded the picture.
 

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132402 on: December 16, 2022, 07:08:43 pm »
And while fixing the Systron Donner SA I obviously needed a signal generator. Which, eh, made a HP 8350B along with a nice 2-18.6 GHz plugin follow me home from a ham fair.  :-//

Some cleaning, a new battery pack to feed the settings NVRAM,  some metal work to firmly attach the plugin and its adapter together and things are A+ OK.
Note to former owner: duct tape is not what HP ordered to join plugin and plugin adapter  :palm: Oh, and I did an adjustment per the nice service manual.

Wilko
 
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Online wkb

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132403 on: December 16, 2022, 07:16:21 pm »
[ Specified attachment is not available ]On its way is something that would (probably) have been very useful when I was repairing a couple of Hp 5342A microwave counters. In other words: I bought a HP 5004A signature analyser. Chances are I will never need it but he,,,

Hm.. maybe I need to get a TEA / anti-GAS vaccination?

Wilko

« Last Edit: December 17, 2022, 09:53:27 am by wkb »
 

Offline Vince

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132404 on: December 16, 2022, 07:46:55 pm »
Your pics are borked again.... as Robert said, better to skip the first attachment when you upload your pics.

The pic of your last message doesn't show up at all here, and in the message before that, the first of the 3 pics has a problem too : what you get when you click on it, and the thumbnail.... don't match.

 
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Offline Neomys Sapiens

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132405 on: December 16, 2022, 09:36:11 pm »
The pic of your last message doesn't show up at all here, and in the message before that, the first of the 3 pics has a problem too : what you get when you click on it, and the thumbnail.... don't match.
What you see there is the signature analyser from the latter post.
 :D
 
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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132406 on: December 17, 2022, 09:57:29 am »
This getting bloody annoying, it looked OK on the iPad I posted it from.  :horse:
I redid the uploads, appears to be correct now. But who am I in this context.  :palm:
 

Offline Vince

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132407 on: December 17, 2022, 10:28:44 am »
Nope still doesn't work for me here. Same problem persists, the first of the 3 pics is borked, thumbnail and full pic don't match.

Here is what I see when I click on the first thumbnail. The thumbnail shows a part of a front panel, but this is what I get instead :




 

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132408 on: December 17, 2022, 10:34:28 am »
1666153-0

This is what I get.  For good measure the iPad has been power cycled.

 :wtf:
 

Offline McBryce

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132409 on: December 17, 2022, 11:18:46 am »
This was all discussed before. The solution is to always leave the first attachment box empty, ie: When you open the attachments drop down, don't put any file in the first box. Click "(more attachments)" and put the first picture in the box that appears below the first box.

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Offline Vince

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132410 on: December 17, 2022, 01:33:24 pm »


OK the suspense is over... the next piece of TE on the bench is not the Philips VTVM but... the Rochar DMM I bought the other day.
Best 10 Euros I spent in a long time, talk about a bargain. The two ones on Ebay went for like 150 Euros !  :scared:


CONDITION

Mine looked rough for sure, but turns out it was just dust, saw dust I would even venture to say. It cleaned up very well and very easily.
The front of Rochar instruments is a delight to clean : the face plate comes off iun seconds : just 43 screws in the corners, and it comes off ! All the controls, switch gear, fuse holders.... nothing needs to be taken, off. The bezel also comes off easily. So it's quite easy to clean thoroughly.
3 white round stickers on the face plate also came off easily.

The design of the enclosure is everything but air tight at the rear, so lots of small debris entered the instrument. Had to remove the top and bottom cover and shake the thing at length to get the crap out of it.
But, other than this, the inside is spotless. Hardly a spec of dust, zero corrosion, it looks nearly new. An excellent surprise !

Looks really nice inside out now  8)

Mechanical-wise, there are a few dings at the back, which you can't even really see on pictures, don't even feel the need to do anything about it, it's minor.
The most visible is the one I have already shown in a previous message : front right corner of the top cover is a bit out of shape. Not enough to spoil the fun, and is probably fixable.


CONSTRUCTION

The unit belonged to Aerospatiale according got stickers, and was fitted with an hour counter. My unit looks like it ran for only 5,021 hours which is not much eh ?

Back plane has fat gold plated traces like the HP stuff of that era.
The boards are held by two brackets front and back. Removed them so I could take pics of the back plane and board for you. Big mistake.
One of the screws holding the brackets fell under the bench... I managed to recover it but the star washer that was with it  :-\
Then when you lift the brackets.... bit fall inside the instrument, need to dive to recover them... looking closer... these bits are small slotted plastic guides that hold the boards, grabbing them from the edge. All these guides are glued onto the metal brackets, but the glue has dried and many of these guides are now free electrons, and putting everything back together is a chore, one can easily lose his sanity of this.
So I really need to re-glue these guides... super glue I guess might be all that's needed.

Display boards : their construction is interesting... I mean the tube part in particular. The tubes are no socketed. They don't even have a plastic base with round pins to begin with. No, all you have are the barre thin wires that come out of the glass envelope of the tube, and these wires are soldered onto a tiny PCB, which is then mounted onto the display board, into a slot, at a right angle. So, very customs.
This means that the tubes are just "floating" onto their wires, hence it's impossible to get them to sit straight and all aligned. They are all crooked... so it's gonna stay like that. I will just declare it's part of the charm f this meter.... when you can't change something, instead just change the way you look at it...  ::)


ELECTRICAL TESTING

Out of the box, it appears to work quite well !
The main frame is alive, and when I use the Voltmeter part of the plug-in, it works out of the box and reads surprisingly accurately when I feed it with my cheap chinese Vref that outputs 2.5 / 5 / 7.5 /10 volts. It reads just 2 or 3 counts above perfection. Like, 2.503V or 10.002V, something like that. More than happy with that.

BTW, that range switch suggests it's a 20,000 count meter, but the mainframe actually can counts up to 25,000 and will only light up the "overload" light when going past 25,000 not 20,000.
Measurements made between 20,000 and 25,000 look just as accurate to me as those below 20,000... so I will declare this a 25,000 meter if you don't mind ! >:D

There is a " Check 20,000 " calibration position on the plug-in switch. I adjusted it spot on but it makes the meter read a tad low now, like 2,495V instead of 2.5. So I guess that means the internal Vref in the plug-in is not as accurate as my chinese Vref, so I decided to use the Chinese Vref instead, to calibrate the full scale. Sue me.


ISSUES


So overall it's a one hell of a buy for the money, I am extremely happy with purchase. But of course it's not perfect, so here is what I found that needs fixing...

1) Like any Rochar TE, the orange colour filter in front of the display tubes, is dropping, doesn't stay in place. That's because it's held in place by strips of foam glued onto the chassis, that push the filter against the back of the face plate. Foam deteriorates of course and just can't hold the filter any longer.
I have already fixed that in another piece of Rochar TE of mine (my universal counter) : pull the remains of the old strips, clean the glue residue, and apply some new strips of foam... so I did that, except I could not find my roll of foam... the "garage" part of my living room is too much of a cluster fuck, not much is accessible.... I quickly gave up. I will stumble upon it one day, but in the meantime I just used masking tape ti hold the filter onto the chassis.... does the job for now.... :-//


2) The 4  little neon bulbs used for the decimal points on the display, look pretty dim and tired. One in particular : number 2 from the left. It looks even dimmer than the other 3, and sometimes doesn't even come on at all. sometime it does, but very dim and in the course of a few seconds it becomes dimmer and dimmer and dimmer and... eventually turns off altogether.   Now whether the bulbs themselves are tired, or the electronics driving them is faulty... I don't know just yet, need to investigate !  ;D   


3) The most problematic issue now : the ammeter part of the plug-in is very sick. As much as the voltmeter pat is excellent... the ammeter part is sick.
With no current supplied to its inputs, on all ranges it reads something ! From cold it's a relatively small but not insignificant value. I decided to test the plugins anyway and fed some current using my current limited lab power supply. This allowed me to test the two highest ranges : 2A and 200mA. They appear to work just fine and accurate, I was pleased. Disconnected inputs. Then after a few minutes the "no input" value displayed on the main frame would got up and up and up and up ! For example the 2A range would happily display 1.2A ... no kidding. After a few minutes it went over the top and most if not all ranges simply overloaded the display : " 25,000 overload " is what I would get.

I noticed that the input fuse and its socket were bad lt corroded, lot of green stuff. I fixed that. No joy.

So basically this ammeter is haunted.
So it's unusable as is. Need to fix it.... but I don't have a manual for it. Electropuce has the manual for the mainframe, but the mainframe appears to work just fine. It's a manual fo the plugin that I need, and Electropuce I think doesn't have one  :(

I will google a bit see what I can find.

Maybe I stand a chance of fixing it without a manual ? I mean the ammeter is obviously just shunts that then feed the voltmeter part... and we know that the voltmeter works just fine. So there is not a whole bunch of circuitry that could potentially cause our problem here, I guess.
From cold it measures OK, so the basic functionality and current shunts are most likely OK.
So the problem must lie in the small piece of circuitry that's at the interface between the Voltmeter part and the current shunts of the ammeter.

The "ghost" measurements appear only after a few minutes and get worse and worse... so maybe there is a capacitive effect here, some old cap that leaks, and that leak causes trouble in the circuitry, in some way as to create a false reading, that gets higher and higher as time passes.
I don't know....

Anyway, something to investigate/ troubleshoot, that's cool.
Overall extremely happy with my 10 Euro purchase !!!  :D

Now some pics...
« Last Edit: December 17, 2022, 01:54:02 pm by Vince »
 
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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132411 on: December 17, 2022, 01:36:26 pm »
This was all discussed before. The solution is to always leave the first attachment box empty, ie: When you open the attachments drop down, don't put any file in the first box. Click "(more attachments)" and put the first picture in the box that appears below the first box.

McBryce.

OK, not something that I had noticed, but I
am only a semi-regular on this forum

Making a mental note..
 

Offline Vince

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132412 on: December 17, 2022, 01:36:26 pm »
....
 

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132413 on: December 17, 2022, 02:38:51 pm »
Todays work was adjusting a HP 8116A 50MHz Function/Pulse Generator.

It all adjusted ok (Holy hell these things need some tweaking! Following the procedure has you going in circles tweaking the trimpots around and around to narrow down the adjustment) so now it's on the 'to sell' pile.

I still need to find one of the unobtanium 1DD6-0002 chips for the other 8112A though, it seems to work ok besides that (stupid fan died and let the custom chip overheat...)
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Offline Vince

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132414 on: December 17, 2022, 03:19:15 pm »



Quick project / repair of the week-end : just received a DMM from the old man.

He never used it, a spare he pinched from work.

Said it doesn't work and asked if I fancied a repair challenge.... well ye sI do. It's a nice little meter.

A Chauvin-Arnoux CA5220.

It's not for electronicians, it's for electricians in the field. Not so accurate, but plenty accurate enough for what it's meant for. Simple, rugged, compact... it's great for general electrical work in our outside the house. So it's in the same spirit as my Fluke 11 except the Chauvin-Arnoux can measure current, frequency, and has a backlight. So I would not mind having it in my toolbox...

So, problem from what I can see is that it does not even power up. Given that it's not been used for the past 25 years as I understand it... I cracked it open to most likely replace the batteries and witness potential corrosion damage. None of that : inside; there are no batteries, no corrosion... and no battery holder ! I can even fit batteries in this DMM !  The two wires black and red going to the holder when it used to be there... have been cut !  :palm:

So....I stripped the two wires and powered the meter using my lab supply set on 3Volts.

The meter now powers up just fine. Tested it : it's kaput. No matter what voltage you throw at it, it will register only 88mV tops. Same for current : no matter how many amps you shove into it, the max it will register is a few mA !  ::)  I guess the two problems are related if not the same : it can't read voltage hence it can't read the voltage drop across the current shunts either. So the fault probably is a blown front end, in a part that's common to both volts and amps signal paths.

I guess someone decided that since this meter was kaput, he might as well use it as a parts unit and steal the battery holder from it ?!  :-//

Pffff...

So just for the fun of it, I will spend a couple hours buzzing the front end to see if I can see a blown component and fix it. No schematics to be found I assume, so I will just mass buzz everything on the board, hoping to get lucky... knowing that it's pointless since even if I can fix it, I still would not be able to use the meter anyway, due to the lack of battery holder. Maybe I could hack something ? Don't know... not much space in that molded plastic case for anything but what used to be designed to fit in there....  :-\



 

Offline Vince

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132415 on: December 17, 2022, 03:25:41 pm »
Edit : just googled, found a pic of what the battery holder in this thing looks like. It looks to me like a pretty standard / off the shelf kind of holder no ??

Maybe I can buy one like that somewhere...for cheap.

OK so maybe it's worth trying to fix that one...

« Last Edit: December 17, 2022, 03:50:01 pm by Vince »
 

Offline Vince

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132416 on: December 17, 2022, 03:42:41 pm »
EDIT #2 : old man just admitted HE ripped the battery holder to fix another meter !  :blah:
He sent me a picture of the remains of the broken holder he replaced.

He confirms it's a standard holder and he just found one like it on Ali Express for only 1.50 Euro delivered.... great,

So now this meter is worth fixing...

I will e-mail Chauvin Arnoux see if they have schematics. They are often nice to private individuals and will send information if they have it.

« Last Edit: December 17, 2022, 03:49:32 pm by Vince »
 

Offline Robert763

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132417 on: December 17, 2022, 03:54:58 pm »
Hi Vince,
Check the input resistance with another meter. If it's not 10M you may have an open circuit selector or cracked PCB. Also check for shorted overvoltage protection components.

Robert G8RPI.
 
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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132418 on: December 17, 2022, 04:02:16 pm »
And I assume you already checked the fuses aren't blown? :-DD
Where does all this test equipment keep coming from?!?

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Offline Vince

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132419 on: December 17, 2022, 05:17:38 pm »



Thanks for the suggestions Robert and Terra.

Terra, yes, I did check the fuses !  >:D


Good news : it's already fixed, ot hell with schematics !  I got lucky and mass buzzing got me somewhere.

I checked every resistance in sight, they all measured fine. Then check the 4 trimmers.

The two 10K and the 22K one checked OK, but the fourth and last one, marked 170K, did not... it read 280K ! Not possible in circuit...
So was probably open circuit. I removed it from the board so I could test it better. Appears to work fine and smoothly, but somehow the resistance of the track read almost half a meg, 3 times what it should be. Weird. A bit of drifting OK? but 300% more uh.....  :-//
Looking at traces on the PCB, it appeared the trimmer was wired as a mere variable resistor rather than a potentiometer.
So I looked at the angular position of the wiper, deduced what resistance the trimmer OUGHT to offer... then adjusted the wiper so that it ACTUALLY offers that value, soldered it back to the board and... meter now works perfectly !!!  :-DD

Every function works fine and reads correct. Capacitance, diode test, amps, volts, ohms.... all of a sudden everything is fine !

Gee if only all repairs could be like this ! Less than an hour, and not even a schematic !

I just got meself a nice DMM to throw in the toolbox  8)

« Last Edit: December 17, 2022, 05:22:23 pm by Vince »
 
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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132420 on: December 17, 2022, 05:44:47 pm »

Gee if only all repairs could be like this ! Less than an hour, and not even a schematic !

I just got meself a nice DMM to throw in the toolbox  8)
Don't get too attached to it Vince as it seems way short of much in the way of input protection although if you're careful using it, it could likely see you out.  :-\
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Offline Vince

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132421 on: December 17, 2022, 06:14:26 pm »
Chauvin Arnoux is a leader here for industrial field electrical equipment, this meter is a standard for pro electricians. It's just fine.... I won't die when checking for mains presence when fitting the light fixture in the house... I am not worried...
 

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132422 on: December 17, 2022, 06:20:43 pm »
Chauvin Arnoux is a leader here for industrial field electrical equipment, this meter is a standard for pro electricians. It's just fine.... I won't die when checking for mains presence when fitting the light fixture in the house... I am not worried...
I know. I know.  ;)
When you've watched lots of Joe Smith's vids on poorly protected DMM's you might see things differently.  ;)
Just saying.....
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Offline Vince

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132423 on: December 17, 2022, 06:33:42 pm »
I am always accused of dramatizing.... I think this time it's you dramatizing. If you think electricians risk their life with a reputable brand, just think what of the millions of people that use dirty cheap chine meters. They are much more at risk than all the pro electricians using their Chauvin-Arnoux mete day in day out for a living.

I am sure I can find videos of Fluke meters failing in nasty ways. If you search long enough, you can always find a counter example to anything...

I do appreciate though, you showing interest in my well being. It's heart warming. Must be the X-mas effect.

I do have real problems right now, and they have nothing to do with meter safety. The kitchen sink is blocked, water won't drain at all. Somehow it seemingly happened overnight, strange...
That has me much more worried than using this "dangerous", life threatening meter...

Ballantine TRMS VTVM just been put up for sale online, let's see if anyone in this world show any interest.... probably not.

EDIT : I was wrong. The ad has been online for only 25 minutes but apparently 6 people have already clicked on the ad....
« Last Edit: December 17, 2022, 06:40:11 pm by Vince »
 

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #132424 on: December 17, 2022, 06:48:23 pm »
I am always accused of dramatizing.... I think this time it's you dramatizing. If you think electricians risk their life with a reputable brand, just think what of the millions of people that use dirty cheap chine meters. They are much more at risk than all the pro electricians using their Chauvin-Arnoux mete day in day out for a living.

I am sure I can find videos of Fluke meters failing in nasty ways. If you search long enough, you can always find a counter example to anything...

I do appreciate though, you showing interest in my well being. It's heart warming. Must be the X-mas effect.
;D
So you haven't followed Joe's videos on how robust is your DMM ?
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/
The backstory is the interesting part as a lot of the world isn't affected from the static electricity Joe seems to have that's killed a few of his early DMM's so as we often do Joe went to find out why and deep into a special rabbit hole to test many DMM's to see how actually robust against static they were.
Lots of very interesting failures were found along the way like the susceptibility to magnetics of a Gossen Metrawatt DMM.
In the very moist climate we have it's not an issue and I've not lost a DMM to other than my own incompetence but now I own a cheap Chinese market Fluke for little more than for piece of mind.

« Last Edit: December 17, 2022, 06:57:20 pm by tautech »
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