Test Equipment Anonymous (TEA) group therapy thread

[tggzzz]

Nice KVD though. I have the seven decade version (VDR106/7) in the wooden case. I paid £0 for it. Basically just had to convince the previous keeper that I knew what it was and how to use it. More reliable than the Fluke 720 due to no presets  and much simplier switching. Calibration check is every 5 years (for 1ppm) and just needs 11 reasonably well matched 10 k resistors. A method recognised by the NBS as more accurate than direct comparison to their primary standard voltage divider.

That's annoying: now I "need" to calibrate mine. Any refs to the method?

The only test I've done is to see the linearity of the VDR106/7 and Solatron 7081 combination. IIRC it was mostly <1ppm, with one value being 1.5ppm out.

Given my poor technique, that's good enough

[factory]

Geez, just back from work, checking Leboncoin.fr , what do I see ?! FRUSTRATION !! Nothing but ... FRUSTRATION !

I just got that 502A last week-end, 75 Euros for a rough one, and today there is another 502A, mint looking for only 25 Euros ! But local pick-u only of course, and of course seller is at the other end of the country ! 

https://www.leboncoin.fr/collection/2251203109.htm


Then, even worse....

That really nice Rochar Neeksee DVM Factory just found, that I have never seen before, guess what ? YES, one just popped here today ! You just can't make that up ! And only 5 Euros as well, not the usual 100/150 BS !! BUT !!!.... the title of the ad says it's reserved for some guy by the name of " Rémy " already !!! 

https://www.leboncoin.fr/collection/2251260020.htm

Same problem here, anything listed that low on ePay, disappears very quickly while I'm at work, but then again I have way too much TE here waiting to be repaired. Oh mine was in your BS price range, had to bid for it.

And the TE at work has slowly been disappearing into "Sims" scrapmetal cubes. They finally let me fill in a scrap request form last month, then I waited patiently for them to decide a price, only to be told two weeks later I couldn't have any of it, not for any amount.
"Sims" are one of the worst waste/scrap companies, they will almost certainly shred everything, plus it's left outside on the car park to get rained on for weeks before it gets taken away.  I only wanted a couple of things, including the Rotek.

David

[Vince]

Wow every time you write about your company, it looks like they really suck big time ! Scrapping stuff rather than letting people have it, even if paid for, how mean is that !

[Vince]

Glad it worked for you Vince.
The control isn't really exponential, it just starts at about a third of the travel of the pot. If you put a 2k7 or 3k3 resistor between the potentiometer CCW end and common you will get a better range of control over the mechanical range of the potentiometer. (minimum gate voltage will be about 2.5 to 3V)

I played with that. Added a 2.7k resistor, minimum Vgs rose to 1.7V IIRC.   
Tried a 3.3k instead, now 2.0 V.
Still a bit far from the threshold, but much better.
The battery is a bit low, reads 8.0V, which might explain why...
Also I don't want to increase the resistor value too much for fear that with a health battery I might end up a tad ABOVE the threshold, and be unable to turn the load off 100% ! That would be embarrassing !

So I left it at a 2.0V minimum voltage.

Then I switched gear juice-wise. I wanted to test the load outside of my immediate needs, i.e. above 5 amps. Wanted to load test the.... load, see how it behaves, if it catches fire, melts the heat sink or whatever...

So I gave up my adjustable lab power supply and instead found an excellent excuse to give my old " Adtech Power " PSU a ride ! Remember I featured it on TEA a few months ago... you commented on it, saying good things about it 
It can do +/- 12V at 3A.... not good enough here. But the 5V output is good for 12A says the sticker on it !

So I tried that.... the load worked just fine. It could do 10A and maintain it no problem. Heat sink was still far from overheating, I could still maintain contact with my hand permanently without having tears coming out of my eyes.

I got 10A with only 5V at the gate ! OK, having three MOSFETs in // helps I guess 
Then I cut the power and kept winding the pot to see how much headroom I had left. I still had 5 more turns to go, I was only at 50% !
So yeah, I have plenty of room to adjust things to increase my angular resolution / accuracy quite a bit, if I limit the gate excursion to say 6V ! 
Maybe I could improve the circuit by adding a 6V+ Zener diode to supply the pot. This would make it insensitive to battery condition and let me fine tune the resistor to safely optimize the minimum gate voltage. guess I could replace that fixed resistor with a little adjustable one, simply.

Hmmm....


So, I think I have tested my load well enough.
It can do large currents up to 10A no worries and not explode, it's a winner ! 

Also, it was just as much about load testing my old Adtech PSU ! I mean it's old and no idea of its condition. When I tried loading it the other day with a fixed power resistor, the most suitable I had in stock looked real beefy but still was nowhere near good enough apparently, given that in seconds its terminals melted !!! 

So now, I know that this venerable PSU can maintain 10A out of its rated 12A, fingers in the nose ! 

I would have tried testing it, and my load, up to the full rated 12A but.... all my DMM stop at 10A.... all but ONE !

My cool little WaveTek DM27XT LCR meter can do 20A !
So I tried it, only to find out that the amps range is kaput ! With no leads connected to it, it displays 0.8A on the screen ! 

So I guess I have one more TE in the repair queue then !

Hopefully it's something simple.... I really like this DMM, I bought it to use it, not to keep it i storage advitam eternam....

It's so cool, now I can test any PSU even super beefy ones, properly, easily, accurately, at the touch of a pot... for ZERO Euro spent, only a handful of salvaged parts ! It doesn't get any better than this ! 


OK so next step, tomorrow... build Zoli's load !  The power part is now sorted out, heat sink, MOSFETs, precision pot.... ready to use. I only need to connect that to Zoli's board and I will be in business I think ! 

[m k]

Wow every time you write about your company, it looks like they really suck big time ! Scrapping stuff rather than letting people have it, even if paid for, how mean is that !

It's possible favoring, internal affairs and company policy.
May somebody from outside is a better bidder.

[Robert763]

Nice KVD though. I have the seven decade version (VDR106/7) in the wooden case. I paid £0 for it. Basically just had to convince the previous keeper that I knew what it was and how to use it. More reliable than the Fluke 720 due to no presets  and much simplier switching. Calibration check is every 5 years (for 1ppm) and just needs 11 reasonably well matched 10 k resistors. A method recognised by the NBS as more accurate than direct comparison to their primary standard voltage divider.
i scanned it and put it on Did

That's annoying: now I "need" to calibrate mine. Any refs to the method?

The only test I've done is to see the linearity of the VDR106/7 and Solatron 7081 combination. IIRC it was mostly <1ppm, with one value being 1.5ppm out.

Given my poor technique, that's good enough

I scanned it and put it on Didier's (KO4BB) site
http://www.ko4bb.com/getsimple/index.php?id=download&file=06_Misc_Test_Equipment/Julie_Reasearch_Labs_VDR1067_VDR307_Kelvin_Varley_Voltage_Divider_Operator_Manual.pdf

Robert.

[m k]

Here is why sending a new one would be best, cannot remove the last wire. 


Seems the AVO DMM uses the same DIN connector for the DC power input, as the Advance DMM2, this one came with the AVO, pictures attached.

David

You mean the screw head is off and everything of the rest is molded together.
Can you "hammer" it?
Other side has a shoulder so you can but bushing against it and "hammer" the screw from other side, and maybe break the oxidation.
Heating a pin and cold spraying the screw feels more difficult, maybe freezing the wire would do something.

What would be the right oxidation remover, a carburettor cleaner?

For DIN connectors,
I've pretty much avoided them all since practically everything in that area of my world have been some sort of plugs.
What I have are sort of DINs for sort of alternative uses, like a power brick and its PCB part, but of course their genders are wrong way.

One other thing, when ordering those Fluke connectors from Mouser I forgot those 2AG fuses.
But not a biggie, better change the holder to 20mm version anyway.
2AG from Mouser was >4€ each, local Farnell offers exactly one version for >2€ each + 25€/order + other addendums.
On the other hand, I didn't check the current holder carefully enough, maybe it has open ends.
What we learned, or relearned here, do not close the case too early.

Few comments about the recent PSU.

Are we agreeing it's a minimalistic adjustable SMPS of early day's style?
With or without being from eastern block.

Anyway, I think I understand the circuit now, thanks to one Mullard document.
Center tapped part is horizontal and diode part vertical shift of control voltage.
Since horizontal shift can't go backwards just a simple vertical attenuation of positive side will prevent misfiring, and adjustable value there will take care of all component tolerance issues.

BTW,
when cleaning that power-on lamp I didn't try to screw it in first.
Now leaving it out a bit is the intention.

BTW2,
still can't find that earlier expensive Belling Lee page, just checked the whole browsing history.
The picture is very clear in my mind, it was even named as just Lee.

[Robert763]

Wow every time you write about your company, it looks like they really suck big time ! Scrapping stuff rather than letting people have it, even if paid for, how mean is that !

It's possible favoring, internal affairs and company policy.
May somebody from outside is a better bidder.

More likely typical British accounting  & "legal" mangement  "cover my ass". If they scrap it they have no liability, no chance of being accused of wrong doing etc.  Easy and no brainer. They don't care about the waste.
If they let you have somthing and you electrocute yourself with it your family might sue them.
Not uncommon. I know companies who will let staff have unwanted office furniture etc but nothing with a plug on it or any kind of tool.

[Neomys Sapiens]

I have managed to get an identical SOAR pen multimeter like the one with the broken battery contact spring for my small kit. I will nevertheless keep my eyes open for a suitable piece of material so that the old one could be revived. There would be enough interested persons already around me, so if it could be done with justifieable effort, it would make someone happy. But most important, my small carry kit is complete again!

[Neomys Sapiens]

Wow every time you write about your company, it looks like they really suck big time ! Scrapping stuff rather than letting people have it, even if paid for, how mean is that !

Unfortunately, it is rather the norm  that the exception. At one place of work, I pulled about 60 4mm Pomona shorting plugs out of the scrap container - of the same type of which we had just ordered about 100 pieces. I kept them.
Also MiniCircuits mixers and some other nice parts.
When I returned to the magical container with a friend some days later, everything was locked up. And on top of the full parts container I saw - unmistakable even outside the cage - a handful of Jennings vacuum relays. Arrrgh!

[factory]

Wow every time you write about your company, it looks like they really suck big time ! Scrapping stuff rather than letting people have it, even if paid for, how mean is that !

It's possible favoring, internal affairs and company policy.
May somebody from outside is a better bidder.

More likely typical British accounting  & "legal" mangement  "cover my ass". If they scrap it they have no liability, no chance of being accused of wrong doing etc.  Easy and no brainer. They don't care about the waste.
If they let you have somthing and you electrocute yourself with it your family might sue them.
Not uncommon. I know companies who will let staff have unwanted office furniture etc but nothing with a plug on it or any kind of tool.

Yes those in charge they don't care about waste, they just want the room clearing for reuse. Some of the kit is almost brand new or new (spares for other departments, or bought in error), the rest ancient. It's not just electronic/electrical TE, also mechanical measurement equipment, all rusting away in the skip I have to see every day till it gets collected. If they had any brains they would dump it with a commercial auction house.

David

[Neomys Sapiens]

But it can sometimes work the other way round too. At another company, a well known dealer in second hand parts and electronic 'scrap' (with whom BU508a does a lot of business, and who is a bit of a cutthroat) gets anything they want to dispose of. That was intended to be the fate of the two pick-and-place machines too which were not needed anymore.
Well, they put them in the parking lot on a nice summer evening without any note to them ...
Between me and one other co-worker, we had stripped them of motors, cameras, light guides, connectors and as much parts as we could carry. When Mr. H. arrived on the next day with a car plus trailer to retrieve them, he did not seem happy about what he saw..
 

[factory]

Left a few bids on the junk at PP auctions, they won't let me buy a Rotek either, think "skycontrols" is controlling the prices to make sure there are no bargains (it's in the T&Cs as we found some time ago).

David

[factory]

Here is why sending a new one would be best, cannot remove the last wire. 


Seems the AVO DMM uses the same DIN connector for the DC power input, as the Advance DMM2, this one came with the AVO, pictures attached.

David

You mean the screw head is off and everything of the rest is molded together.
Can you "hammer" it?
Other side has a shoulder so you can but bushing against it and "hammer" the screw from other side, and maybe break the oxidation.
Heating a pin and cold spraying the screw feels more difficult, maybe freezing the wire would do something.

What would be the right oxidation remover, a carburettor cleaner?

For DIN connectors,
I've pretty much avoided them all since practically everything in that area of my world have been some sort of plugs.
What I have are sort of DINs for sort of alternative uses, like a power brick and its PCB part, but of course their genders are wrong way.

One other thing, when ordering those Fluke connectors from Mouser I forgot those 2AG fuses.
But not a biggie, better change the holder to 20mm version anyway.
2AG from Mouser was >4€ each, local Farnell offers exactly one version for >2€ each + 25€/order + other addendums.
On the other hand, I didn't check the current holder carefully enough, maybe it has open ends.
What we learned, or relearned here, do not close the case too early.

Few comments about the recent PSU.

Are we agreeing it's a minimalistic adjustable SMPS of early day's style?
With or without being from eastern block.

Anyway, I think I understand the circuit now, thanks to one Mullard document.
Center tapped part is horizontal and diode part vertical shift of control voltage.
Since horizontal shift can't go backwards just a simple vertical attenuation of positive side will prevent misfiring, and adjustable value there will take care of all component tolerance issues.

BTW,
when cleaning that power-on lamp I didn't try to screw it in first.
Now leaving it out a bit is the intention.

BTW2,
still can't find that earlier expensive Belling Lee page, just checked the whole browsing history.
The picture is very clear in my mind, it was even named as just Lee.

Yes the screw head is missing, wasn't there when I opened it to remove the oversized cable and the pins are molded in place as you guessed. I wondered if I could drill it out and solder the wires in, but would need to use a socket to keep the pins from moving about. But I have a couple of good leads already.
Do you need some cable to go with it, needs quite thin stuff?

David

[vk6zgo]

Should between £3.25 to £4.60, depending on packaging thickness & weight, need to find something suitable.

Here is why sending a new one would be best, cannot remove the last wire. 


Seems the AVO DMM uses the same DIN connector for the DC power input, as the Advance DMM2, this one came with the AVO, pictures attached.

David

That screwdriver in itself, is getting to be a collector's item!

[BU508A]

But it can sometimes work the other way round too. At another company, a well known dealer in second hand parts and electronic 'scrap' (with whom BU508a does a lot of business, and who is a bit of a cutthroat) gets anything they want to dispose of. That was intended to be the fate of the two pick-and-place machines too which were not needed anymore.
Well, they put them in the parking lot on a nice summer evening without any note to them ...
Between me and one other co-worker, we had stripped them of motors, cameras, light guides, connectors and as much parts as we could carry. When Mr. H. arrived on the next day with a car plus trailer to retrieve them, he did not seem happy about what he saw..
 

"a lot of business" 
I'm very picky but I have to admit, that from time to time he has some interesting offers.
Last example: https://www.eevblog.com/forum/chat/what-did-you-buy-today-post-your-latest-purchase!/msg4502476/#msg4502476
  

[Ice-Tea]

Left a few bids on the junk at PP auctions, they won't let me buy a Rotek either, think "skycontrols" is controlling the prices to make sure there are no bargains (it's in the T&Cs as we found some time ago).

David

Under 'factory'? I'll do my best not to outbid you

Also: yes, probably skycontrols this time...

[TERRA Operative]

Awwwwwwwwwww





yiss




(Showing 6kHz output from my Tek SG505 Oscillator)

[tautech]

How long will it stay as SSA3021X Plus ? 

[TERRA Operative]

Just long enough to make sure there are no warranty issues, then it's VNA time!

I already unlocked the options just now, as is tradition.

[tautech]

Just long enough to make sure there are no warranty issues, then it's VNA time!

I already unlocked the options just now, as is tradition.

Yeah get to know it some a bit first before having so much more to get lost in investigate. 

Chap visited today and spent nearly 2hrs in front of our SVA1032X and loved it but he's a field RF transmission tech so was really interested in the newly spotted SA/VNA handheld instead. I'm pretty sure a real SVA1032X will be cheaper than the new 3.6 GHz SHA851A. 

[m k]

Left a few bids on the junk at PP auctions, they won't let me buy a Rotek either, think "skycontrols" is controlling the prices to make sure there are no bargains (it's in the T&Cs as we found some time ago).

David

I can't say who is real.
All parties had all kind of bids and skycontrols had many one bid winners.

We know that some are real but are there any other connections, like somebody have met somebody else?

[m k]

Do you need some cable to go with it, needs quite thin stuff?

David

Before I need anything I have to check the trafo.
Original fuse was out so who knows what the reality is, and of course the thing is packed away, not far though.

If trafo is sane I'll accept the new connector, if you think you won't have the rainy day one day.
Cables are not needed, I have cables, starting from those not-really-for-manual-operations.
Maybe even mains cable of today will do, I'm sure some are under 0.75mm2 but still full of molded approvals.

The connector seems to be pretty widely used, maybe somewhere is an unknown and ready made cable stock.
Somebody had named it as a servo connector and some gas burners have also used it.

For trafo test I've thought those extra 12/240V UPS trafos I happen to have.
The set also includes some 12V relays and small current trafos, other situation has given AD capable PIC chips.
Making a pack to back isolator would give a nice middle ground for power of overcurrent circuit.
Hi-Fi version with 3+2 binary LEDs would give 25-775mA scale with 25mA steps.
Maybe the PIC chip is also fast enough for power counting and so can do a timed fuse.
Or maybe I just use one of those PCB mini fuses.

[Vince]

Geez, just back from work, checking Leboncoin.fr , what do I see ?! FRUSTRATION !! Nothing but ... FRUSTRATION !

[...}

Then, even worse....

That really nice Rochar Neeksee DMM Factory just found, that I have never seen before, guess what ? YES, one just popped here today ! You just can't make that up ! And only 10 Euros as well, not the usual 100/150 BS !! BUT !!!.... the very title of the ad says it's reserved for some guy by the name of " Rémy " already !!! 

Life sucks, we all know that. It sucks big time. It's unfair, it's unjust, it's mean, it's brutal, disgusting, useless, worthless, it's a joke we are all forced into without our explicit consent. It's a tragedy.

However, within that severely depressing reality, there are still here and there, well hidden, scarcely distributed..... tiny islands, tiny pockets, tiny bubbles... of goodness. Bubbles that no matter how rare and tiny, somehow manage to make us feel this stupid life might actually be worth living, after all.

No, I didn't mean to post this on Philosophy_Anonymous, though I am sure there must be such a forum on the interweb somewhere.

No, I sure did mean to post on TEA and nowhere else...

That Rochar DMM that popped up yesterday that said it was reserved to "Rémy"... well I am back home from work and I ran my daily search for stuff and go figure, this ad popped up again ?!

https://www.leboncoin.fr/collection/2251436987.htm

Why did it get relisted (this morning at 8H40)... hmmm.... so I had a closer look at it. I noticed that somehow the seller modified the title of the ad, it now made NO mention of being reserved for Rémy.. or anybody else for that matter !  I clicked on the ad to read the full description.... still no mention of the thing being reserved... and it even said the guy is willing to ship ?!

Better yet, guy enabled the "Buy" button, so yes, sure enough I clicked on that button ! 
... expecting the guy to reply sorry it's reserved, or already sold during the course of today.... but no, guy was online and replied to me within 10 seconds, was baffled. Said " yes it's still available but it's heavy at 10kg !! ". I said what do you care, I have already paid for shipping, just send the stupid thing and HURRY UP !!! 
Then he said "sorry but with bank holiday then the week-end, I probably won't be able to send it before Saturday or even Monday next week ! "

THAT'S FINE DUDE ! AS LONG AS I DO ACTUALLY GET THIS THING, I AM HAPPY

Yes, I can't quite believe it... I was so depressed yesterday about not being able to buy it... and just 24H later so overjoyed that the wind changed and it's now soon to be mine, for only 10 Euros (+12 Euros for shipping & fees) at that !!! 

OK it looks really dirty, like it sat in a barn for 30 years... but looking at all the pics, it looks like there is nothing fundamentally wrong with it, cosmetic-wise, it should clean up decently well, not too worried. As far as electrical condition, given the pics and what the guy says, we know it powers up, that all display tubes are bright and working, and that the  guts of the meter basically work since the guy managed to measure some voltage with it. Connected it to a 9V battery... reads 6.5V. That's fine.... who cares....it's got to be fixable.

I just can't wait to receive this thing, a fourth Rochar Neeksee piece of TE in my collection ! 

Obviously the lack of any technical information on this thing, will make it a challenge to fix.
So no doubt that there are countless hours of reverse engineering and probing around and trial and error and experimenting... ahead.
That's fine, that's how you build a strong, durable relationship with your TE ! 

Plus, since Factory has the exact same instrument, with the same plugin type as well in it... hopefully we will be able to help each other and get both our units working just fine 

What's more ? Believe it or not... today is my birthday !!!    Not even kidding ! 45 today...
So no doubt this Rochar and me were MEANT to meet... it was our destiny, it's no coincidence 
It must be a birthday present sent from outer space, from Elektronika, the goddess of all things TE 

Sorry for the length... it's just that I am so happy to have managed to make this puppy mine, needed to share the joy that's filling my little heart right now ! 

It's an anonymous therapy group after all, so it's perfectly fitting...

[m k]

There's justice in the world.