Test Equipment Anonymous (TEA) group therapy thread

[bd139]

I'm going to put an offer in of £1 lol.

[Specmaster]

A comedy bid for comedy pricing 

[PA4TIM]

Everybody knows what the problem is if you have only 2 calibrators. But what if you have 4 warmed up and ready to check the calibrator you just repaired and all gave a different reading on all your multimeters ? And very scary, the differences where round numbers. The repaired one was +200 uV of, my Datron 4700, -100 uV (if I use the Fluke 332 here as a reference.) And my TC303 +100 uV. But It gets worse. My Keithley 2000 as a reference (see under here) . A TTI 1906 was +200 uV , my Keithley 196 was the same as the 2000 (this is always the case), My Prema 5017 made things worse, it was almost 300 uV low in 3V range but +100 uV in 30V range. My Solartron 7061 was close to the Keithleys at 1 V but I do not trust  it until it is powered on a few days. But my Brymen 869S and my TTi was spot on on the Datron (that is at 1V)

But at this point I was confused and started to doubt about everything.
 
Then I went back to the basics. Set my 332 at 10V and equal to a standard cell,  (845 nulmeter, ESI KV divider (and a Fluke 720 to check)
Then coupled it to my best and most stable DMM (Keithley 2000 bought new a few years ago). And used it in the 1V range to measure the cell direct.
 And then I switched  the KV divider through all positions from 10 uV to 10V. The cell I used is 1.018,146 V The keithley showed 1.018,149 and as lineair as a virgin but aged DMM.  Playing with KV's is very addicting. The solartron was also very lineair. The TTi's not and I had calibrated them with the Datron so I did the same thing with the Datron.
Turns out my Datron needs a good alignment. It is stable but to much off and far from lineair. And my Prema has a serious problem because it always gave the same readings (max -11uV) difference as the 2000. and also not lineair. To bad I do not have the SM.

But this was a very difficult situation, the first thing that comes to mind is, I need a 8,5 digit multimeter but I was strong. 

[beanflying]

I am with you a calibrated 8.5 digit is needed 

5 or 6 References, couple of standard cells and a dozen plus accurate methods to measure them 'so far' 

And then I started playing with my first couple of GPSDO's 

[mnementh]

A "thank you" gift I received from a member here for helping them out.  I wasn't expecting anything in return, I just enjoyed helping them.  I felt a bit self-conscious and it took me a couple of days to accept, but it was a very kind gesture and one that I have already made use of.

Oh, that's the GOOD one... which they have for some reason mysteriously discontinued.

Now that's what I call some good Karma.

Comedy pricing:

https://www.ebay.co.uk/itm/362266671092 

Spot the problem with it.

Holly crap, are those bullet holes on the side ?!?!? 

It has clearly been cannibalized for parts to fix another one; the current bridge PCB (attached to one of the missing knobs) is a high failure item due to user error. Looks to me like the base voltage divider board has also been robbed. It is not uncommon for these to be sold without the DUT jigs, however it appears the sockets under the front panel are also missing (another PCB probably robbed).

The sides on these are held on with DZUS fasteners. It is not uncommon for them to be covered with Lease/warranty/calibration seals; that looks like seal/sticker residue to me.

Everybody knows what the problem is if you have only 2 calibrators. But what if you have 4 warmed up and ready to check the calibrator you just repaired and all gave a different reading on all your multimeters ? And very scary, the differences where round numbers. The repaired one was +200 uV of, my Datron 4700, -100 uV (if I use the Fluke 332 here as a reference.) And my TC303 +100 uV. But It gets worse. My Keithley 2000 as a reference (see under here) . A TTI 1906 was +200 uV , my Keithley 196 was the same as the 2000 (this is always the case), My Prema 5017 made things worse, it was almost 300 uV low in 3V range but +100 uV in 30V range. My Solartron 7061 was close to the Keithleys at 1 V but I do not trust  it until it is powered on a few days. But my Brymen 869S and my TTi was spot on on the Datron (that is at 1V)

But at this point I was confused and started to doubt about everything.
 
Then I went back to the basics. Set my 332 at 10V and equal to a standard cell,  (845 nulmeter, ESI KV divider (and a Fluke 720 to check)
Then coupled it to my best and most stable DMM (Keithley 2000 bought new a few years ago). And used it in the 1V range to measure the cell direct.
 And then I switched  the KV divider through all positions from 10 uV to 10V. The cell I used is 1.018,146 V The keithley showed 1.018,149 and as lineair as a virgin but aged DMM.  Playing with KV's is very addicting. The solartron was also very lineair. The TTi's not and I had calibrated them with the Datron so I did the same thing with the Datron.
Turns out my Datron needs a good alignment. It is stable but to much off and far from lineair. And my Prema has a serious problem because it always gave the same readings (max -11uV) difference as the 2000. and also not lineair. To bad I do not have the SM.

But this was a very difficult situation, the first thing that comes to mind is, I need a 8,5 digit multimeter but I was strong. 

Confucius say: Man with a watch always knows what time it is; man with two is never sure.




In other news: My new bed came today. Now I need to assemble it so I can go to sleep.


mnem
I think I wanna go take a nap first; it's been a long day.

[bitseeker]

A "thank you" gift I received from a member here for helping them out.  I wasn't expecting anything in return, I just enjoyed helping them.  I felt a bit self-conscious and it took me a couple of days to accept, but it was a very kind gesture and one that I have already made use of.

Oh, that's the GOOD one... which they have for some reason mysteriously discontinued.

Ah, I saw you inquired about that mystery here in January as well. According to kj7e, "Doug cited costs at one point.  Just not very profitable in the end."

I'm undecided about getting one.

If you want one, Doug is making some batches of them. Orders are closed right now as the current batch is burning in and then shipped out. The next batch is slated to be open for orders beginning on or about April 1 (hopefully, not kidding).

[mnementh]

Oh yeah... I was very disappointed when I went to the site and they weren't available; hopefully once I pay my taxes there'll be a little left over.

At ~$100 for everything it does, that little board is a marvel. I can see how it would be a bit hard to make a profit though; most garden variety users who just wanna make sure their meter works right are gonna say to themselves "That $100 is better put towards a new Fluke"; even for me it's as much a matter of money and timing.


mnem
*Toddles off to ded*

[bitseeker]

I certainly hope you're not heading to "ded."

Yeah, it's a good feature set for a Benjamin. The reason I'm undecided is that my main DMMs are 6.5 digits.

[tautech]

I certainly hope you're not heading to "ded."

You not seen that from mnem before ?
It's his standard close of day sig. 

[bitseeker]

So much to read, so little time.

[bd139]

Confucius say: Man with a watch always knows what time it is; man with two is never sure.

This is TEA. Confucius go buy GPSDO and transfer standard

[tautech]

Confucius say: Man with a watch always knows what time it is; man with two is never sure.

This is TEA. Confucius go buy GPSDO and transfer standard

 

[PA4TIM]

I'm a bit confused now...isn't a confuser a cheap Chinese multimeter without a fuse ? 

I bought a multimeter from the states, when I tried it the reading did not make sense.  Turned out it used imperial Volts, that was really confusing.

[Specmaster]

I'm a bit confused now...isn't a confuser a cheap Chinese multimeter without a fuse ? 

I bought a multimeter from the states, when I tried it the reading did not make sense.  Turned out it used imperial Volts, that was really confusing.

🤣🤣🤣

[bd139]

Actually that reminds me. My father bought a no brand DMM in I think 83 from a shop in Tottenham Court Road and took it to bits. The fuse in it actually had a trace between both terminals on the PCB. Clearly the cheaper end of the market wasn’t going to be blessed with a fuse and the higher end wasn’t going to be blessed with competence. 

[Specmaster]

Actually that reminds me. My father bought a no brand DMM in I think 83 from a shop in Tottenham Court Road and took it to bits. The fuse in it actually had a trace between both terminals on the PCB. Clearly the cheaper end of the market wasn’t going to be blessed with a fuse and the higher end wasn’t going to be blessed with competence. 

The trace was possibly the fuseable element, designed to be used as a fuse and in the event of it being blown, the user had buy a fuse to restore the circuit again?

[bd139]

I think if the fuse was installed they were supposed to cut the trace. It was exposed through the solder mask.

I remember having to go back the next weekend with him and listen to him arguing with the shop keeper about it.

[Specmaster]

I think if the fuse was installed they were supposed to cut the trace. It was exposed through the solder mask.

Oh, I have seen the use of a sacrificial trace before though, they are made very thin for that purpose so any attempt at current carrying it cuts it's own throat.

[Brumby]

The trace was possibly the fuseable element, designed to be used as a fuse and in the event of it being blown, the user had buy a fuse to restore the circuit again?

I can see the train of thought to lower the BOM:  Put in the fuse holder (because it will likely be needed) but save on the cost of a fuse and installing it.

[bd139]

I think if the fuse was installed they were supposed to cut the trace. It was exposed through the solder mask.

Oh, I have seen the use of a sacrificial trace before though, they are made very thin for that purpose so any attempt at current carrying it cuts it's own throat.

Hewlett Packard are good at designing them in by accident 

The trace was possibly the fuseable element, designed to be used as a fuse and in the event of it being blown, the user had buy a fuse to restore the circuit again?

I can see the train of thought to lower the BOM:  Put in the fuse holder (because it will likely be needed) but save on the cost of a fuse and installing it.

Yep sounds about right. Probably typical HK/Taiwan business practice at the time:

1. Go to HK and talk to exporters about their products. Get shown a nice example with all the bells and whistles.
2. Order 5000 of them.
3. When container arrives, inspect one and find there is no fuse holder.
4. Whine about it to the exporter.
5. Big discount on next batch which will have fuses.
6. Buy another 5000.
7. Turn up and see the fuse holder and not think further into it.

(my father was also an importer of clone PC crap for many years so our house was full of boxes of failures).

[Specmaster]

I had thought due to the tracking info on AliExpress that I might actually have got my new T12 controller this week. Further investigation of it shows that when it said early in the week that it had left country of origin, it was lieing to me. It meant it had left central China for  a 650 mile flight to Beijing, were its been sitting for the last 4 days.

I really believe that they need to overhaul their postal system to bring it into line with the rest of the world.

From mobile device so predictive text might have struck again [emoji83]

[bd139]

Having same problem with some shit from aliexpress. I think it's backlog due to the new year stuff.

Actually had a few things returned to the sender apparently. I just claim them straight up. Not worth arguing. Got someone begging for good feedback because I just claimed it and has sent it again anyway.

[Specmaster]

I think if the fuse was installed they were supposed to cut the trace. It was exposed through the solder mask.

Oh, I have seen the use of a sacrificial trace before though, they are made very thin for that purpose so any attempt at current carrying it cuts it's own throat.

Hewlett Packard are good at designing them in by accident 

The trace was possibly the fuseable element, designed to be used as a fuse and in the event of it being blown, the user had buy a fuse to restore the circuit again?

I can see the train of thought to lower the BOM:  Put in the fuse holder (because it will likely be needed) but save on the cost of a fuse and installing it.

Yep sounds about right. Probably typical HK/Taiwan business practice at the time:

1. Go to HK and talk to exporters about their products. Get shown a nice example with all the bells and whistles.
2. Order 5000 of them.
3. When container arrives, inspect one and find there is no fuse holder.
4. Whine about it to the exporter.
5. Big discount on next batch which will have fuses.
6. Buy another 5000.
7. Turn up and see the fuse holder and not think further into it.

(my father was also an importer of clone PC crap for many years so our house was full of boxes of failures).

Yep, bullshit baffles brains everytime.

From mobile device so predictive text might have struck again [emoji83]

[Specmaster]

Having same problem with some shit from aliexpress. I think it's backlog due to the new year stuff.

Actually had a few things returned to the sender apparently. I just claim them straight up. Not worth arguing. Got someone begging for good feedback because I just claimed it and has sent it again anyway.

Waiting on the 3rd T-Conn board to arrive, 1st one was cancelled by seller, 2nd from a new seller never had tracking updated. Complained and so 3rd was dispatched, tracking was showing waiting collection for ages, now it is in the hands of the airline. So far 3rd one has been 3 weeks almost and does not appear to have left China!

From mobile device so predictive text might have struck again [emoji83]

[bd139]

sounds like wun hung lo is wun lazy bastard this month

Edit: just asked for another refund because "shipment cancelled by seller". Ffs. I'm sure some people are running this as a hedge fund on micropayment currency trades rather than a shipping service.

Edit 2: Might be onto something. Bought something for 5.21. Got refund for 5.67.