Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

Karma is good to me after that rant. I just bought a 3478A to match the 5384A 

deja vu again? be careful of the battery backed ram.

[bd139]

Yeah not going to bugger this one up 

All kit is buy to keep now 

[Saskia]

Just a quick question
Was Charles Goodyear the very first Tyrecoon ever?

Asking for a friend.


 

He had constructed the USS Tyreconderoga, the first Landcruiser.

[BU508A]

Karma is good to me after that rant. I just bought a 3478A to match the 5384A 

 

 

 

[mnementh]

Karma is good to me after that rant. I just bought a 3478A to match the 5384A 

Ahhhh... life is good. 

mnem
 

[Cubdriver]

To acknowledge page 3430 (!!! holy shit!!)  of the TEA thread:



-Pat

[mnementh]

Mini rant: Kubernetes is Pandora’s box incarnate. No one knows entirely how it works. No one knows entirely what it does. But the outcome is nearly always mayhem and chaos. Much like “The Cube”, it is written by lots of people who independently concentrate on their little bits of the machine unaware of each other and the sum of the parts resulting in the destructive potential for the cumulative pile of mistakes in each part. From synchronising state across several partitions, through Rube Goldberg chains of events, struggling through eventual inconsistency and landing on mutant vocabulary they have succeeded only in removing understanding and determinism from computing. When all hell breaks loose you cannot reason about fixing it because of the inane complexity because you can’t communicate the problem nor rationalise it due to the non determinism.

At this point I am going to sit back, buy test gear to play with and watch it all fucking burn and hope I get paid to pretend I give a shit.

If this is entire thing means nothing to you then you are lucky bastards.

And med, nice score. Even if it cost you a tyre

For a moment there I thought you were talking aboot Windoze and AD; then I noticed that not once did you curse PowerShell...

mnem

[bd139]

Don’t get me started on PowerShit 

[Specmaster]

Incidently just rewatched Dave's video on the 3478A and from 10:30 on he talks about the battery backed RAM and if you disconnect the battery or short it out you will lose the calibration constants  and will then need to spend more money then you paid for the meter to get it traceable calibrated once again. So in his view, having a meter calibrated does indeed involve having adjustments made to the meter to return it to the design specifications again and not just verifying and noting any drift that the user should take into account when using said meter. So Dave and I both share the view that calibration is not a case of checking against references and recording the differences, but actually includes making the necessary adjustments to make the meter reflect the references applied to it.   

[mansaxel]

Yeah not going to bugger this one up 

All kit is buy to keep now 

I give this three months, tops. Before "flipped it".

[Saskia]

Mini rant: Kubernetes is Pandora’s box incarnate. No one knows entirely how it works. No one knows entirely what it does. But the outcome is nearly always mayhem and chaos. Much like “The Cube”, it is written by lots of people who independently concentrate on their little bits of the machine unaware of each other and the sum of the parts resulting in the destructive potential for the cumulative pile of mistakes in each part. From synchronising state across several partitions, through Rube Goldberg chains of events, struggling through eventual inconsistency and landing on mutant vocabulary they have succeeded only in removing understanding and determinism from computing. When all hell breaks loose you cannot reason about fixing it because of the inane complexity because you can’t communicate the problem nor rationalise it due to the non determinism.

At this point I am going to sit back, buy test gear to play with and watch it all fucking burn and hope I get paid to pretend I give a shit.

If this is entire thing means nothing to you then you are lucky bastards.

And med, nice score. Even if it cost you a tyre

For a moment there I thought you were talking aboot Windoze and AD; then I noticed that not once did you curse PowerShell...

mnem

gimme gimme gimme !!!

[Specmaster]

Yeah not going to bugger this one up 

All kit is buy to keep now 

I give this three months, tops. Before "flipped it".

I was kinda thinking the same.

[bd139]

Incidently just rewatched Dave's video on the 3478A and from 10:30 on he talks about the battery backed RAM and if you disconnect the battery or short it out you will lose the calibration constants  and will then need to spend more money then you paid for the meter to get it traceable calibrated once again. So in his view, having a meter calibrated does indeed involve having adjustments made to the meter to return it to the design specifications again and not just verifying and noting any drift that the user should take into account when using said meter. So Dave and I both share the view that calibration is not a case of checking against references and recording the differences, but actually includes making the necessary adjustments to make the meter reflect the references applied to it.   

Dave’s wrong then. The formal definitions are:

Calibration - documentation of a comparison to a standard or calibrator.

Adjustment - adjustment of the device to match a standard within the device specifications.

Watch what happens if you send a device to a decent cal lab and ask for a calibration only. You’ll get a bit of paper back with “FAIL” on anything wrong and a quote for an adjustment stapled to the back

[bd139]

Yeah not going to bugger this one up 

All kit is buy to keep now 

I give this three months, tops. Before "flipped it".

I was kinda thinking the same.

I’m only flipping it if it’s a turd 

[Mr. Scram]

I give this three months, tops. Before "flipped it".

Agreed. Unlike bd, I'm not buying it. But it's a free country and if a man wants to tell himself stories, why not?

[Robert763]

Been a bad week at work. Trying not to loose my cool with "engineers" with advanced degrees who can't work out the current and power in 3 resistors connected across a 3 phase supply in star or delta  They did spend 1/2 day building a nice computer model. It included the the temperature derating graph from the datasheet so as the heatsink temperature went up the power went down I managed not to ask them how they were going to acheive that in the circuit. What's really worrying is that they are not stupid, the education system is letting them down.

As a result I spent some money on mystery TE www.ebay.co.uk/itm/Aircraft-Parts-Ground-Equipment-GROUND-AAIR-TRAINING-WEAPONS-EFFECT-SIM-TEST-SET/384017553215?

And one of these (I have one already)
https://www.ebay.co.uk/itm/BCF-Designs-S2471-MIL-STD-1553-Databus-Harness-Tester-ULTRA-ELECTRONICS/223478529664?
Oh not that one, this one
https://www.ebay.com/itm/373493302263?nordt=true&orig_cvip=true&rt=nc&_trksid=p2546137.m43663.l10137

A LOT cheaper  It's basically a 1Mb/s transmission loss tester for 78R balanced screened network cables. It a current model and a new one from Ultra Electronis will cost about £20,000  well worth 99p 
https://www.ultra-pcs.com/air/ground-test-equipment/databus-network-analyser/

[Cerebus]

Experimenting with using FreeNAS for a new file server at home:



That's millions of bytes per second, not bits per second - I saw it hit upwards of 750 MiB/s. Just chucked 100 Gb of videos onto it in about 5-6 minutes. Sustained write speed of ~ 277MB/s on spinning rust in a machine that cost less than £400 all in (Second hand ProLiant ML310e Gen8 v2, another 16Gb of memory to take it to 32Gb and 4 off 2Tb spinning rust).

[bd139]

That's pretty impressive 

[THDplusN_bad]

To acknowledge page 3430 (!!! holy shit!!)  of the TEA thread:



-Pat

yippee yippee yay, Pat!

Keep those Nixies glowing. Fantastic. I have found out that 3 digits are very often absolutely sufficient for repair work.
BTW, here is an interesting read about these early digital voltmeters from HP: https://www.hpmemoryproject.org/wb_pages/wall_b_page_14b.htm

Cheers,

THDplusN_bad

[bd139]

Yes that is one sexy DMM that is  . Need more photos like that

Just ordered some OSC5A2B02 OCXO modules to play with... it has begun.

[factory]

Much prefer the DVM myself. 



David

[Specmaster]

Incidently just rewatched Dave's video on the 3478A and from 10:30 on he talks about the battery backed RAM and if you disconnect the battery or short it out you will lose the calibration constants  and will then need to spend more money then you paid for the meter to get it traceable calibrated once again. So in his view, having a meter calibrated does indeed involve having adjustments made to the meter to return it to the design specifications again and not just verifying and noting any drift that the user should take into account when using said meter. So Dave and I both share the view that calibration is not a case of checking against references and recording the differences, but actually includes making the necessary adjustments to make the meter reflect the references applied to it.   

Dave’s wrong then. The formal definitions are:

Calibration - documentation of a comparison to a standard or calibrator.

Adjustment - adjustment of the device to match a standard within the device specifications.

Watch what happens if you send a device to a decent cal lab and ask for a calibration only. You’ll get a bit of paper back with “FAIL” on anything wrong and a quote for an adjustment stapled to the back

Well, while not wanting to stir up a hornets nest again about calibration services, but you will remember that when I lost my data on my 3478A due to the piece of solder I was using, touched the chassis while soldering in the new battery. I contacted RS about having a calibration carried out to restore it, they gave me a price for the job, and it was dispatched. After many emails back and forth after they failed to return it to me as promised within so many days, they said that they were having trouble in getting it to retain any corrections they made to it and eventually returned it to me and refunded the fee? Also, as you will remember I managed by reading the manual, to calibrate myself in the end without any problems and used it for well over a year before parted company with it.

Plus of course the unit itself has a switch on the front panel that has to be engaged in order to carry out a calibration, called "Cal Enable"? If it was just simply checking it against known standards then there is no need for that switch at all.

I also contacted many calibration labs and all of them said they were unable to carry out the calibration on that particular meter, before RS said that they could do it? If calibration is just testing against known values and the results being recorded and the data sheet returned along with the meter so the user is aware of the inaccuracies of the meter, why could they not do that? That is really what all the manufacturers call either a performance check, or a calibration check in their service manuals and this is done with the meter in normal mode by feeding it with known values and recording the indicated results for each known value. In order to adjust the readings, you have to enable the "calibration mode" of the meter which most bench meters have a switch and indicator on their front panels, or rear panels and the service manuals also refer to this as "calibration" and once again the same known values as used and defined in the check mode, are fed to the device and then the displayed results can be adjusted  and adjustments saved to either volatile RAM or EPROM which ever the meter is equipped with. This to me and the manufacturers is "calibration" anything else is purely checking or performance testing and no adjustment is possible in that mode.

I can't help but think that if you send a meter for calibration and they do as you said, send it back with FAIL against parts that were not correct and a quote to rectify it, that to my mind is totally wrong. If you had requested a calibration check only, then I'd agree with the quote for repairs/adjustment because it would mean that the lab and engineers having to handle the meter twice. But if you had sent them the meter and asked for a "calibration" then that should be the check and adjustment, as the check has to be done in order to see if adjustment is required. In that case if they returned the meter and it FAILed against certain ranges and a quote, then that to me would indicate that the meter requires parts to be replaced because the corrective adjustments could not bring that range back to tolerances.

[factory]

The latest arrivals, the first is a Biddle branded AVO DA114 that has been repatriated from the US, together with the one on the left which apparently came from the Birmingham MSI, well that's what the sticker on the bottom says, probably used by the maintenance team rather than an exhibit. All history now as the MSI closed in 1997 and has been mostly erased from history by bulldozers.
The Biddle AVO needs a bit of adjustment, the test source is an old RAM battery removed from a Tek scope, the AVO on the left is reading correct. 


And the other arrival from Germany, a HP 5216A which was advertised as defective, after temporarily fitting a Macroni knob & switching it away from the "stop" function it might be OK after all  , needs a bit more testing to check all digits tomorrow.


David

[Specmaster]

Been a bad week at work. Trying not to loose my cool with "engineers" with advanced degrees who can't work out the current and power in 3 resistors connected across a 3 phase supply in star or delta  They did spend 1/2 day building a nice computer model. It included the the temperature derating graph from the datasheet so as the heatsink temperature went up the power went down I managed not to ask them how they were going to acheive that in the circuit. What's really worrying is that they are not stupid, the education system is letting them down.

As a result I spent some money on mystery TE www.ebay.co.uk/itm/Aircraft-Parts-Ground-Equipment-GROUND-AAIR-TRAINING-WEAPONS-EFFECT-SIM-TEST-SET/384017553215?

And one of these (I have one already)
https://www.ebay.co.uk/itm/BCF-Designs-S2471-MIL-STD-1553-Databus-Harness-Tester-ULTRA-ELECTRONICS/223478529664?
Oh not that one, this one
https://www.ebay.com/itm/373493302263?nordt=true&orig_cvip=true&rt=nc&_trksid=p2546137.m43663.l10137

A LOT cheaper  It's basically a 1Mb/s transmission loss tester for 78R balanced screened network cables. It a current model and a new one from Ultra Electronis will cost about £20,000  well worth 99p 
https://www.ultra-pcs.com/air/ground-test-equipment/databus-network-analyser/

By the use of the word degrees, I take it that these engineers went to uni rather than a technical college and if that assumption is correct, you have successfully illustrated a point I made sometime ago about the differences between such training places and the end results. I used the example of an ex uni consultant with excellent degrees insisting that an electrical contractor feed a normal twin switched 13A socket out from 2 phases on a large prestige block of luxury flats in Woolwich. It was bad enough to be introducing 2 phases in a domestic dwelling but having them connected together like that  . He could have used 2 single sockets on a dual box but even then it would have required phase barriers and approbate signage, and we all know how the occupant would react to that signage don't we?

[bd139]

Incidently just rewatched Dave's video on the 3478A and from 10:30 on he talks about the battery backed RAM and if you disconnect the battery or short it out you will lose the calibration constants  and will then need to spend more money then you paid for the meter to get it traceable calibrated once again. So in his view, having a meter calibrated does indeed involve having adjustments made to the meter to return it to the design specifications again and not just verifying and noting any drift that the user should take into account when using said meter. So Dave and I both share the view that calibration is not a case of checking against references and recording the differences, but actually includes making the necessary adjustments to make the meter reflect the references applied to it.   

Dave’s wrong then. The formal definitions are:

Calibration - documentation of a comparison to a standard or calibrator.

Adjustment - adjustment of the device to match a standard within the device specifications.

Watch what happens if you send a device to a decent cal lab and ask for a calibration only. You’ll get a bit of paper back with “FAIL” on anything wrong and a quote for an adjustment stapled to the back

Well, while not wanting to stir up a hornets nest again about calibration services, but you will remember that when I lost my data on my 3478A due to the piece of solder I was using, touched the chassis while soldering in the new battery. I contacted RS about having a calibration carried out to restore it, they gave me a price for the job, and it was dispatched. After many emails back and forth after they failed to return it to as promised within so many days, they said that they were having trouble in getting it to retain any corrections they made to it and eventually returned it to me and refunded the fee? Also, as you will remember I managed by reading the manual, to calibrate myself in the end without any problems and used it for well over a year before parted company with it.

Plus of course the unit itself has a switch on the front panel that has to be engaged in to carry out a calibration, called "Cal Enable"? If it was just simply checking it against known standards then there is no need for that switch at all.

I also contacted many calibration labs and all of them said they were unable to carry out the calibration on that particular meter, before RS said that they could do it? If calibration is just testing against known values and the results being recorded and the data sheet returned along with the meter so the user is aware of the inaccuracies of the meter, then that is really what all the manufacturers call either a performance check, or a calibration check in their service manuals and this is done with the meter in normal mode by feeding it with known values and recording the indicated results for each known value. In order to adjust the readings, you have to enable the "calibration mode" of the meter which most bench meters have a switch and indicator on their front panels, or rear panels and the service manuals also refer to this calibration and once again the same known values as used and defined in the check mode, are fed to the device and then the displayed results can be adjusted  and adjustments saved to either volatile RAM or EPROM which ever the meter is equipped with. This to me and the manufacturers is "calibration" anything else is purely checking or performance testing and no adjustment is possible in that mode.

I can't help but think that if you send a meter for calibration and they do as you said, send it back with FAIL against parts that were not correct and a quote to rectify it, that to my mind is totally wrong. If you had requested a calibration check only, then I'd agree with the quote for repairs/adjustment because it would mean that the lab and engineers having to handle the meter twice. But if you had sent them the meter and asked for a "calibration" then that should be the check and adjustment, as the check has to be done in order to see if adjustment is required. In that case if they returned the meter and it FAILed against certain ranges and a quote, then that to me would indicate that the meter requires parts to be replaced because the corrective adjustments could not bring that range back to tolerances.

It’s never quite that simple. There is an important scenario you need to consider which is invalidation of measurements. If you find your calibration fails then the certainty of measurements that have been made since the previous calibration should be called into question. At that point the device is usually returned to the client until their investigation is complete. If the instrument is found to have violated the worst case specification drift then it’s usually sent back to the manufacturer for repair of in warranty or scrapped if not. If it’s expected then it may be shelved as “for indication only” and used for casual work that doesn’t require traceable measurements, or send for adjustment.  Or in the case of where I worked chucked in a pile of suspect stuff and thrown in a skip about 2 years later because it was cheaper to replace it than play crap tennis.

Regarding the calibration process, this is mostly automated. The reason the cal houses turned down the 3478A is probably because they don’t have any programs for their kit. The RS guys probably downloaded a PDF from somewhere random, poked at it like some monkeys around a monolith and gave up.

Edit: apparently this has been standardised under one of the ISO QMS standards which I can’t be arsed to dig through now as I’m all full of 27001 at the moment