Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

   Only YOU (me? me!) can prevent socialist ranting by posting actual TE content!

Aww, come on man... it weren't that much of a rant. And I'm not much of a socialist, either. I'm a humanist.

The problem with EVs is...yeah, there's all kinds of horrible in them as they're made and sold right now. But the way people drive the market is with their dollars... so if we really want the infrastructure to happen that makes EV possible, and we really want to change how electricity for that infrastructure is generated, first we have to make it clear to these smoke-filled-boardroom-dwelling morlocks that we aren't going to accept anything less than a future based on EV, where ICE are used very infrequently, primarily as boostrap energy to get real clean energy happening.

And we do that by voting with our dollars. Once EVs are the new normal, then we can start pressuring them to make the cars with better manufacturing carbon footprints and the electricity generation carbon neutral.

Remember... the people driving dirty energy are the worst of humanity. We have to be 1000x better than they are to make things right.

mnem
Also, we might get some fresh O₂ as a side incentive...

[med6753]

The Tek 485 in 50 ohm input impedance mode is an excellent scope. Flat response in all attenuator settings and frequencies. The 485 in 1MEG input impedance mode is an exercise in frustration to get the compensation looking decent at all attenuator settings. Channel 1 was OK but Channel 2 needed adjustment. If you try to follow the manual you'll be scratching your head and wonder if the engineer that wrote the instructions was drunk. And to add to fun there's stuff clearly left out. After going back and forth several times and getting practically no where I ditched the manual. Using my experience in compensating other vertical pre-amps I applied what I thought made sense. Now I'm no wonder boy but the compensation fell right into place as it should. I don't know why the manual is so needlessly complex and this isn't the first time I've run into issues with the 485 manual. Overall I think it's poorly written.

I need to tweak the Channel 1 1MEG compensation on my other 485 and I'll tackle that tomorrow.

   

[Robert763]

The Sunset E10 tester arrived today. Seems to work, but the basic datacom cable that all those leads and adaptors connect to is missing    It appears to be unobtainable too, Has a HDI-30 plug on it (was used on some MAC SCSI interfaces). So looks like the E10 won't be much use other than testing coax at 2.048 MHz.

Anyone got an old MAC SCSI lead with a HDI-30 (30 pin square) plug? Maybe I could hack one of those into something usable.

Please send detailed image of connector. I have recently seen a gaggle of related types in a drawer.
Could check next week.

Thanks for offering to look. 30 pins on 5x6 grid

[Neomys Sapiens]

   Only YOU (me? me!) can prevent socialist ranting by posting actual TE content!

Aww, come on man... it weren't that much of a rant.

No, but it provided me with a nice opening line. 

And I'm not much of a socialist, either. I'm a humanist.

Dare I guess which is rated worse by the people above&behind me?

O₂? Dont you want finally to make the upgrade to O₃?

[tggzzz]

The Tek 485 in 50 ohm input impedance mode is an excellent scope. Flat response in all attenuator settings and frequencies.

It is a delightful scope, and will be last one I sell. "Pry it out of my dead hands" territory.

The 50ohm input is lovely because it is 50ohms, not 50ohms // 20pF.

[factory]

   Only YOU (me? me!) can prevent socialist ranting by posting actual TE content!

Aww, come on man... it weren't that much of a rant. And I'm not much of a socialist, either. I'm a humanist.

The problem with EVs is...yeah, there's all kinds of horrible in them as they're made and sold right now. But the way people drive the market is with their dollars... so if we really want the infrastructure to happen that makes EV possible, and we really want to change how electricity for that infrastructure is generated, first we have to make it clear to these smoke-filled-boardroom-dwelling morlocks that we aren't going to accept anything less than a future based on EV, where ICE are used very infrequently, primarily as boostrap energy to get real clean energy happening.

And we do that by voting with our dollars. Once EVs are the new normal, then we can start pressuring them to make the cars with better manufacturing carbon footprints and the electricity generation carbon neutral.

Remember... the people driving dirty energy are the worst of humanity. We have to be 1000x better than they are to make things right.

mnem
Also, we might get some fresh O₂ as a side incentive...

This might still apply in some places.


We still have diesel powered trains moving shit-tonnes of coal, shaking the house every few days , not sure exactly where it goes after the sidings. Most coal power generation in the UK has gone bar a couple of stations.
https://www.realtimetrains.co.uk/service/gb-nr:H20927/2022-02-07/detailed


At least that is mined in the UK, we used to have imported coal going through, to Fiddler's Ferry power station until it closed a couple of years ago.
https://www.bbc.co.uk/news/uk-england-merseyside-52100822

David

[Cerebus]

There is MRI safe janitorial equipment.   It is expensive --  ~$1000 for a mop and bucket.    -> http://ketteringsurgical.co.uk/shop/mri/mri-maintenance/dual-bucket-and-mop-system-12808.htm
Broom and dustpan is about £300 --> http://ketteringsurgical.co.uk/shop/mri/mri-maintenance/fiberglass-broom-handle-and-broom-heads-23704.htm

You've gotta laugh at the crazy markup on "special" stuff for technical purposes that could be substituted with "ordinary" cheap stuff. You can get tight arsed purchasing managers to shell out for this sort of stuff when you have a hard time getting an extra penny a roll out of them for toilet paper that doesn't shred your arse. Before computers used to be commonplace and people realised that they weren't magic fragile things I remember the shysters that used to sell very ordinary cleaning products in special "computer" versions for 20x the normal prices.

Instead of handing $$$ to Kettering you could get this, and it has the advantage that Matron could fly home on it as well. 

[Cerebus]

CONTACT CLEANER

So do you have any experience / recommendation for some cleaner from a well know brand, that I could get from Farnell ?

I use Würth Contact Spray to clean the door into the MRI faraday cage.   This was recommended by the manufacturer.   


.....snip

I'm curious. Can a person who has perhaps a metal plate in their head or metal hardware to repair a broken arm/leg get an MRI? My gut says no.

So you have ferromagnetic metal in your gut? 

Only when he's spitting nails.

[factory]

HP 6235A Fun Fact

While the supply is rated +6V  and +/- 18V maximum,  it can go quite a bit higher with no risk of damage.



Mine will regulate well past 7V and can take the meter off scale high, even under load.

7V out is fantastic.  I can use it to drive things that have an on-board 5V regulator and reverse polarity protection diode.    7805 w/series diode here:
(Sorry about the return of the AN-888S.  I needed two meters)

Looks like it was a good buy then, I thought about bidding on it but already have a hp 6237B here, it's a little bit larger though. Does the 6235A have any RIFA madness inside? the 6237B certainly did & the previous owner/user got to enjoy it .
Will probably be using it at the weekend to test the 5216A, in place of the very defective transformer, will bypass the PSU board too.



David

[Andrew_Debbie]

This might still apply in some places.

Coal power is almost gone in the UK.   



https://www.gov.uk/government/publications/fuel-mix-disclosure-data-table/fuel-mix-disclosure-data-table

[tggzzz]

There is MRI safe janitorial equipment.   It is expensive --  ~$1000 for a mop and bucket.    -> http://ketteringsurgical.co.uk/shop/mri/mri-maintenance/dual-bucket-and-mop-system-12808.htm
Broom and dustpan is about £300 --> http://ketteringsurgical.co.uk/shop/mri/mri-maintenance/fiberglass-broom-handle-and-broom-heads-23704.htm

You've gotta laugh at the crazy markup on "special" stuff for technical purposes that could be substituted with "ordinary" cheap stuff. You can get tight arsed purchasing managers to shell out for this sort of stuff when you have a hard time getting an extra penny a roll out of them for toilet paper that doesn't shred your arse.

Yes, but...

The key bit of the first sentence is "could be substituted". Some could not. The question then comes down to who (and/or which organisation) makes the dstermination and is responsible if things go tits up.

Sometimes FUD is fully justified.

[Andrew_Debbie]

Does the 6235A have any RIFA madness inside? the 6237B certainly did & the previous owner/user got to enjoy it .

There aren't any X or Y caps on the schematic.   Why would they in 1978?  The supply is entirely linear.    The schematic in the scanned manual on the Agilent website is terrible.  I can hardly read it. 

I'm going to open it up now since they don't always match the manual.

[factory]

The 6237B here is a 1977 design rev and also linear.
Often the older stuff such as the 5216A have Sprague ceramic caps across the mains inlet.


With old HP stuff it's always a good idea to check for RIFA madness & Schaffner mains inlet filters, waiting to release that special scent. 
 
David

[Vince]

I've been told by a Kontakt Chemie rep to use their stuff in this order: First clean/deox using K60, then wash away with KWL and for delicate contacts use K61 for protecting/lubricating the contacts. I've always got a big can of KWL handy, it's a good alround cleaner for electronics. Do not use on optics!

I have to say I prefer the Caig stuff, especially the D5 in the needle dripper bottle. So much less mess. I've had that small bottle for >5 years now and it is maybe 1/5 empty. Not cheap and not readily available but lasts a long time. The FaderLube is also nice for all kinds of pots.

I can second that advice on "Kontakt Chemie" products. They are a subsidiary of CRC for some time now http://www.kontaktchemie.com/KOC/.
For "simple" switches such as used in car electric or power switches, you may also want to look into https://brunox.swiss/index.php/en/products/turbo-spray
Mind the NSF certification... It's also very useful in the workshop. Turbo Spray and Ballistol in my workshop - never ever tempted to use any WD-40 again! 

Cheers,

THDplusN_okish

Poor Vince is going to need an Excel sheet to weigh all the Pros and Cons to find the "right" contact cleaner now 

No Excel sheet, but I did compile/copy/paste all of your replies in a little text file 

 @McBryce : thanks for the link at 20 Euros, much more reasonable  Need to ad 6 euros for shipping though, so ends up at 26 Euros. That said, looking at the other cleaners... most are pretty much just as expensive. As for Amazon, of course I checked, and there is ZERO ad for Deoxit D5 on the French Amazon ! Ze-ro, nada, not a sausage...   
I assume you looked on German Amazon. guess the German seller didn't want to be listed on French Amazon, maybe he doesn't want to ship there or whatever 

Anyway, thanks everybody for your replies 

@Andrew : thanks for the cool MRI pics and info !    Didn't think a service tech would have to play the janitor, nor be the one actually OPERATING the thing !    I thought you had to be doctor to do it...

@Rob : wow, 20+ current clamps, you're the man !   I have yet to do own just ONE clamp !  On the to buy list of course. At least I know who to ask when I will be on the market for one !

@Tggzzz : spray can with long straw is required ni my case... only realistic way to get to , and clean the millions of contacts in my old glowing Tek scopes. Full of wafer switches, all 10 stories long, each wafer with 2 dozen contacts all around them... only way is to spray the entire switches assemblies, and work them 2 dozen times.


Storage & sorting : this evening got my second batch of 60x100mm Kraft paper envelopes, so could complete my resistor box. Now have a complete set of envelopes for the E24 from 1R up to 10M.
Even though the vast majority of them are empty... the bow is already too tight.... need to make another one already, a bit longer... and spanning two columns 'cause once I buy new resistors to fill 100% of the envelopes, they will take a lot more volume still...

Made a little spreadsheet so I know what I have, values and quantities, see below. Well I have less stuff than I thought !   I have basically 2 almost complete decades only, and two decades half-populated. And the other decades..; pretty much nothing. Oops...   There are much more empty envelops, than populated ones... So I am thinking "plugging holes" in this box doesn't make much sense... might as well put all these crappy carbon resistors in storage / backup, and buy all brand new resistors, 1% metallic, and standardize on that.

Now have many envelopes left over... think they might be useful to hold other components like a little collection of  Zener diodes for example...

[Cerebus]

We still have diesel powered trains moving shit-tonnes of coal, shaking the house every few days , not sure exactly where it goes after the sidings. Most coal power generation in the UK has gone bar a couple of stations.

Over the last year, UK average electricity production from coal was 568 MW out of an average from all sources of 30.805GW, so 1.84% (gridwatch.co.uk). That's up quite a bit on the previous couple of years (not sure why) and down a lot on a few decades back. Current figures for world electricity production is around 41% from coal.

So that 568 MW of coal fired electricity equates to 4.98 TWh of electricity, call it 5 TWh out of a total of 270 TWh from all sources. It takes 14 tonnes of coal to make 45 MWh of electricity, so that 5 TWh represents 111,111 tonnes of coal, which sounds like a lot, but probably isn't much in terms of freight trains full of coal. Anyone have any idea how much coal in one of those trains?

[factory]

We still have diesel powered trains moving shit-tonnes of coal, shaking the house every few days , not sure exactly where it goes after the sidings. Most coal power generation in the UK has gone bar a couple of stations.

Over the last year, UK average electricity production from coal was 568 MW out of an average from all sources of 30.805GW, so 1.84% (gridwatch.co.uk). That's up quite a bit on the previous couple of years (not sure why) and down a lot on a few decades back. Current figures for world electricity production is around 41% from coal.

So that 568 MW of coal fired electricity equates to 4.98 TWh of electricity, call it 5 TWh out of a total of 270 TWh from all sources. It takes 14 tonnes of coal to make 45 MWh of electricity, so that 5 TWh represents 111,111 tonnes of coal, which sounds like a lot, but probably isn't much in terms of freight trains full of coal. Anyone have any idea how much coal in one of those trains?

The link to realtimetrains in my post quotes 1800 tonnes for the trailing load, but some of that must be the waggons, with an average of two trains a week on that route.
https://www.realtimetrains.co.uk/service/gb-nr:H20927/2022-02-07/detailed
And as I said before I don't know where it's going, as it doesn't go direct to the end user, instead to a freight sidings.

David

[Cerebus]

There is MRI safe janitorial equipment.   It is expensive --  ~$1000 for a mop and bucket.    -> http://ketteringsurgical.co.uk/shop/mri/mri-maintenance/dual-bucket-and-mop-system-12808.htm
Broom and dustpan is about £300 --> http://ketteringsurgical.co.uk/shop/mri/mri-maintenance/fiberglass-broom-handle-and-broom-heads-23704.htm

You've gotta laugh at the crazy markup on "special" stuff for technical purposes that could be substituted with "ordinary" cheap stuff. You can get tight arsed purchasing managers to shell out for this sort of stuff when you have a hard time getting an extra penny a roll out of them for toilet paper that doesn't shred your arse.

Yes, but...

The key bit of the first sentence is "could be substituted". Some could not. The question then comes down to who (and/or which organisation) makes the dstermination and is responsible if things go tits up.

Sometimes FUD is fully justified.

OK, pretend I said "that have perfectly acceptable substitutes in 'ordinary' cheap stuff" which is what I meant when I wasn't expecting someone to use my exact choice of words to justify highly dubious rent seeking.

And on the subject of choice of words, "FUD"  - coined for IBMs "Fear, Uncertainty and Doubt" marketing strategy - is a tactic used when one has no solid legitimate argument to support one's position. It's a very odd choice of word to try and argue is ever "fully justified".

[Cerebus]

We still have diesel powered trains moving shit-tonnes of coal, shaking the house every few days , not sure exactly where it goes after the sidings. Most coal power generation in the UK has gone bar a couple of stations.

Over the last year, UK average electricity production from coal was 568 MW out of an average from all sources of 30.805GW, so 1.84% (gridwatch.co.uk). That's up quite a bit on the previous couple of years (not sure why) and down a lot on a few decades back. Current figures for world electricity production is around 41% from coal.

So that 568 MW of coal fired electricity equates to 4.98 TWh of electricity, call it 5 TWh out of a total of 270 TWh from all sources. It takes 14 tonnes of coal to make 45 MWh of electricity, so that 5 TWh represents 111,111 tonnes of coal, which sounds like a lot, but probably isn't much in terms of freight trains full of coal. Anyone have any idea how much coal in one of those trains?

The link to realtimetrains in my post quotes 1800 tonnes for the trailing load, but some of that must be the waggons, with an average of two trains a week on that route.
https://www.realtimetrains.co.uk/service/gb-nr:H20927/2022-02-07/detailed
And as I said before I don't know where it's going, as it doesn't go direct to the end user, instead to a freight sidings.

David

OK, so if we assume that 1800 tonnes represents a conservative 900 tonnes of coal then that's 123 trains full a year for power generation (half that if it's net load). There's still a small market for coal for domestic and industrial heating, low grade stuff probably still gets coked for what little is left of the steel industry, and coal is still used as a minor chemical feedstock for some things. Sure sounds like there's a lot going somewhere we can't guess.

What happens to all this 'black' coal? 

[factory]

Some of it must end up getting used by heritage railways & other steam powered vehicles too.

The train that went through recently (in the video) had 18 wagons, GLW of each is 102 tonnes, minus the Tare weight of approx 27 tonnes, load could be a max of 75 tonnes and 1350 tonnes max load, those wagons are used for other materials too. 900 tonnes is probably more realistic, IDK what the weight of coal compared with stone, or ore, etc. that might be moved by the same type of wagons. Had enough for tonight anyway. 
 
Apologies for polluting the thread with this non-TEA content.

David

[Neper]

TE still has chassis and housings made of steel and steel needs coal (or the coke made out of this coal) to be produced from iron ore. So, you're not completely OT.

But it's the steel produced for cars and in the construction industry that gobbles up most of the coal imported into the UK.

[Carl_Smith]

I went back to the original screen because the touchscreen firmware is closed source and I couldn't be bothered re-writing the entire UI just to get it to a state where it supports all the Marlin features I need. I've configured and compiled Marlin 2.0.9.3 for the original screen and will use that until I get the motivation to re-write the touchscreen firmware (the day after never). PlatformIO is ok, but it's a bit buggy and I've found that it will sometimes retain/report errors that have been corrected until you completely close and re-open VSCode (that one had me occupied for at least an hour). Now I can get back to hardware things.

Btw: Marlin 2.0.9.3 source also has a few gotcha's to keep you busy. The main one being that the download Zip doesn't contain all the required include files for the STM32.

McBryce.

Don't know if TEA readers are familiar with the history of Lulzbot, but they started in 2011 in Colorado.  In the fall of 2019 they had major cash flow problems and ran out of money to make payroll, and laid off the majority of their people.  An investor in Fargo, ND, where I live, bought out the assets, trademarks, etc, of Lulzbot, and relocated the company to Fargo. Over 20 truckloads of stuff moved to a new building, and months setting everything back up to get the company set back up and restarted.

Anyway, the former owner of the company when it was in Colorado was a rabid open source advocate, enough so that no closed source software was allowed.  All their computers were Linux, etc.  No Windows, Office, etc...

So as I've heard it, and there may be holes and/or mistakes in my understanding, this applied to the firmware code too. So if you want open source touch screen code for Marlin maybe you should look at the Lulzbot branch.  Maybe you can pull code out of it for your use. As I understand it, the Lulzbot touchscreen code uses no closed source code. 
https://gitlab.com/lulzbot3d/marlin

So even though the touch screen for all the Pro line of printers and the Bio is based on the FTDI EVE controller, they used none of FTDI's proprietary UI design tools.  The re-implemented everything as open source.  All the code should be there to do whatever you want with FTDI EVE based touchscreens.

But, even though I work for Lulzbot and I'm getting into the firmware stuff, I haven't actually looked much at any of that part of the firmware yet so I don't know what's really there in the touch screen code and how it really works.  But I will probably be figuring that out someday soon.

[Andrew_Debbie]

With old HP stuff it's always a good idea to check for RIFA madness & Schaffner mains inlet filters, waiting to release that special scent. 
 
David

Agree.   I should have opened it before I applied power.   

No inlet filter.  No across the line capacitor.     The top cover screws were a bit corroded and had not been off in a very long time.

The +18V and Tracking potentiometers are damped.  The +6V pot is not. I thought maybe the damping grease had run out of it.  Instead, it looks like the +6V control never had damping or it was replaced. 
The damped controls have the correct HP part numbers on them.   I don't see it on the +6.   So either a good repair, or a production change.

[tggzzz]

Ah, don't you just love the auction house spam, this one from i-bidder...

Hi Tom, We noticed that you were interested in this item. COLLECTION OF THANDAR & QUARTZLOCK VOLTAGE EQUIPMENT / OSCILLIOSCOPES If you are still searching for an item like this -
here are some alternatives you might like.

• A COLLECTION OF ASSORTED PENKNIVES, CHEROOT HOLDER, PENS, COMPASS, PAIR OF CHILDS SHOES
• A COLLECTION OF SHOOTING EPHEMERA, TO INCLUDE CLEANING BRUSHES, MULTI TOOLS, OIL BOTTLE ETC
• A COLLECTION OF ASSORTED COMPASSES, TWO SILVER WATCH CASES
• A collection of 19th Century German hand carved Black Forest bear items to include two carved pipes, bottle toppers / topsor caps and corks.
• A collection of four 19th Century German Black Forest carved bears
• The Pearse Collection - an important and extensive archive of documents and items relating to a family of 17th & 18th century Christians - some of which were well known preachers of the period

... with the added twist that one of those lots is (currently) mine!

[BU508A]

Nice explanation of SMUs and how to use them:

[jogri]

Quick question for those who own a 617: How high is the bias current after warmup on your units? I've stumbled across a few posts on here claiming that the lowest 2 pA range is basically unusable due to the high input bias current, but my 617s are both at around 600 aA after warmup.

Did i just luck out and got the one good crate of 617s that left the factory or is that 5 fA spec just the "guaranteed to never exceed" figure?