Test Equipment Anonymous (TEA) group therapy thread

[0culus]

No problem! I will definitely be using one for my next build. My last build I made the mistake of using the Fractal Design R3 (iirc). Great looking case with tons of hard drive bays but HEAVY as HELL even without PSU, motherboard, CPU cooler, and hard drives.... 

[beanflying]

That Case alone would be more than I paid for the current shack PC I do my CAD on  Far to nice for me.

[bitseeker]

yeah but I have a 'mini CAL LAB' that needs a proper test unit. Gotta have a NIST & current CAL at least 7.5 digits res, hard to find under a few k.

In case you hadn't seen it before,

http://www.conradhoffman.com/mini_metro_lab.html by forum member Conrad Hoffman

And some discussion in the thread, Mini Metrology Lab Build (update). I'm sure you'll find plenty more in the Metrology forum.

[beanflying]

While it may seem OTT for home use to not have at least a 1 off superior meter to Cal the rest of your fleet to you really have zero idea of if it is or isn't a Volt, Amp etc. I am now relying on a 34401A that fell out of Calibration over 2 years ago not ideal but that is 'currently' my best reference soit is either a 3458a in Cal or it will be taking a Road Trip to Keysight soon.

Conrads stuff is great btw I have some custom Resistors coming from Edwin Pettis for a Hamon Divider based on his notes.

[mnementh]

Welp, the Thermaltake V200 is here... and I have to say, I'm underwhelmed. I know they're a cheap Dongguan manufacturer, born of a cheap Taipei manufacturer... but everything I ever bought from them always felt like... twice as good as the money I spent. This case feels like $39 Rosewill that nobody would buy until it went down to $29. Shipped. 

Hey, I resemble that remark. The Media PC is in the $39 Rosewill case.  I didn't find it to be feel cheap or poorly built. Everything fit as designed with minimal hassle. Granted, that was my first and, so far, only scratch built PC so I really don't have anything to compare it to but I'm satisfied with it's overall construction and there's been no issues in almost 4 years. 

I've built more Rosewill boxes than I can count... for other people. But they are pretty cheap, and the finish of their plastics is pretty cheesy, and a LOT of their design aesthetic is like... "How can we make a case that looks like a chainsaw fucked a lobster cage?" 

I am a fan of Lian Li aluminum cases. They have great fit and finish and are lightweight. Perfect for a tower that may have to get moved any at all.

I agree... and I Like NZXT's workstation cases as well, when there's more budget.  I'm just trying to give myself a little leeway in case I actually do have to do a complete new build.

I am a fan of Lian Li aluminum cases. They have great fit and finish and are lightweight. Perfect for a tower that may have to get moved any at all.

Oh hell yeah, this is SEXY.   https://www.newegg.com/Product/Product.aspx?Item=9SIAFST88T0454&Description=lian%20li&cm_re=lian_li-_-11-112-588-_-Product

great tip, thanks mate.

I looked at the black version of that case and if it'd had a hinged front, I'd have probably gotten it. 

That Case alone would be more than I paid for the current shack PC I do my CAD on  Far to nice for me.

The Lian Li? It's $89 shipped. Can't beat that with a stick. 

mnem
*Toddles off to ded*

[Inverted18650]

yeah but I have a 'mini CAL LAB' that needs a proper test unit. Gotta have a NIST & current CAL at least 7.5 digits res, hard to find under a few k.

In case you hadn't seen it before,

http://www.conradhoffman.com/mini_metro_lab.html by forum member Conrad Hoffman

And some discussion in the thread, Mini Metrology Lab Build (update). I'm sure you'll find plenty more in the Metrology forum.

most the time I am loged in (90% at least) I am on the Metrology tab. Love those high precision volt-nuts.

[Gertjan]

Anybody able to read German ?

My Rohde&Schwarz SMPD (Signal generator) is giving me error 6 now. So error 6 is "FM oscillator cannot synchronize". So I took the FM stage out to investigate and got that sticker on the side. 

The sticker says: "Align Casette (=unit, plug-in) after mounting". So it means that the electronics in this box have to be aligned / adjusted after the unit is plugged into your SMPD.

Hope this helps....
regards, Gertjan

[beanflying]

Surprising what I thought would be a cloned Handle and Bumpers from evilbay for my 34401A turned out to actually be secondhand 'as advertised' ex China  Either that or it came from a very grubby factory 

[0culus]

A few pics from inside my bum 8568B RF unit. It's quite clean inside because the seller cleaned it up before attempting to troubleshoot it. At this point, I'm quite sure there's something going on either with the OCXO or related circuits because the "climbing noise floor" problem visible in max hold goes away with external 10 MHz ref.

Looks to me like the front panel is going to have to come out to get to the partially failed attenuator. Job for another day. 

And finally, the biggest WTF. Note the little metal cylinder? That should be attached to the OCXO...but when I opened it that nub was stuck in the decidedly not OEM hole in the rubber grommet and the OCXO was completely knocked out of place. Related to the noise problem? Who knows. 

[bitseeker]

Surprising what I thought would be a cloned Handle and Bumpers from evilbay for my 34401A turned out to actually be secondhand 'as advertised' ex China  Either that or it came from a very grubby factory 

Good to know. I've seen listings like that before and been suspicious, too.

[VK5RC]

Volt-nuttery is a long and dangerous path, even with a 3458A, the 8 1/2 digits is a bit of a stretch. The standard 3458 is 8ppm/yr ie close to 5 digits of real 'accuracy', the 8 1/2 refers to transfer repeatability. Cabling, connectors, thermal issues, EMI etc all play merry hell with your sense of absolute accuracy in the region of a handful or so of uV in the 5-10V DC range ie 6 digits of true accuracy.
My 3458A is in cal, I have 16 LTZ references.  Nine of them have been switched on continuously (UPS) for about 15 months or so. The most recent lot - about 5 months.
To do a good 'measurement' run takes about a day to 'warm up', an hour of switching off almost everything in the shack and cleaning the terminals/cables.
Even then, 3 or 4 of the better references will reliably be within the +/-  2 to 4uV of what I think they should be.
I have been surprised how good a bog standard 34461A has been. Often within 10 to 15uV - but I didn't record it's results like I did for the 3458.
An interesting and ongoing experiment.
Rob

[0culus]

Volt-nuttery is a depth of TEA that I'm going to try to stay away from. 


 

[bitseeker]

It's a trap!

[beanflying]

It is indeed a slippery slope but I am enjoy the ride  Some of what I do needs better than 4.5 digits with good accuracy so I got the 34401A but to keep the 34401A in good nick I need a better meter 

There is no climbing out of this rabbit hole.

[Wolfgang]

34470A ? Its almost as good as a 3458A, at a fraction of the price and its *modern* with all the amenities a good meter should have *today*.
I like it, and there is still some TEA in it. Maybe they renovate the 3458A some day 

[beanflying]

34470A ? Its almost as good as a 3458A, at a fraction of the price and its *modern* with all the amenities a good meter should have *today*.
I like it, and there is still some TEA in it. Maybe they renovate the 3458A some day 

And that is why the 3458A is still desirable  necessary

[Wolfgang]

... well, then you need to go for the Fluke. Its 3ppm instead of 4ppm for Keysight. I you have got TEA, this is a hell of a difference ! 

[Brumby]

..... but to keep the 34401A in good nick I need a better meter 

... and there's the slippery slope!

[VK5RC]

The 34470 looks very nice, perhaps its biggest 'fault' from the volt-nut world are the terminals - the modern recessed type. Crimped 'naked virgin' gold plated tellurium copper lugs on teflon twin shielded cable - do seem to be a bit better than the average banana plug cable - but fresh copper (from stripped cat 5 cable) held in place by a cotton bud (Q tip), TiNs favourite, also does well.
The really silly thing is I don't think I have ever needed to measure voltage to more than 3 digits (volt-nut heresy) - but I am a TEA!

[beanflying]

The Fluke 8508A would be nice but they are even a more rare form of Rocking Horse Poo and come with a price tag meaning you may as well go buy a full blown calibrator and be done with it and grab a 2nd mortgage on the way past

[Specmaster]

Volt-nuttery is a depth of TEA that I'm going to try to stay away from. 


 

If thats the case then stay away from anything higher than 5.5DMM, better still don't go higher then 4.5DMM

[med6753]

All this discussion is exactly why I refuse to go any further than 5.5 digits with my volt nut. To go any further is a rabbit hole with no bottom. I like all my multimeters to match to the very last digit. At 5.5 digits and beyond they won't. There will always be some uncertainty and anal me will be continuously annoyed by that.   

And that's also why the calibration references I'm building or have built I consider only accurate enough to calibrate 3.5 and 4.5 digits. Beyond that and without a traceable standard I'd be tweaking and adjusting forever.     

[beanflying]

Just set up a bank of Standard Cells and look after them. Used to be good enough for NIST (secondary reference) until the late 80's.

Link is back available after being shutdown for a few weeks  https://www.nist.gov/sites/default/files/documents/calibrations/sp250-24.pdf

More Bed Time reading https://www.nist.gov/sites/default/files/documents/calibrations/mn84.pdf

[med6753]

Volt-nuttery is a depth of TEA that I'm going to try to stay away from. 


 

If thats the case then stay away from anything higher than 5.5DMM, better still don't go higher then 4.5DMM

Looks like you and me are on the same wavelength. Besides, volt nut is secondary to my primary TEA passion......oscilloscopes. 

[med6753]

Just set up a bank of Standard Cells and look after them. Used to be good enough for NIST (secondary reference) until the late 80's.

Link is back available after being shutdown for a few weeks  https://www.nist.gov/sites/default/files/documents/calibrations/sp250-24.pdf

More Bed Time reading https://www.nist.gov/sites/default/files/documents/calibrations/mn84.pdf

Holy crap.....I'd have to become a hermit to do all that shit correctly.  As it stands now my friends/family think I'm a little strange. 

Edit....and also why I stay away from the Metrology forum. I'd too easily get sucked in and never come out.