Author Topic: Test Equipment Anonymous (TEA) group therapy thread  (Read 1827841 times)

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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30925 on: May 08, 2019, 03:46:52 pm »
Hmmm... the BNC ferrule isn't in any of his listings. And my 6100s didn't come with them.  :-//

Okay... I could've sworn I remembered rise time on the P2200 being rated at 1.5ns last time I looked into them.

Yeah, these all have pretty heavy capacitive loading. But that's the price of pretty much any cheap probe. :bullshit: 

Still beats breaking my last intact P6136 when the "penis fingers" lightning strikes close to home.  :-DD

Oh, crap, I remember now... it was the Wittig P201/P202 that "used to be" the decent cheap probes but are now unobtanium.   :palm:

I bought the 6100s as a "consolation prize" to be expendable daily drivers.

mnem
*glares angrily at the brain cell that bit of info was written on*


 

Offline tggzzz

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30926 on: May 08, 2019, 04:12:27 pm »
I managed to pick up a Muirhead cell from eBay a while back.

It's a shame it wasn't the dual cell version.

It's a bit younger than yours. Last time I checked it was against my brand new Brymen 867s. The temperature adjusted voltage should have been 1.01840V and the Brymen measured it at 1.018420V which is close enough in my book!

Like this (tee hee :) )






My best estimate is that the indicated voltage is 0.015% lower than reality, which is in spec for the meter and cell.
« Last Edit: May 08, 2019, 04:14:04 pm by tggzzz »
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30927 on: May 08, 2019, 04:44:42 pm »
And now for something completely... ON TOPIC!



Just tripped over this while looking at a broken TX6150 probe being offered for far too much money: eBay auction: #132914803345

mnem
 >:D
 
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Offline med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30928 on: May 08, 2019, 04:56:56 pm »
Speaking of scopes....

I mentioned the other day that the 7A24 plug-in in the 7904 showed multiple issues. Well, it's not the plug-in. The left vertical slot of the 7904 has a problem. This is the 7904 with 2 - 7A15 plug-ins. Identical settings on both plug-in's. Identical waveform. Left vertical at top. Exactly half the gain of the right vertical. So something fubar in the mainframe. I tried swapping the inputs directly to the scope's vertical amplifier and the problem stayed with the left. So the issue is somewhere in the interface between the left vertical plug-in and the scope mainframe. Diving in.....More to follow.

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Offline med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30929 on: May 08, 2019, 05:45:36 pm »
Gee....if only all fixes were that easy I'd be bored. Found the issue and it was indeed on the back plane where the plug-in and mainframe connect. PSU partially pulled out to gain access. That loop of 2 blue coaxes above the 2 with the tape were unseated to the back plane. Must have somehow happen when I pulled the PSU last week to fix it.



Here's the results. Fixed.  :-+

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Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30930 on: May 08, 2019, 05:48:37 pm »
Nice one. I love it when it's problems like that  :-+

 

Offline med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30931 on: May 08, 2019, 06:08:28 pm »
Nice one. I love it when it's problems like that  :-+

Definitely. It looks like I have all the issues with the 7904 mainframe fixed which is a relief. That puppy is heavy and hard to jackass around.  :phew:

Looks like all that's left is clean and compensation on the 7B26 and 7B24 plug-ins. Both showing some issues with their attenuator deck switches. 
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30932 on: May 08, 2019, 06:23:48 pm »
Dude... haven't you learned better than to say the a-word in here?  :-DD

Murphy is gonna hunt you down and club you to death with a Tektronix Attenuator assembly if you don't stop taunting him like that...  :o

mnem
And I'll post video on antisocial media.  >:D
 

Offline med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30933 on: May 08, 2019, 06:40:32 pm »
Dude... haven't you learned better than to say the a-word in here?  :-DD

Murphy is gonna hunt you down and club you to death with a Tektronix Attenuator assembly if you don't stop taunting him like that...  :o

mnem
And I'll post video on antisocial media.  >:D

Maybe so. And for all I know tomorrow the damn thing could burst into flames.  :scared: But right know I'm going to relish that the monster is quietly going through a burn-in and I'm going to bask in that warm Tek glow.  :-+ :-DD

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Offline factory

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30934 on: May 08, 2019, 09:00:45 pm »
I have an 'adequate' over supply of IEC and two core leads ;D One Milk crates worth.

These are a good thing for walls of low power TEA items too saves having to hide long leads ;) eBay auction: #321960389520 The ones I got tested fine for insulation, current maybe not so much.

Speaking of power cables, what's a reasonable way to check the quality of unknown ones without cutting them open? I'm suspicious of most cables included with consumer equipment made in the last decade or so.

Megger of some sort for insulation 1-5kV or my recent Test and Tag box albiet it tests at 500V.

Conductor rating of anything evilbay treat it like PMPO for Audiophools divide by two divide by the square of two then halve it again as a safety margin  ;) Or you could set up a low voltage DC load test I guess as it is easier and safety than a mains AC test.  :-//

Over here we have special TE for that, the PAT (portable appliance testing) machine, these can do the insulation checks and older ones could also measure the earth/ground wire resistance at 20A to find out if the earth continuity meet the spec for the wire type, diameter & length. This check used to weed out a few IEC leads every year that failed with poor earth continuity. The machine also found an IEC lead with reversed polarity.  :o

We used to have PAT (portable appliance testing) done in house at work, since it was outsourced two out of the three companies used have turned out to be complete cowboy outfits, they never seem to turn up with the leads for checking the earth continuity and also can't be bothered with the visual inspection, hence why nothing seems to fail any-more, but they complete the "sticker test" (as I now call it) in a tenth of the time it took to do it properly.  :rant:

I too ended up with far too many IEC leads, I dumped most of the no-name ones as I got given a box of unused older Volex ones (with the unsleeved plug pins).

David
 

Offline BU508A

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30935 on: May 08, 2019, 09:09:44 pm »
 :horse:
Anyone else end up with the situation where you have more test equipment than line cords? I did. So I fixed that by buying a bunch of line cords.  :-DD

I have more line cords than test equipement. I've bought some time ago a bunch of them.
The picture below shows just a few of them as an example.



And today I received a nice parcel with more than 3kg of Rohde & Schwarz parts.
I sniped them here: https://www.ebay.de/itm/362633010637



Have to check, what all this stuff is. If someone is interested in the RF parts, please let me know.  :)
« Last Edit: May 08, 2019, 09:15:45 pm by BU508A »
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Offline wch

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30936 on: May 08, 2019, 09:23:29 pm »
I got another hit from my CL WTB ad, a local ham saying he had a couple of TM plugins and frames he wanted to sell. 

When I met him today, he told me he decided to bring some other stuff, too. After going through the pile, I bought a TM502A, TM503A, three plugins, (a couple of power supplies and a DMM), two 8116As, a 6115A, and a P6046 probe, power supply, and amplifier in the original case.  The previous owner claims the P6046, 6115A and TM stuff all work, and said the 8116As "mostly worked", a position he retreated from when I mentioned error codes and custom HP ASICs. 

The whole lot cost me 110USD. So, am I an idjit, easily parted from my money? Probably, yes, even though I am expecting a 100 percent failure rate on the 8116As, the 6115, and the plugins and there's a fifty-fifty chance that the probe is junk.

But I look at it this way... I bought two 8116A lottery tickets and got four or five of the scratch off kind for free.  :-DD

That sounds like a pretty good haul to me, wch. How's the 6115A looking? I see many that have had a hard life with missing rear cover, bent fins, and scarred front panels made by gorillas chiseling off calibration stickers. :palm:

I am buried in paper of various sorts today and will post more on all this stuff once I have banished what must be banished.  The gear is generally in good shape.  The seller said the 6115A was blowing fuses but "worked before that". I will take photos of the teardown, figuring I am going to look for obvious problems then probe around for bad caps.  The good news is there is lots of 6115A experience around here and I suspect that whatever I find will have been seen before.

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Offline grizewald

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30937 on: May 08, 2019, 09:29:38 pm »
Fancy Muirhead my pair of D-845's are smaller format https://www.eevblog.com/forum/metrology/1000-my-(hi)story-of-the-weston-cell-of-the-volt-and-of-being-a-volt-nuts/msg1437815/#msg1437815

It is a bit hard to tell but there is some sort of barrier above the Mercury and so long as you keep it and the other Electrode point with a barrier between the Cell will function so there is no need for the seconds chamber. The downside is that if that likely sintered barrier allows chemical contact over time with the Mercury it will eventually fail or block the Capillaries in the barrier.  :-//

As tggzzz said in the other thread, the D-845 would seem to be an unsaturated cell, judging by the higher EMF. If it's still in spec after 58 years, you would appear to have something remarkable given that they are only supposed to be good for 37 years as a maximum!

I still don't understand how that Cambridge cell is constructed - time to do some research...
 
 

Offline Neomys Sapiens

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30938 on: May 08, 2019, 09:52:54 pm »
On the topic of the HP6825A - not the repair, but the manual. I did scan it in sections at 600dpi and fortunately my company has a scanner that can handle 'overlong' formats for the drawings. Then I assembled everything into a PDF using PDFcreator+. I kept that at 300dpi and enabled compression, but nevertheless it is a file of 57MB.
Where should I put it and how? My Firefox does not support KO4BB's upload via FTP. I can try IE from work.
 

Offline grizewald

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30939 on: May 08, 2019, 09:58:25 pm »
And it lives in a drop dead beautiful house!
You're a lucky guy indeed!

Thanks! It was a lucky find and it's in pretty much mint condition. It cost me all of 30 GBP.

I was frankly amazed to find a Weston cell for sale on eBay and even more surprised that the seller had no qualms about posting it from the UK to Sweden. (I certainly wasn't going to lecture him about the legality of shipping a package of distinctly harmful substances by air mail and cut myself out of the purchase!) I was quite apprehensive when I went to collect it from my local postal agent. I had visions of seeing a soaking wet package and having to reluctantly advise the guy behind the counter that he would need to close his shop and call in a hazmat team to decontaminate the place while he was at the hospital being decontaminated himself!  :scared:

Thankfully, it somehow survived the trip and after some silver polish on the terminals to remove the black oxidation and wiping down the case with a damp microfibre cloth, it was restored to its original glory. Chemically, I expected the cell to survive the trip without trouble as Muirhead incorporated a porous polythene disc in each arm of the H to keep the various chemicals in place, even during transport upside down.

I have no idea where it came from and sadly the seller didn't have the original calibration certificate. It has certainly never been abused and while it's no LTZ1000, it does seem to develop the expected EMF once adjusted for temperature, so it's still useful as an ultra low noise sanity check in the absence of a recently calibrated standard.



 
 

Offline tautech

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30940 on: May 08, 2019, 09:59:40 pm »
On the topic of the HP6825A - not the repair, but the manual. I did scan it in sections at 600dpi and fortunately my company has a scanner that can handle 'overlong' formats for the drawings. Then I assembled everything into a PDF using PDFcreator+. I kept that at 300dpi and enabled compression, but nevertheless it is a file of 57MB.
Where should I put it and how? My Firefox does not support KO4BB's upload via FTP. I can try IE from work.
A vote for Ebaman.
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Create an account and upload.
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Offline grizewald

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30941 on: May 08, 2019, 10:01:00 pm »
On the topic of the HP6825A - not the repair, but the manual. I did scan it in sections at 600dpi and fortunately my company has a scanner that can handle 'overlong' formats for the drawings. Then I assembled everything into a PDF using PDFcreator+. I kept that at 300dpi and enabled compression, but nevertheless it is a file of 57MB.
Where should I put it and how? My Firefox does not support KO4BB's upload via FTP. I can try IE from work.

I used the site's "upload applet", which is actually just a dynamic page, from Firefox on Linux without problems.
 

Offline tggzzz

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30942 on: May 08, 2019, 10:40:57 pm »
And it lives in a drop dead beautiful house!
You're a lucky guy indeed!

Thanks! It was a lucky find and it's in pretty much mint condition. It cost me all of 30 GBP.

I was frankly amazed to find a Weston cell for sale on eBay and even more surprised that the seller had no qualms about posting it from the UK to Sweden. (I certainly wasn't going to lecture him about the legality of shipping a package of distinctly harmful substances by air mail and cut myself out of the purchase!) I was quite apprehensive when I went to collect it from my local postal agent. I had visions of seeing a soaking wet package and having to reluctantly advise the guy behind the counter that he would need to close his shop and call in a hazmat team to decontaminate the place while he was at the hospital being decontaminated himself!  :scared:

Thankfully, it somehow survived the trip and after some silver polish on the terminals to remove the black oxidation and wiping down the case with a damp microfibre cloth, it was restored to its original glory. Chemically, I expected the cell to survive the trip without trouble as Muirhead incorporated a porous polythene disc in each arm of the H to keep the various chemicals in place, even during transport upside down.

I have no idea where it came from and sadly the seller didn't have the original calibration certificate. It has certainly never been abused and while it's no LTZ1000, it does seem to develop the expected EMF once adjusted for temperature, so it's still useful as an ultra low noise sanity check in the absence of a recently calibrated standard.

That last point is my principal use for them, apart from them merely being kewl tech.
There are lies, damned lies, statistics - and ADC/DAC specs.
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Online beanflying

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30943 on: May 09, 2019, 01:36:00 am »
Fancy Muirhead my pair of D-845's are smaller format https://www.eevblog.com/forum/metrology/1000-my-(hi)story-of-the-weston-cell-of-the-volt-and-of-being-a-volt-nuts/msg1437815/#msg1437815

It is a bit hard to tell but there is some sort of barrier above the Mercury and so long as you keep it and the other Electrode point with a barrier between the Cell will function so there is no need for the seconds chamber. The downside is that if that likely sintered barrier allows chemical contact over time with the Mercury it will eventually fail or block the Capillaries in the barrier.  :-//

As tggzzz said in the other thread, the D-845 would seem to be an unsaturated cell, judging by the higher EMF. If it's still in spec after 58 years, you would appear to have something remarkable given that they are only supposed to be good for 37 years as a maximum!

I still don't understand how that Cambridge cell is constructed - time to do some research...

What is clear is that the assumptions and theory as to lifetime of Weston Cells going forward in and based on the 1965 Text do not hold up to actual empirical data over time. There is a bunch of factors after manufacture that effect life let alone the actual construction of them initially. So if you have one that works treat it kind and see how it is after 100 years, as a then 75 year old I hope to be able to test it  ;)

Re the Cambridge Photos and guesses on the construction here https://www.eevblog.com/forum/metrology/1000-my-(hi)story-of-the-weston-cell-of-the-volt-and-of-being-a-volt-nuts/msg2398591/#new

Overnight the 3DP part of the enclosure for the caseless Cell finished printing. Time for several coffees then boot the Laser into gear for the clear side clean up the print and add some fasteners.
« Last Edit: May 09, 2019, 06:47:19 am by beanflying »
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Offline 0culus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30944 on: May 09, 2019, 03:33:04 am »
All this talk about standard cells led me to reading about them, and what's apparently replaced them.

Weston cells definitely sound like "don't break it" material. About the only nastier thing I've seen is this stuff called "X-ray Fusion Flux", aka lithium tetraborate. Apparently even the hazmat crew wouldn't touch it.

Josephson standards OTOH, are much less nasty chemically.





[edit] for a real "worst of the worst" parade of the nastiest chemical compounds ever synthesized, Derek Lowe's blog is a fun read: https://blogs.sciencemag.org/pipeline/archives/2011/11/11/things_i_wont_work_with_hexanitrohexaazaisowurtzitane
« Last Edit: May 09, 2019, 03:40:10 am by 0culus »
 

Offline Carl_Smith

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30945 on: May 09, 2019, 03:55:17 am »
for a real "worst of the worst" parade of the nastiest chemical compounds ever synthesized, Derek Lowe's blog is a fun read: https://blogs.sciencemag.org/pipeline/archives/2011/11/11/things_i_wont_work_with_hexanitrohexaazaisowurtzitane

Very funny post.  Especially:
Quote
Although, as the authors point out, if you heat those crystals up the two components separate out, and you’re left with crystals of pure CL-20 soaking in liquid TNT, a situation that will heighten your awareness of the fleeting nature of life.
 
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Online beanflying

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30946 on: May 09, 2019, 03:58:03 am »
Cost of a bank of Weston Cells $1-2k, cost of a JJ Array $xxx,xxx+ ?  I won't be adding one to my Cal gear.  ;)

The worst chemical I have ever played with is HF https://msds.orica.com/pdf/shess-en-cds-010-000034430201.pdf A company I used to work for sold and serviced Pumps for a producer of it. Plenty of other nasties we worked with as well but this one eats bones with contact among it's other issues. Barrier cream on hands, double gloves, disposable overalls, full face forced respirators ......

Quote
Chronic effects:  Chronic low dose exposure to hydrogen fluoride by inhalation can lead to ulceration and perforation of the nasal septum.  Chronic exposure to excessive quantities of gaseous or particulate fluoride results in nausea,vomiting, loss of appetite and diarrhoea or constipation.  Fluorosis or other chronic effects may result from significantacute exposures.  Hydrogen fluoride is a calcium scavenger binding with calcium in the bloodstream and bones

Mercury is a lightweight  :o
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30947 on: May 09, 2019, 04:16:14 am »
DAMMITT, BEAN! STOP MAKING 3DP LOOK SO USEFUL!!!  :-DD

mnem
*toddles off to ded*
« Last Edit: May 09, 2019, 03:11:41 pm by mnementh »
 

Offline 0culus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30948 on: May 09, 2019, 04:25:50 am »
Cost of a bank of Weston Cells $1-2k, cost of a JJ Array $xxx,xxx+ ?  I won't be adding one to my Cal gear.  ;)

The worst chemical I have ever played with is HF https://msds.orica.com/pdf/shess-en-cds-010-000034430201.pdf A company I used to work for sold and serviced Pumps for a producer of it. Plenty of other nasties we worked with as well but this one eats bones with contact among it's other issues. Barrier cream on hands, double gloves, disposable overalls, full face forced respirators ......

Quote
Chronic effects:  Chronic low dose exposure to hydrogen fluoride by inhalation can lead to ulceration and perforation of the nasal septum.  Chronic exposure to excessive quantities of gaseous or particulate fluoride results in nausea,vomiting, loss of appetite and diarrhoea or constipation.  Fluorosis or other chronic effects may result from significantacute exposures.  Hydrogen fluoride is a calcium scavenger binding with calcium in the bloodstream and bones

Mercury is a lightweight  :o

I see your HF and elemental mercury and raise you organic methylmercury compounds. Ordinary protective gear does not work against this stuff.  :o You can put as many layers of latex and creams as you want on and it'll go right through, then proceed to kill you slowly over a period of a few months.

[edit] I figured new standards cost a king's ransom ahaha
 

Online beanflying

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #30949 on: May 09, 2019, 05:14:28 am »
Most 'interesting' job I did was supply a Hydraulic Drive Peristaltic Pump (40mm hose) with marine bronze fasteners for pumping Nitro-glycerine. 'Allegedly' it is safe providing it remains in an aqueous solution which is what we were moving. The isolated building was away from any others and surrounded by 12' high earthen barriers so I remain unconvinced. All tools in the building were also Bronze to avoid sparks  :o

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