Test Equipment Anonymous (TEA) group therapy thread

[Neomys Sapiens]

Thanks a lot for the offer, but I need parts that appear on the NASA parts list. I am builing an USOs that is supposed to be space qualified, so a lot of parts are not even allowed. So for the types, that are 2N2222, 2N2857, 2N2848, 2N3866, ...
really retro, I know. Other parts may be even better, but you know the space buerocrats.

Is it possible, that you could post this parts list here? Just out of curiousity.

Thanks.

Yeah, why not. The link is here:
https://nepp.nasa.gov/npsl/

It also has links to the European and Japanese Space Agency Lists. Dont be surprised that some parts are older than you

Who still manufactures those devices to those Mil-Spec standards...?  To get that rating is more than just final parts testing; it's a whole process, from beginning to end that has to be maintained in closed-loop management to ensure the part is sufficiently abuse-tolerant.

After that, there's a whole nuther long involved process in the procurement aspect; from storage conditions to static-protection to chain-of-custody at every step of the part's handling to ensure it ARRIVES to the assembler without degradation. The last one left that I knew of back in the day was Fairchild; to my knowledge they no longer have US-based production facilities so would not qualify from the security aspect of that process control...?

mnem
*just me fulminating at the mind again...*

I think one of the major MIL parts supplier today is Microsemi.

And, yes, for class 1 you need backtrackability from the part back to the wafer. including all processing steps, tests, ...
No wonder a 2N2222A with all the checks will cost you about 1K per piece. You get a telephone book of documentation with it,
and you have to wait a few months before you get it. And - most surprising - the data of these parts is not as good as standard parts.
Only the have proven that they can survive a lot more abuse than others. Thats what you want in a space environment. Reliability is king.
Cutting edge ? Nah. Never.

Also Crystalonics, TT Group, Central Semiconductor, Lansdale, Teledyne E2v, American Microsemiconductor,  Aeroflex, Austin Semiconductors, GE Aviation Systems Semiconductor Products, Semelab, Semicoa, Semtech, Sensitron, Solitron Devices, Semtex Industrial,  Semiconductor Technology Inc., Silicon Transistor Corporation (STCsemi), Omnirel.

The area has been taken up mainly by smaller companies, as the reduced military volumes coincide with other influences like the agressive TI 'plastic-Mil' program. Also, some other sources are not semiconductor manufacturers per se, but former Distributors, which commission the parts and split the work between the manufacturer and a specialized test house. You can get parts from Linear Systems, Diodes Inc., Calogic, Cissoid that way or the parts are made by pure fabs without own portfolio which hold the necessary qualifications. As mentioned, some of the burden has been taken over by test houses, especially where Rad-Hard parts are concerned.

The QPDs (Qualified Products Databases) which are on https://qpldocs.dla.mil but also linked where the QPLs formerly were on ASSIST are always a good source for components, because you get an idea who is basically qualified and can be asked to take something up. For that, I prefer the older, last QPL that was issued, because you get at the manufacturers names without making multiple queries. The open access on ASSIST Quicksearch should be sufficient for most purposes.
Here you get at all parts that are covered by SMDs (Standard Microcircuit Drawings):
https://landandmaritimeapps.dla.mil/Programs/MilSpec
(Don't be put off by the name - they do space qualified part too)
Also the /Resources on that site has good cross references.
Also here: https://www.doeeet.com

Sometimes it is not so easy. For example take the US Naval Sea Systems Command, which is a giant organisation ....with a shiny website devoid of interesting content. it is not until you know that the work is done in their so-called warfare centers and you know which one, that you know where to go. For example, the Aegis system is handled by the Naval Surface Warfare Center Port Port Hueneme, and it is not before you go there AND then descend into the departmental structure that you find anythind meaningful. USAF is even worse - their AMC is simply byzantine. If you ever know what is the real name of a activity, do not lose this knowledge so that you can find it even if the structures above it change.
It also helps to have some contacts to specialized distributors like MSA Components, TTI, Charcroft etc., as they often know sources even if they do not represent them.

[Saskia]

I propose soaking the PCB in "Essigessenz" and wait for the bubbling to subside. This neutralizes the KOH and basically stops the caustic from eating any further into your PCB.

If it has been there for any time it won't be Potassium Hydroxide any more, it will almost certainly have converted to Potassium Carbonate by taking up CO₂ from the atmosphere - remember that alkali metal hydroxides are used to make CO₂ scrubbers to remove CO₂ from the atmosphere in rebreathers and spacecraft. It isn't necessary to do anything so aggressive as trying to neutralize it with vinegar. Potassium Carbonate is basically the Potassium version of washing soda (Na₂CO₃) and it ought to wash out quite happily with just water - it's so soluble that it's deliquescent. Adding an acid to the mix could make things worse by attacking things that are susceptible to acid attack that weren't susceptible to attack by bases. In particular, copper is more susceptible to attack by weak acids (e.g. vinegar) than is it to weak alkalis (e.g. K₂CO₃) - I use citric acid to micro-etch copper when making PCBs to promote adhesion of resist films.

I tend to disagree here given my experience with battery induced corrosion on PCBs and corrosion repair. When doing corrosion repair on a pinball pcb the KOH eats away at the traces even under the solder mask quite happily and does so for weeks if not longer. The only viable way to get it off is to neutralize it an a weak acid, and you can basically watch that reaction when pouring acid onto the board. We usually keep it on the board until the bubbling stops (which is about 10 seconds max, far shorter than any bases have had a chance to wreak havoc), clean it off, throw it into the ultrasonic and then remove the solder mask and use the proper amount of flux to clean off any corrosion. Then inspect it under the microscope and fix the traces.

This has worked for many dead CPU boards so far. Thus my offer.

The bubbling you observe is pretty conclusive proof that you're looking at the carbonate K₂CO₃ + 2CH₃-COOH →  2CH₃COOK + CO₂ + H₂O whereas the hydroxide doesn't produce any gas when neutralised CH₃COOH + KOH → CH₃COOK + H²O. The (weakly basic) carbonate is no more difficult to wash off than the (weakly acidic*) acetate that you're creating. All the neutralisation step is doing is introducing another unnecessary chemical to the mix.

* It's a little more complicated than that, potassium acetate in the presence of acetic acid acts as a pH buffer and it gets a bit complicated from there...

I get that. However if you do not treat it, it will continue eating away at the traces. At least that's what we learned from experience. I don't mind giving it a quick wash. If you think this is unnecessary, that's absolutely fine with me. it won't keep us from continuing with our quite successful repairs, and I think the main thing is that the board is working afterwards. Everything else is negotiable.

The ultrasonic will do a deep cleaning. Any additional bases will be neutralized by the flux treatment which will get rid of the oxidation. Tinning should follow, and naturally you want to get rid of the flux residue because it's just so damn icky. Could be caused by my using Amtech NC559 Tacky tho 

[Specmaster]

4503 UPDATE - Don't shout to loud but it looks I have it beaten now, took the Caddock resistor bank out and checked it out of circuit, all OK, did the same with the relays, checked out OK, reflowed some solder joints, switched it on, the 9M reading on ohms when in the auto range with open leads has gone. Calibrated OK on ohms and DCV, readings are spot on. ACV is still a bit off, 238V mains reads as 232V. I think I'll reassemble the meter at this juncture as the manual says to calibrate the AC with all the screening and case sealed up, so thats what I'll do. Need to check the ASC and DC current as well yet, fingers crossed.                                                                                                                                                                                                                  

[med6753]

4503 UPDATE - Don't shout to loud but it looks I have it beaten now, took the Caddock resistor bank out and checked it out of circuit, all OK, did the same with the relays, checked out OK, reflowed some solder joints, switched it on, the 9M reading on ohms when in the auto range with open leads has gone. Calibrated OK on ohms and DCV, readings are spot on. ACV is still a bit off, 238V mains reads as 232V. I think I'll reassemble the meter at this juncture as the manual says to calibrate the AC with all the screening and case sealed up, so thats what I'll do. Need to check the ASC and DC current as well yet, fingers crossed.                                                                                                                                                                                                                

Must have been some contamination on the board. I had some similar issues with a Fluke 8010A and I had to eventually replace the resistor network for discrete resistors to completely fix the problem.

[Specmaster]

4503 UPDATE - Don't shout to loud but it looks I have it beaten now, took the Caddock resistor bank out and checked it out of circuit, all OK, did the same with the relays, checked out OK, reflowed some solder joints, switched it on, the 9M reading on ohms when in the auto range with open leads has gone. Calibrated OK on ohms and DCV, readings are spot on. ACV is still a bit off, 238V mains reads as 232V. I think I'll reassemble the meter at this juncture as the manual says to calibrate the AC with all the screening and case sealed up, so thats what I'll do. Need to check the ASC and DC current as well yet, fingers crossed.                                                                                                                                                                                                                

Must have been some contamination on the board. I had some similar issues with a Fluke 8010A and I had to eventually replace the resistor network for discrete resistors to completely fix the problem.

Yes, I think you're right. I had already thoughly scrubbed this board, both sides with 99.9% Isopropyl. I still can't physically see any contamination anywhere but under the microscope there are a number of joints where the solder has not fed through the holes very well as the leads in them are tight. It is not easy to get a soldering tip into some of these joints on the component side due to the close proximity of other parts, so I may have to resort to flooding the area with liquid rozin and using the hot air gun to try and flow some solder to make sure of a good connection to the top pads . But first lets stick it back in the case and see how it goes.

[Cubdriver]

4503 UPDATE - Don't shout to loud but it looks I have it beaten now, took the Caddock resistor bank out and checked it out of circuit, all OK, did the same with the relays, checked out OK, reflowed some solder joints, switched it on, the 9M reading on ohms when in the auto range with open leads has gone. Calibrated OK on ohms and DCV, readings are spot on. ACV is still a bit off, 238V mains reads as 232V. I think I'll reassemble the meter at this juncture as the manual says to calibrate the AC with all the screening and case sealed up, so thats what I'll do. Need to check the ASC and DC current as well yet, fingers crossed.                                                                                                                                                                                                                

Must have been some contamination on the board. I had some similar issues with a Fluke 8010A and I had to eventually replace the resistor network for discrete resistors to completely fix the problem.

Yes, I think you're right. I had already thoughly scrubbed this board, both sides with 99.9% Isopropyl. I still can't physically see any contamination anywhere but under the microscope there are a number of joints where the solder has not fed through the holes very well as the leads in them are tight. It is not easy to get a soldering tip into some of these joints on the component side due to the close proximity of other parts, so I may have to resort to flooding the area with liquid rozin and using the hot air gun to try and flow some solder to make sure of a good connection to the top pads . But first lets stick it back in the case and see how it goes.

I'd be inclined to use 70% IPA, too - sometimes it's a better solvent than the nearly pure stuff because there are some things that won't dissolve in alcohol, but will in the water contained therein.

-Pat

[bd139]

So true. You just end up with sticky crap over everything with 100% 

[Kosmic]

Okies... show of hands.

April 15, I ordered a 10-piece lot of my favorite D-Sun MP1584EN buck converter boards for... stuff. Vendor shows 2-5 week delivery time, but updates in a few days with a Tracking number. Well, FF to this morning, I notice the delivery is now a week past the latest delivery date in the listing, and the tracking still shows as "en route to carrier". So they created a shipment, but either never shipped or more likely are just using that number to satisfy eBay requirements to be able to mark as "SHIPPED" and actually sent it some manner that isn't tracked.

I start a resolution, asking for a refund as I figure after 6 weeks I've been reasonably patient already; the vendor replies crying COVID delays and asking that I wait another 2 weeks. Since I already have a resolution process open, do I give the guy a break, or is 3 weeks late just unreasonable, even with COVID delays...?

mnem
 

I'm still waiting for my orders from China that were placed in March.

It's probably coming next month, I'm receiving February at the moment 

[xrunner]

Crap. This thing is noisy. I mean really noisy. I can barley touch any knob or tap on a board and the signal gives a flash of noise.

This is going to require a lot of cleaning and pulling every connector off.

What did I get myself into this time. 

[worsthorse]

https://www.aliexpress.com/item/10000199637975.html

Ummm... oklay... so this isn't the correct vendor on AliEx anymore...? Or is the difference that the ones being sold on the Tindie Store have been "calibrated"...?

Kindof discouraging, especially since they're now showing 144 pieces in stock with delivery by end of June...   

mnem
 

Hmmm... okay. Buy a nanovna from hugen on his aliexpress page. That's the real deal and there are two screen sizes, the bigger of them is 4".  There's a designer here  (OW something or other), Gabriel, who designed another version for a client. I think he was focused on improving its high frequency end performance.

I have both the small and larger versions of the Hugen nanovna and an SDR-KITs VNWA 3 and have used each side-by-side. The nanovna is a good rough and ready VNA, at least below 100MHz. It has lots of flaws... cheap connectors, limited number of data points, weird little measurement inconsistencies. That said, for fifty bucks or whatever it costs now it is a serious bargain, especially if you are just learning about VNAs, want a VNA that you don't have to worry about blowing up, or are doing hobbyist level measurements, especially below 100MHz.

If you are a measurement nut you will hate it. If you want to figure out whether the filter you just built meets spec, it's valuable.

EDIT: Disclaimer: I love weird little cheap test equipment. I have a stack of stuff from Autek, Palomar Engineers, etc that are a lot like the nanovna... kinda good at one thing, not very expensive, often exasperating, and yeah cute as a button small. So my thoughts might be biased.

Yeah, okay. Now we've come back full-circle to my original post asking if that was the correct vendor on AliEx.  There are several vendors supposedly selling the V2, and several supposedly selling the Hugen NanoVNA.   

The one above supposedly has the V2 IN STOCK now, while the Tindie Store listing I saw in here says out of stock for the last 6 weeks and months of delay before they get to you: https://www.tindie.com/products/hcxqsgroup/nanovna-v2/

mnem
 

sorry, i guess i missed the beginning of the thread. here's hugen's webpage:

https://www.alibaba.com/product-detail/Hugen-NanoVNA-H-New-item-Original_62342877955.html

The trading company is wuyi zeenko industrial and Maggie King is the contact person. She will bill you through paypal if you don't want to give your info to alibaba. 

[Kosmic]

Returned the Heathkit IG-18 sine / square wave generator to the owner this morning. I wanted to show him the sine wave output amplitude as related to the Int. / Ext. 600 ohm termination - I asked if I could use his scope. He said yea sure but it hasn't been on in years. I was able to use it but the controls were very dirty, as was the whole unit. Really filthy.

I asked him, if the scope worked well, would he use it? He said he would. So now, I have another project - restoring a Kikusui 20 MHz scope to full operation. I think it just needs a little TLC, no - a lot. Check the pics. One of the dirtiest scopes I've seen in a long while. Right now the cover is off and its airing-out on the front porch. 

Oh dear... here comes another installment of "experiments with bleach paste & UV light"; lemme pull up a chair and get comfortable... 

mnem
 

I might be able to produce the second episode. Got a yellow case and some new UVC lights 

[worsthorse]

The 184 saga continues...sometimes the HF function is showing signs of life but not much. Time to do a deep dive through the manual to try to figure out how it works. I also nearly had an electroboom moment when I accidentally connected the wishbone shaped inductor on the 500MHz board to chassis with my hand when I was moving the thing around. That inductor has +125V on it and it sure woke me up.  Decided it was time to put things away at that point...

This post made me all nostalgic for the 184 travails. Mine sits, still unfixed, on the shelf. Yes, I just gave up as the changing symptoms and intermittent changing failure finally best me. I hope you get yours working....

[Specmaster]

So true. You just end up with sticky crap over everything with 100% 

Oops sorry, I meant 70%, I don't have any stickiness at all on the board.

[Kosmic]

Cheap Power Designs 2005a on ebay (50$): https://www.ebay.com/itm/PD-Power-Designs-2005A-Benchtop-Precision-Power-Source-0-20VDC-0-500MA/274380272361

[0culus]

Wow. I might jump on that as a nice repair project.

[beanflying]

I hate seeing this sort of shit     

you can sold fixe that with special aluminium welding rods

Probably not. That's a die casting and the aluminium alloy used for die casting has a lot of silicon in it. It makes it expand ever so slightly as it freezes - which is great for die casting, but lousy for welding. When welding it as it all freezes the base casting metal expands, the filler metal shrinks and the whole thing either bends out of shape or in extreme cases just cracks again.

You can "stitch" cast ally back together using lead, but on something that small...  idk.   Only seen it used on HGV engine blocks.
EDIT: This link might provide some useful clues/inspiration?  https://www.metalockengineering.com/en/typical-repairs/metal-stitching/

It can be done with a dirt cheap butane torch and some filler rods and patience  https://www.eevblog.com/forum/testgear/hewlett-packard-740b-dc-standard-digital-voltmeter-(and-740a)/msg1419955/#msg1419955

Mmmmhmmmm... that project was one of the better soap operas to appear in this channel. 

I cringed when you modded in that C14 socket, even tho I knew it "had to be done".

I forget... did you ever finish the I/O boxes, or are the cable end connectors still holding you up...?

mnem
 

The Box design will be fine as per the thread, the 1kV rated multipole connectors I haven't found a price that meets my budget as I would most likely look at replacing both pairs  The reality is it would seldom get to 1kV so I could always just do a cheat with some 3-400V rated ones for the cost of only half an arm instead of both.

I still hold a minor hope of finding Rocking Horse Poop and buying the second box but if it came as a Pair Pat and I could most likely both be very happy 

[Cerebus]

As promised, E3610A pics.

First, the obligatory front panel glamour shot:


Basically looks new. This is essentially how it looked out of the box. It's got an Atmel asset tag and everything is so clean and unmarked that either this sat in a storeroom and was rarely if ever used, or Atmel employees really take care of their employers kit. It had a pristine "For Indication Only" sticker on and the original unbroken Agilent factory calibration seal on the back. What looks like some discolouration is just in fact my crappy lighting which is a mix of two colour temperatures.

Inside:


Again, very clean. I wiped out a very little dust with a tack rag and got the usual slight film of dark electrostaticly clingy dust off the inside of the lid with a couple of wipes. Basically the lid of my laptop gets dustier in a week than the inside of this was.

Finally, the money shots. Remember, this machine looks like it has never seen a calibration since it left the factory.


Yup, bang on.

As I said before, I was robbed, absolutely robbed, by having to pay £82 smackers for this. Lordy, I do like to just throw money away don't I? 

For reference, the vendor mel_ps was good, even checking with me when Hermes seemed to be taking longer than he was expecting with moving it around. Poor lad was under the impression that Hermes 1 day service might actually deliver in one day rather than the four they took and he took the time and trouble to send me tracking details on day two. Bless, such naïvité.

[xrunner]

Yep very nice one. The built-in meter they have isn't half bad either. 

[bitseeker]

Thanks for the update. The suspense was killing me. 

Added to POI.

LOL sorry. Thanks for adding it.

To note: Anyone reading these tips out there and wanting to try them - take account of your skill level and do so at your own risk. Much of the equipment you see in these threads is 10, 20 or more years old and replacement parts cannot easily be obtained. Any number of unforeseen problems can arise by taking them apart and attempting to repair or make them work better. On the other hand - the rewards can be great. Good Luck!

There, now I can rest easier. 

No problem. When I added it, I also included a mini-warning next to the link.

[bitseeker]

Edit: random "fuck microsoft". Windows Defender is giving me trouble today falsely flagging newly built and signed MSI packages on desktops but not on their own malware service. Grr. Utter tosser it is.

Hehe. My work laptop (Win 10 Enterprise) since March hasn't been able to update because it can't find Microsoft's update servers. Same old Windows, different day.

[0culus]

Cheap Power Designs 2005a on ebay (50$): https://www.ebay.com/itm/PD-Power-Designs-2005A-Benchtop-Precision-Power-Source-0-20VDC-0-500MA/274380272361

Purchased, thanks for the tip! Should be a good repair project.

[bitseeker]

Returned the Heathkit IG-18 sine / square wave generator to the owner this morning. I wanted to show him the sine wave output amplitude as related to the Int. / Ext. 600 ohm termination - I asked if I could use his scope. He said yea sure but it hasn't been on in years. I was able to use it but the controls were very dirty, as was the whole unit. Really filthy.

So, were you able to demo the generator with your own scope?

I asked him, if the scope worked well, would he use it? He said he would. So now, I have another project - restoring a Kikusui 20 MHz scope to full operation. I think it just needs a little TLC, no - a lot. Check the pics. One of the dirtiest scopes I've seen in a long while. Right now the cover is off and its airing-out on the front porch. 

Excellent! You're the first person I've met that is in possession of a Kikusui scope that's at least related to my COS-5021. I've had it for almost 30 years. I stopped using it over a decade ago when the focus drifted past the limit of the adjustment pot. I tried to find a manual for it last year, but didn't find an available one. So, back it went in the closet until I feel like embarking on a lonely restoration project. He doesn't happen to have the manual for his, does he?

[med6753]

Excellent! You're the first person I've met that is in possession of a Kikusui scope that's at least related to my COS-5021. I've had it for almost 30 years. I stopped using it over a decade ago when the focus drifted past the limit of the adjustment pot. I tried to find a manual for it last year, but didn't find an available one. So, back it went in the closet until I feel like embarking on a lonely restoration project. He doesn't happen to have the manual for his, does he?

That focus problem should be a simple fix and you don't even need a manual. In the focus voltage divider circuit (which includes the pot itself) you will find several high value (meg ohm) resistors. Generally 2.2M or 4.7M. One of them has drifted way up or the usual fault is they go open. It should be easy to trace on the circuit board without the need for a schematic.

[xrunner]

So, were you able to demo the generator with your own scope?

I demoed it with the Kikusui at his bench, it just took me a while to get it to respond to the controls. It had been sitting under his computer monitor for years accumulating pipe smoke. That's when I offered to re-condition it. It's very dirty and noisy but I think with luck it will work OK.

Excellent! You're the first person I've met that is in possession of a Kikusui scope that's at least related to my COS-5021. I've had it for almost 30 years. I stopped using it over a decade ago when the focus drifted past the limit of the adjustment pot. I tried to find a manual for it last year, but didn't find an available one. So, back it went in the closet until I feel like embarking on a lonely restoration project. He doesn't happen to have the manual for his, does he?

The user manual is attached. I got the user manual from Kikusui's web site (yes it's still there!). However; there is no service manual or schematic there. I hope I will not need one. 

[bitseeker]

I start a resolution, asking for a refund as I figure after 6 weeks I've been reasonably patient already; the vendor replies crying COVID delays and asking that I wait another 2 weeks. Since I already have a resolution process open, do I give the guy a break, or is 3 weeks late just unreasonable, even with COVID delays...?

I'm still waiting for my orders from China that were placed in March.

It's probably coming next month, I'm receiving February at the moment 

Interesting. Thanks for the happy thoughts.