Test Equipment Anonymous (TEA) group therapy thread

[Brumby]

I need advice from a professional TEA therapy coach to find a good excuse to not to buy this:

Ah ... Hmmm ...  ...  ...  Nope.  I've got nothing.

This is not the place to be talked out of buying anything (outside of major technical roadblocks you could face).

[McBryce]

I need advice from a professional TEA therapy coach to find a good excuse to not to buy this:

(Attachment Link)

I know I don't have space for it, and I don't need it, and I can buy a more modern one for the same price... but... but...

link to the publication: https://www.ricardo.ch/de/a/soldering-microscope-1213926126/

Let's look at this rationally and logically:

A) You don't need it.
B) You don't have the space.
C) Modern devices would give you much better results.
D) It may get damaged during delivery.

Conclusion... Yeah, buy it!

McBryce.

[Brumby]

Excellent precis of the TEA logic process.   

[Ice-Tea]

Keithley 580. Didn't power up.



Seems the battery pack was dragging the power supplies down. Starts fine after unplugging it. Now let's see if it works well.

[salvagedcircuitry]

I was googling for an 'insides' picture of this scope and ended up with a tweet from this "salvaged circuitry" dude 

Anyhow, the series of scopes before this had capacitor plague issues on the ATX mobos. If it's that, it would be an easy fix. Do you have any info about failure mode?

Hahaha. I purchased my last dso80k from keysight used. I at least knew that 3 of 4 channels tested fine.
This unit I have no idea. Quite the gamble. 

[BU508A]

I would take at least 3, up to 10 even to make it worthwhile....

When I have them, I'll let you know. We can figure out then the details.

Got today the ICs. 3x RCA and 7x Philips - all in all 19 Euro.
Checked delivery to .jp via DHL as XS parcel: 11 Euro without tracking.
Overall costs 30 Euro. Send me PM if this is okay for you.

[Vince]

We had a development board based on a 8XC552 I remember a big PLCC package.

You mean something like this?
Edit: Copyright 1993 by HiTech Equipment Corp. A SBC552 Revision D.

Oh, just saw your edit after I had already replied, and figured there might be a misunderstanding here....
When I said "This is it" (before you edited your message), I referred to the PLCCC 552 chip itself, not the board as a whole.

The board we had I have no idea who made it. I remember the 8051 based board we had, we called the " CEIBO "board because I think that was the company who made it.
However our 552 based board didn't have a nickname... I have no idea who made it !
I remember the forma factor and looks of it. Double side, tinned traces and no solder mask or silk screen. was rectangular, some standard Euro size PCB I guess, maybe 160x100mm or something not far off.
I remember my teacher gave me a bare PCB and bough me the components so I can make my own board !.... I don't remember actually building it though, for some strange reason...
The fact that we had the files to make copy of the PCB... maybe meant that my teacher(s) designed them themselves ! I remember one of our two electronics teachers was super old, geeky and heavy into 8 bit CPU stuff, (he was the one teaching us all the CPU / embedded stuff) he could write Z80 MACHINE code, not assembler... machine code.  I remember him telling us (that would have been in 1996 or 1997), how GLAD we should be to learn on that fancy 8051 MCU, because it was so easy to use and luxurious compared to the Z80. I remember he said as an example, that "compare and jump" test instructions were a pain with Z80 as the execution time of the instructions  was different depending on the result of the test, where as with the 8051 the exec time was consistent, you could rely on it to make your loop calculations.


As for " HiTech " that rang a bell ! in 2000 when I was doing my industrial placement in the UK, developing some code for a PIC MCU.... I seem to remember the boss had me code in C language using an MS-DOS version of C compiler which I am pretty sure was called "HiTech" as well ?!

[DC1MC]

The most impeccable Tek 577 one I've found, too bad that I can't get it, but let's enjoy it together:

https://www.ebay-kleinanzeigen.de/s-anzeige/tektronix-577-curve-tracer-kennlinienschreiber/2257917353-168-6326

[Peter_O]

The most impeccable Tek 577 one I've found, too bad that I can't get it, but let's enjoy it together:

https://www.ebay-kleinanzeigen.de/s-anzeige/tektronix-577-curve-tracer-kennlinienschreiber/2257917353-168-6326

Yea. Hamburg Munich is a trip too far and expensive.   

[m k]

It explains why you mentioned the L1436 connector, they were still made back in 2009 and are the most fragile inside, tiny screws that can easily break off.

I even found few new ones, but from Australia so shipping will be more than nominal.
Search continues.

The PSU then.

Not 600V, not even double 300V.
Two voltages yes, but for separated circuits.

Scope probe is 10x so ripple is few volts peak to peak.
It's also crackling/buzzing, must be 50Hz.
Should I see more glow?

[RoadDog]

After going back and forth with the seller they finally accepted my off in this Fluke 845

No clue if it works or not. Picked it up cheap. Should arrive Monday and I’ll report back what condition it’s in.

My first piece of metrology grade gear.

[Neomys Sapiens]

So I ordered 5kg of ammonium perchlorate ...

[Neomys Sapiens]

At least the pedigree of the preamplifier becomes clearer now (see attached document).
Bandwidth-wise not exactly what I had hoped for when I saw it labeled as having a 50Ohm output, but I'm sure that it will be handy for something one day...for 1.50€ that was a no-brainer for sure.

One thing is becoming a bit of a serial annoyance: a lot of instruments and accessories that I have aquired in the last time need special DIN(diode)-type connectors. Some with Renk lock, some with threaded lock, some (Like the UDL44) even the most basic variant without a lock. Not exactly an area where I held extensive stocks until now.

[TERRA Operative]

Booo. Mouser messed up the DIN41612 connectors I ordered for my AFG5101 adapters.... Just sent an email to see what they say, so I'll hold off on passing judgement for now. Shit happens, life goes on.

I was planning on running through the adjustment procedure after replacing the single turn trimpots with multiturn types, but that will have to wait as I need the extender cables to do it.
(I had to redesign the ones I made previously as the original design of one was in the way of some trimpots).


But I did pick up a cheap Lenovo Thinkpad X270 laptop to dual boot Windows10 and Linux Mint. Will be used for hacking away at older test gear. I chose the smaller size laptop so it takes less space on the desk, but it still has the 1080p screen so nice for the eyes.

[Robert763]

At least the pedigree of the preamplifier becomes clearer now (see attached document).
Bandwidth-wise not exactly what I had hoped for when I saw it labeled as having a 50Ohm output, but I'm sure that it will be handy for something one day...for 1.50€ that was a no-brainer for sure.

One thing is becoming a bit of a serial annoyance: a lot of instruments and accessories that I have aquired in the last time need special DIN(diode)-type connectors. Some with Renk lock, some with threaded lock, some (Like the UDL44) even the most basic variant without a lock. Not exactly an area where I held extensive stocks until now.

I thought so, a photodiode amplifier. The scientists who buy these along with lock-in amplifiers and things like patch clamps and potentiostats seem happy to pay a fortune for basic electronics in a easy to use package. I can see why they moved into audiophoolery. The amplifier could make a front end for a source / measure set-up or high resistance meter.
Years ago a company I worked for bought the rights to a scanning fluorescence microscope that had clearly been designed by scientists. It had two similar amplifiers that cost several hundred pounds each but were set to fixed gain. As part of the productionisation I designed a new dual channel preamp. I didn't look in the existing ones. I picked a high perfrmance op-amp for the front end I can't remember the paet number but it cost about £20. the rest were OP27s. It lowered the BOM cost by over £1000 and improved the performance by 6 or 7 dB. I them looped in the commercial unit and was shocked to find it just used OP27s throughout. Even the PCB layout was poor.

Robert.

[Brumby]

I them looped in the commercial unit and was shocked to find it just used OP27s throughout. Even the PCB layout was poor.

"Professional" - just means they get paid to do the job.  Doesn't mean they are any good at it.

[Vince]

It's 23H15 here, I am just back home. I just drove 900kms today, to get to Bordeaux. I came back with a car full of vintage stuff, the rear suspension was sitting rather uncomfortably low... luckily it was all motorway so handling performance and braking were not too much of a concern, my old Safrane performed much better than I thought. I am so tired and knackered that unloading the car will have to wait 'till tomorrow. Hopefully no scum bag will break into the car during the night. Hopefully during my sleep I will dream of HOW I will manage to store all that t stuff inside my cluster fuck of a tiny house ! 

Be prepared for lots of pics and TE goodness tomorrow. 

Good night.... 

[Vince]

I them looped in the commercial unit and was shocked to find it just used OP27s throughout. Even the PCB layout was poor.

"Professional" - just means they get paid to do the job.  Doesn't mean they are any good at it.

Yes indeed ! I came to that same conclusion after having my house built by "professionals !!! "     

The experience has been so traumatizing that I now can't get myself to pay any professional any amount no matter how small, to do any sort of job no matter how small, simple and low tech.
The only thing you can have 100% trust about professionals, is that they will take your money, and can legally get away with it, you are screwed. So all you can do is anticipate the problem and NOT give any of these crooks any of your money to begin with.

[factory]

I bought back the HP 5090A from storage, it behaves much the same, loop volts works and a lack of signal, or maybe it's the Philips RF gen that isn't working properly. 



The power indicator is dead, 100Kc output functions OK, but 10Mc output is faulty, after running it for a while, I noticed the mains transformer seemed excessively hot. Checking later the mains power consumption was around 27W, manual states 8W. 

Later I disconnected the secondary from the PSU board, with no load the power only dropped to 21W. 
Think this one is terminal, one secondary winding measured at 39.6V, the other at 22V (must have shorted turns), need to find another one to restore.





Robert do you still have the 5090A & 5090B, would you be interested in selling them to me?

David

[m k]

DIN41612 or Eurocard connectors! Cheap and easy to get from the usual places. Sweeeeet.

So, making extender cables to allow me to move the outer cards out of the way to let me tweak the adjustments on the inner cards as required in the adjustment procedure will now be a cinch.

Next time you visit one of those usual places be a sport and ask if they happen to have some wider end connectors of EDAC 379-series.
I'd like to have some, but that's actually just some.

There are a few places with card edge connectors around Akihabara. Do you have any specifics of what you are looking for?

The project is few extenders for Fluke 8505A.

Problem is that spacing is .150" and connector alternatives are not many.
EDAC 379 is one that is at least still in production, I think, but nobody seems to be storing them.
So bulk amounts are available but I don't want them that much.

Used widths are 40 and 40 + over 20, ends are a bit uncertain.
So 40(2x20) is pretty ideal.
Pin lengths and connector end styles are not so important, some mechanical adjustments are expected.

Mouser have some so I bought few.

[factory]

It explains why you mentioned the L1436 connector, they were still made back in 2009 and are the most fragile inside, tiny screws that can easily break off.

I even found few new ones, but from Australia so shipping will be more than nominal.
Search continues.

...snip...

I have one new left & a couple of used ones. Do you want me to find out the costs to send the new one?

David

[factory]

Thought I would join Vince & add a Rochar DVM to my collection, this one appeared in the UK a few weeks back, advertised as Nick-sea & cull-ock, typical of sellers here.  Sadly I wasn't lucky enough to get a manual with it.



It's now waiting a roundtuit, next to the HP 132A. 

David

[Vince]

WOW !!!!

Rochar bits of kits are rare enough over here in their homeland, so finding one abroad, well done ! 

It's looks super cool and in very good nick as well  ! 

Too bad about the manual.. I googled and failed to find one   
Looks like I got real lucky to find one for my Rochar DVM and Counter.

Please do post on here about it, I want to know all about your progress on it !   

I hope it will work, or be easy to fix, so that you don't need a manual...


There is always " Electropuce " as usual, who sells vintage TE and has lots of manuals.
He saved my bacon once, he had a manual for one of my Nixie Metrix counters. He is not cheap though,he sold it for 40 Euros (shipped), but I got my money's worse. Original paper manual, and extremely thick/comprehensive, I was in heaven.

I see that he has a Rochar A.1466 for sale :

https://electropuces.pagesperso-orange.fr/index.htm

, so maybe he has a manual for it too... though it's not listed on his website so maybe he doesn't have it 
Worth a try anyway. Tell me if you want me to contact him about that.

His example has a different plugin than yours, an interesting one I find : can do 4 wire ohms measurements !
First time I hear about an old Neeksee DVM that can do that ! Pretty neat ! 


Google found me this : some web site that shows a PDF document which if you search it, says it has a manual for that DVM !   

https://docplayer.fr/16668023-Sr209-6-field-intensity-meter-manuel-technique-a-128-cs201-generateur-synthetiseur-manuel-d-instruction-f-69.html


But at 77 Euros, for photocopies, it's a bit dear.
Also this document may well be completely obsolete by now. At the top of it there is a company logo I recognize : " ICP électronique ".
This rings a bell. I think it's a French electronics retailer that my retired EE friend told me about. So I guess I could try to contact them and see if they still have that manual in 2022.

[Zoli]

Blast from the past

Some time ago I've decided to build two 50Ω termination for my scope inputs. The best fit looked the Pomona 2391; checked Digikey/Mouser - past summer was ~$46, now ~$76 
Off the fleabay I go, after a little negotiation got two Pomona's delivered for the price of one@Digikey
Merchandise arrives, open it up: get hit in the face with a typical 60/70's style logo on two unopened Pomona 2391. On the label, in the right bottom, is the date code: 326.
Back to fleabay, the seller has a picture of an inventory sheet from August/September 1976. Week 32:early August, so everything checks out: those two boxes had been manufactured in week 32 of 1976(does anybody remember that summer Olympics? I do).
Now about the project: since is built mostly for one specific purpose(checking SMPS noise; general use is OK, too up to 30MHz), I've added two more parts: DC blocking capacitor(to keep the magic smoke within the 4X200Ω resistors ) and input/bleeding resistor(who wants a 10µF capacitor charged to 100V in the drawer? ).
Added labels on the bottom; if I ever forget, what's in the box, the schematics is on the bottom.
Stray capacitance of the box with the 10µF/100V installed is around 15pF.
The scope screenshot is what you can expect from the FY-6800.
Overall, I'm happy with the end results; what took me by surprise was the fact that the same product is available unchanged(almost; current version has 4 solderable screws/connector) for nearly 5 decades(proven; wouldn't surprise me if the design originated in the early 50's).

[TERRA Operative]

Nice.

I've been making my own versions using these enclosures from ebay with some BNC's at each end.
Just enough space for a couple passives or a small PCB inside, but longer ones are available if needed.

https://www.ebay.com/sch/i.html?_nkw=Black+Aluminum+Enclosure+40x25x25mm