Test Equipment Anonymous (TEA) group therapy thread

[gnif]

I have been with this thread since page 3. And since then I have contributed literally hundreds of hours of my time devoted to test equipment tear downs, repairs, and restorations. As well as hundreds of accompanying photos. And yep, some off content stuff too. But to suddenly be branded a "bad actor" I find absolutely insulting and unwarranted.

I promise not to let the door hit on the arse on the way out.

Sorry if you feel offended by this as it was not intended to offend. Please note that my background is in network security and as such the term "bad actor" is generally referring to someone trying to break a system. I am not trying to coin anyone here as a criminal or a bad person. All I am stating is that it's the minority that do not agree that are causing the problem here (by continuing to post OT), but at the end of the day, these are the rules and no amount of arguing will change this.

[Zenith]

So you admit this is an issue, yet you are not willing to let the moderators try to prevent it derailing so far that the forum devolves into just a mess of off-topic garbage?

The fact I find something occasionally irritating, does not necessarily mean I  think it's a great idea for the police to get heavy with whoever is doing it, especially when it's been tolerated for ages. Some things you have to put up with.

Where do we draw the line?

That's a hard one. Forums have been killed by over enthusiastic moderation before now.

[gnif]

The fact I find something occasionally irritating, does not necessarily mean I  think it's a great idea for the police to get heavy with whoever is doing it, especially when it's been tolerated for ages. Some things you have to put up with.

You state it like we tolerated it.... we did not. Again, how can you expect us to moderate every single post made every single day? We came, we saw the issue and we dealt with it... toleration would have been to make a comment stating it was OK here, just like we have with regards to not being required to post TE stuff here.

That's a hard one. Forums have been killed by over enthusiastic moderation before now.

Yes it is, and yes they have, but on the flip side, forums have been killed by under-moderation also.

[25 CPS]

I'm at work drinking some coffee on the last leg of an overnight shift.  Some preventative maintenance plus one fault call, so it's been a pretty quiet night.  Before I forget, I'm a senior blah blah blah technologist that was hired out of electronics school to do electronics and IT work, so work is very much on topic.

Anyways, during the downtime, I was checking a bunch of Keysight bench meter data sheets and manuals specifically for math functions since there is a nice bench DMM available not too too far from me for sale.  It would move up one of the bench DMMs at home to the modern era but it doesn't really add much functionality over the existing ones and it's a bit of money so I'm on the fence.  The feature that would've sold me was a power computation where you could enter a load resistance and have it measure a voltage and then calculate and display the power in watts on the display.  E.g. power developed into a 4 or 8 ohm dummy load.  The other math function I was hoping for was to be able to take a voltage measurement off an external current shunt and have it compute and display an amperage.  The meter under consideration for purchase and all the other similar models I looked at to see if this functionality showed up in the HP/Agilent/Keysight lines along the years somewhere but hasn't appeared in any of the meters whose documents I checked.  The absence of a power in watts kind of surprises me given how many of them can do a dBm calculation so it isn't for lack of ability to do it on the microprocessors that have been used for everything from at least the 34401A on up.

What I was not expecting to see when I went to post about it was a trip down memory lane to my first electronics job where the owner of the business also presided over a couple of non-profit volunteer groups and everything bled together and one of his favourite phrases was to tell people "You should've come to me first to get the correct opinion" combined with Trudeau making smarmy statements about "fringe minority with unacceptable views" if you don't subscribe to the groupthink line and verse without question.  Don't think for yourself, do as you are told, stand in the corner, nod yes, don't speak, and know your place in the world.  And I am beginning to seriously question whether that's here.

[gnif]

Lets move the moderation discussion to a separate thread please:
https://www.eevblog.com/forum/chat/discussing-the-usage-of-the-tea-thread/msg4375912/#msg4375912

Let this thread return to electronics related posts, not moderation discussion.

[TERRA Operative]

This thread is useless without pics videos:



Sorry for my shaky hands...

What are those FDD emulators like to use?
If I want to transfer files from say my Tek TDS784D scope, is it seamless on the scope side? How do I access the files on my PC? Is it just files in folders as usual for Windows?
And finally, how fast is it compared to a real floppy disk for file transfers?

I have been thinking of getting some for my scopes and HP Semiconductor parameter analyzer etc.. It would be perfect if it was just a matter of dragging and dropping files to and from the USB stick on my PC.

[factory]

...
Crazy how when you put something aside to work on it 'later' just how quickly 'later' can turn into years.  I've done the same.  Sadly, those decoders are like hen's teeth.

-Pat

Nobody tried to build a discrete replacement? A quick look in the service manual shows that is a simple BCD-to-10line decoder, with high voltage outputs; it should be pretty straightforward way to build them, and look like there's room to mount the boards vertically in the place of the old IC's.

I was actually thinking about it today.  May try to cobble something together, either to fit a 74141 (also nearing hens-teeth status) or the Russian equivalent (can’t recall the number off the top of my head), or perhaps a low voltage BCD to 10 line decoder with switching transistors, though that’d be much bulkier.

-Pat

Do SMD; CD4028B(SOIC-16) as decoder, PBHV8050SA(SOT-23) as switchers, 0603 R&C, and install it something like below. If you need some help, I can quickly draw something. PM if interested.

I'll get OrCAD fired up and play around with a design.

-Pat

The HP 1820-0092 decoder/drive IC uses negative logic, I believe they used the BCD 10 to 15 (no output) for blanking in some counters.



I started making a prototype based on a 74141, with a surface mount 7400 (connected as inverters) stuck on the back, unfortunately ...OT would get deleted... got in the way & it never got finished, probably lost my notes by now. 

The idea was to eventually use some miniature USSR made 74141 clones I bought & the 7400 on a small surface mount board, leadframe connections would be preferable to pin headers, to allow easier removal from the HP board if it were to fail.
Unfortunately trying to make a package layout in KiCad, for the miniature 74141 clone is a problem for me, still need to properly learn KiCad. Thinking about it, it might be difficult to get the datasheet for the USSR made miniature decoder/driver IC now, don't want to get my PC hacked/attacked for looking at .ru sites (this was mentioned on another forum relating to web SDR).

Also might need several different board designs, depending on the space available, for example the 5221 has lots of space above the IC, but limited clearance to push the board into the plastic frame.



Will try an add some pictures of the bits later, can't find any on the PC.

David

[gnif]

unfortunately ...OT would get deleted... got in the way & it never got finished

Please don't think we are this extreme, your post is wholly electronics related and I thank you for it, and you're welcome to mention such things inside such posts, however if a discussion on such an off topic thing erupts as a result, it (the discussion) needs to stop.

[Zoli]

...
Crazy how when you put something aside to work on it 'later' just how quickly 'later' can turn into years.  I've done the same.  Sadly, those decoders are like hen's teeth.

-Pat

Nobody tried to build a discrete replacement? A quick look in the service manual shows that is a simple BCD-to-10line decoder, with high voltage outputs; it should be pretty straightforward way to build them, and look like there's room to mount the boards vertically in the place of the old IC's.

Yup. That’s about it. Use a 74LS42 and some MPSA42’s.

74xx42 and 74xx145 are active low(0x00==0b1111111110); no-go in this case. CD4028 is active high(0x00==0b0000000001), so is able to drive BJT's directly to give you the proper active low outputs on the HV side.
@factory: the replacement board can be socketed; it will have better cooling(vertical airflow) and fraction of the original's current consumption(practically, all the current goes to drive one transistor's base; PBHV8050SA has an h_fE of 150@1mA, so 100µA drive is more then enough).
Personally, I would build something like below:

[dl6lr]

This thread is useless without pics videos:



Sorry for my shaky hands...

What are those FDD emulators like to use?
If I want to transfer files from say my Tek TDS784D scope, is it seamless on the scope side? How do I access the files on my PC? Is it just files in folders as usual for Windows?
And finally, how fast is it compared to a real floppy disk for file transfers?

I have been thinking of getting some for my scopes and HP Semiconductor parameter analyzer etc.. It would be perfect if it was just a matter of dragging and dropping files to and from the USB stick on my PC.

It depends. All "discs" are stored as image files on the USB stick. If the drive to be replaced is a standard PC drive and the file system is standard DOS FAT, you can just use a PC-Software from HCX2001 to access those images. I never used the factory software so I don't know anything how it is accessed, always used to replace drives in machines that can't be replaced with real drives.
If it is any other file system layout you have to find a software that is able to process the file system on the PC. I.e. some machines use CP/M file system, there are cpmtools to extract files. And regarding speed: It is limited through the disc drive interface, so it is not faster than a normal disc (a little bit as seek times and motor on times are eliminated).
The other instrument I replaced a 5.25" drive with was a Gould LA K105, where the drive was bad, too. It uses a sort of CP/M86, but with a strange file system variant, you cannot use cpmtools to access files from it. But I use it mostly to run software from it that came on optional disks, like disassemblers for the LA. So there is no use case to access those files from another PC.

[TERRA Operative]

Ah, so it doesn't appear as a standard set of folders in a normal USB thumb drive on a PC even if using a standard Windows disk format?
Hmm, having to use a bit of software to access files makes it no easier for me than just using the (currently working) floppy drive.

Thanks for the info!

[bitseeker]

Greetings fellow Test Equipment Addicts,

Back in January of 2017, when Test Equipment Anonymous began as a combination of personal reflection on my own joy of test gear, the admission by several like-minded folks of their symptoms of Gear Acquisition Syndrome, and a somewhat tongue-in-cheek parallel to more serious organizations whose names end in "Anonymous", I of course couldn't foresee just how many others were like us.

The discussion of our ailments began with a 12-step program, but not wanting to derail the thread in which it was first posted, a new thread was started for TEA. Over the next five years, the TEA thread and the TEA Glossary grew along with its community of like-minded, self-governing individuals who found camaraderie in more things than just test equipment.

Today, the TEA thread contains 20% of the posts of the Test Equipment forum. It dwarfs the size and views of any other thread on EEVblog. Clearly, the TEA community needs more than a single thread to accommodate the diversity of its members and the richness of the discussions that we have always had.

Thus, TEA has a new home at https://groups.io/g/tea and TEA Time live chat on Saturdays at 21:00 UTC will continue as before.

Thank you, Dave Jones, for your ongoing commitment to bringing electronics to the masses and for putting up with our TEA nuttiness over the years.

I look forward to seeing you all at the new TEA House.

bitseeker
TEA founder and fellow addict

[gnif]

Greetings fellow Test Equipment Addicts,

Back in January of 2017, when Test Equipment Anonymous began as a combination of personal reflection on my own joy of test gear, the admission by several like-minded folks of their symptoms of Gear Acquisition Syndrome, and a somewhat tongue-in-cheek parallel to more serious organizations whose names end in "Anonymous", I of course couldn't foresee just how many others were like us.

The discussion of our ailments began with a 12-step program, but not wanting to derail the thread in which it was first posted, a new thread was started for TEA. Over the next five years, the TEA thread and the TEA Glossary grew along with its community of like-minded, self-governing individuals who found camaraderie in more things than just test equipment.

Today, the TEA thread contains 20% of the posts of the Test Equipment forum. It dwarfs the size and views of any other thread on EEVblog. Clearly, the TEA community needs more than a single thread to accommodate the diversity of its members and the richness of the discussions that we have always had.

Thus, TEA has a new home at https://groups.io/g/tea and TEA Time live chat on Saturdays at 21:00 UTC will continue as before.

Thank you, Dave Jones, for your ongoing commitment to bringing electronics to the masses and for putting up with our TEA nuttiness over the years.

I look forward to seeing you all at the new TEA House.

bitseeker
TEA founder and fellow addict

To be clear, this thread will still continue to exist here for those that still wish to use and participate here.

[Robert763]

...
Crazy how when you put something aside to work on it 'later' just how quickly 'later' can turn into years.  I've done the same.  Sadly, those decoders are like hen's teeth.

-Pat

Nobody tried to build a discrete replacement? A quick look in the service manual shows that is a simple BCD-to-10line decoder, with high voltage outputs; it should be pretty straightforward way to build them, and look like there's room to mount the boards vertically in the place of the old IC's.

Yup. That’s about it. Use a 74LS42 and some MPSA42’s.

74xx42 and 74xx145 are active low(0x00==0b1111111110); no-go in this case. CD4028 is active high(0x00==0b0000000001), so is able to drive BJT's directly to give you the proper active low outputs on the HV side.
@factory: the replacement board can be socketed; it will have better cooling(vertical airflow) and fraction of the original's current consumption(practically, all the current goes to drive one transistor's base; PBHV8050SA has an h_fE of 150@1mA, so 100µA drive is more then enough).
Personally, I would build something like below:

You will need inverters on the input for that to work. The original HP part is negative logic.  That could iclude level shifting if required.

[Cubdriver]

...
Crazy how when you put something aside to work on it 'later' just how quickly 'later' can turn into years.  I've done the same.  Sadly, those decoders are like hen's teeth.

-Pat

Nobody tried to build a discrete replacement? A quick look in the service manual shows that is a simple BCD-to-10line decoder, with high voltage outputs; it should be pretty straightforward way to build them, and look like there's room to mount the boards vertically in the place of the old IC's.

Yup. That’s about it. Use a 74LS42 and some MPSA42’s.

74xx42 and 74xx145 are active low(0x00==0b1111111110); no-go in this case. CD4028 is active high(0x00==0b0000000001), so is able to drive BJT's directly to give you the proper active low outputs on the HV side.
@factory: the replacement board can be socketed; it will have better cooling(vertical airflow) and fraction of the original's current consumption(practically, all the current goes to drive one transistor's base; PBHV8050SA has an h_fE of 150@1mA, so 100µA drive is more then enough).
Personally, I would build something like below:

You will need inverters on the input for that to work. The original HP part is negative logic.  That could iclude level shifting if required.

I plan to open one of my counters up and do some probing in the next few days.  It'd be worthwhile to cobble together a sub for the 1820-0116 and -0119 as well.  I might have old DIP versions of the 74xx and CDxx logic chips somewhere here in my stash to permit breadboarding for proof-of-concept.

-Pat

[Zoli]

...
Crazy how when you put something aside to work on it 'later' just how quickly 'later' can turn into years.  I've done the same.  Sadly, those decoders are like hen's teeth.

-Pat

Nobody tried to build a discrete replacement? A quick look in the service manual shows that is a simple BCD-to-10line decoder, with high voltage outputs; it should be pretty straightforward way to build them, and look like there's room to mount the boards vertically in the place of the old IC's.

Yup. That’s about it. Use a 74LS42 and some MPSA42’s.

74xx42 and 74xx145 are active low(0x00==0b1111111110); no-go in this case. CD4028 is active high(0x00==0b0000000001), so is able to drive BJT's directly to give you the proper active low outputs on the HV side.
@factory: the replacement board can be socketed; it will have better cooling(vertical airflow) and fraction of the original's current consumption(practically, all the current goes to drive one transistor's base; PBHV8050SA has an h_fE of 150@1mA, so 100µA drive is more then enough).
Personally, I would build something like below:

You will need inverters on the input for that to work. The original HP part is negative logic.  That could iclude level shifting if required.

I plan to open one of my counters up and do some probing in the next few days.  It'd be worthwhile to cobble together a sub for the 1820-0116 and -0119 as well.  I might have old DIP versions of the 74xx and CDxx logic chips somewhere here in my stash to permit breadboarding for proof-of-concept.

-Pat

Here's the updated POC drawing, thanks to Robert. Breadboarding Nixies sounds a little dangerous, personally I would try with LED's first.

[AVGresponding]

Good grief, I go to work for a few hours and when I come back I find things have gone thermo-nuclear... whatever happened to moderation (with a small "m") in all things?   

Currently waiting for some Fluke Suregrip croc clips to turn up that I got for Not Very Much. In the mean time I have to be happy with a couple of Metcal SCV-CH50 tips for Next To Nothing (have 4 NIB now, should last me until the apocalypse) that arrived yesterday and a Starrett outside micrometer, 0-25mm, that came today, for A Quite Reasonable Price.

Hopefully things calm down around here and we can get back to mostly TE posts with a sprinkling of off-topic, so the Moderators (with a capital "M") can leave us alone.

[TERRA Operative]

Some people took exception to being told to keep things on topic. That's all it really boils down to.

[m k]

What you need, a vanilla copy of the original disk?
That will be easy if you have the disk.

Yes, but I don't have any original discs...

But: I am an idiot. After having disassembled a part of the 8088 based FDC controller ROM with the formatting routine, I found the cause why it was refusing to accept the FlashFloppy Gotek emulation as a real disc. And of course everything has already been presented to me, I just didn't catch it:

Cylinder 78 head 1 is formatted using a track id of 150 in the sector headers, not the usual 78. Of course this information was already hidden in the Teledisk image. And I read through the dump but didn't find it as the track header inside the dump was using the correct cylinder numbers, but the sector headers did not (In fact there is no such thing as a track header with track ids on the disc, the track preamble consists of 80 bytes 0x4E, 12 bytes 0x00, 3 bytes 0xC2 with missing clock transistion between bits 3 and 4,  1 byte 0xFC index mark, 50 bytes 0x4E). All other used tracks have the correct track id in the sector headers, even the cylinder 79 using different sector ids. And the raw images cannot handle such track ids, as the sector headers are generated on the fly by FlashFloppy, using the cylinder that is stepped to.
After some discussion with Keir Fraser he suggested to use HFE format instead. And that works like a charm. I created an empty image and formatted it in the 4952A. And then converting the Teledisk format to HFE (with patching the data rate as it was taken with a PC drive) immediately worked too.

BTW: The HP firmware programmer must have smoked something silly. They coded a simple negation for the head select as follows (CL contains 0x00 or 0x01):

Code: [Select]

       f000:9279 f6 c1 ff        TEST       CL,0xff                                         
       f000:927c 74 02           JZ         HEAD0
       f000:927e b1 ff           MOV        CL,0xff                                         
                             HEAD0                                           XREF[1]:     f000:927c(j) 
       f000:9280 fe c1           INC        CL


Can you now duplicate program disks?

Maybe the code had multi head HDD something earlier.

[Vince]

Wow, not yet another forum split ! I thought that was '90s era.... 

I once used to uise Groups.io, for it hosts TekScopes.... but IIRC when I stopped using it 5 years ago it was mostly because the user interface and features were painful, espeically working with images. found it orders of magnitude more convenient on EEVBlog which is why I started posting my TE repairs there, especially once I realized many of the old beard helping me on TekScope... were also subscribed to EEVblog and were helping me there as well !

I don't fancy going back to Groups. io because of that... also, it will make it impossible for newcomers, fresh blood, to find us, or even know of our existence, and soon we will be going circles.

Also, the present thread has a tremendous value to me at least, because it archives allllll the work I did to restore my old junk. Tons of pics, tons of loud thinking and trouble-shooting...

One would need to be able to import all the past TEA messages and pics, into Groups.io.
 Bitseeker did such a fantastic job or building a TEA "contents table" of POI on the first page, it's really extremely valuable. SO we would need to modify alll the links it contains, to point to groups.io messags links instead..... lot of work (I guess the IT wizards here could automate that  maybe ?)

If it's really a matter of life or death, yes I would move to groups.io (I just subscribed there BTW).

HOWEVER, it would be SO MUCH MORE PRACTICAL if we stayed here instead !

SOLUTION : easy.... to me ?  I do'nt know.... to me, seems that the problem is that our content has too much OT stuff. So, why not simply do click-click-click, and move the TEA thread into a " random chat /lounge " section of EEVBlog, hence we could post OT stuff to our hearts contents and never have anybody complain about it ?

Now I don't know if there is a "random chat" section on EEVBlog, but most forums do... if not, maybe it would be an opportunity to create one ? 

Then all the people who silently complain/report about OT stuff here, are free to start a new TEA thread of their own, in the proper section of the foruml (here then...), and that's it.... then we can watch their thread and as soon as we see anything OT we wuld report it !!! 

No just kidding....

I say just move this thread to a random chat section, or simply leave the thread here and edit it's titel / description to make it obvious that it's kinda a " TEA oriented chat room ", and create a "proper" TEA thread alongside it, labeled " TEA SERIOUS ", or something...

I am trying to be reasonable and find a middle ground here, please consider my idea ! 

I would rather not have to give up on this thread and move to another IT infrastructure, to be honest. 


EDIT : Also, I am not sure Groups.io has enough formatting options to let AVG and Dragon use colourful text.....
And what about emoticons ?

[gnif]

Wow, not yet another forum split ! I thought that was '90s era.... 

I once used to...

I suggest you post this over on the thread created specifically for posts like this:
https://www.eevblog.com/forum/chat/discussing-the-usage-of-the-tea-thread/

[TERRA Operative]

All we gotta do is keep posting on topic and stick around. The world will still turn and the sun will come up tomorrow.
I like reading your stuff Vince. You have some good adventures. 

That is the last I will say on this stuff, my next post will be about my next TEA thing.

[Specmaster]

Good grief, I go to work for a few hours and when I come back I find things have gone thermo-nuclear... whatever happened to moderation (with a small "m") in all things?   

Currently waiting for some Fluke Suregrip croc clips to turn up that I got for Not Very Much. In the mean time I have to be happy with a couple of Metcal SCV-CH50 tips for Next To Nothing (have 4 NIB now, should last me until the apocalypse) that arrived yesterday and a Starrett outside micrometer, 0-25mm, that came today, for A Quite Reasonable Price.

Hopefully things calm down around here and we can get back to mostly TE posts with a sprinkling of off-topic, so the Moderators (with a capital "M") can leave us alone.

Like you, I've just got back home and came online to post about my new LED displays and talk about an issue I had with one of them and hen I went out I'd had a post deleted, and now it looks like a meteoroid has crashed into the thread and left a huge crater and a mess in its wake. Before I post about my TE today, I think I'd better go back a bit and read the posts to see if I can work out the status quo around here again. 

[gnif]

Good grief, I go to work for a few hours and when I come back I find things have gone thermo-nuclear... whatever happened to moderation (with a small "m") in all things?   

Currently waiting for some Fluke Suregrip croc clips to turn up that I got for Not Very Much. In the mean time I have to be happy with a couple of Metcal SCV-CH50 tips for Next To Nothing (have 4 NIB now, should last me until the apocalypse) that arrived yesterday and a Starrett outside micrometer, 0-25mm, that came today, for A Quite Reasonable Price.

Hopefully things calm down around here and we can get back to mostly TE posts with a sprinkling of off-topic, so the Moderators (with a capital "M") can leave us alone.

Like you, I've just got back home and came online to post about my new LED displays and talk about an issue I had with one of them and hen I went out I'd had a post deleted, and now it looks like a meteoroid has crashed into the thread and left a huge crater and a mess in its wake. Before I post about my TE today, I think I'd better go back a bit and read the posts to see if I can work out the status quo around here again. 

You mean this post?: https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg4375849/#msg4375849

[Specmaster]

Well fuck that for an evening out. TGI Fridays RIP  . Film was, erm, pants. Filler material.

TE related. TM6 simulation complete. Completely understand it now  . There's also one popped up on eBay I might have a stab at. It's still reasonably priced at the moment. It makes it easier to repair something if you have two of them!

Especially if the second one is working, then you have a point of reference to use.