Test Equipment Anonymous (TEA) group therapy thread

[Cerebus]

New (2nd hand) toy just delivered:



A Metcal PCT-100 board preheater.  For scale that board's 100mm x 50mm.

The board is little more than 4 solid copper planes with the odd trace on it, and the preheater will take it up to 135ºC and hold it there.

The Metcal also does a lovely gentle controlled ramp down when you turn it off - I haven't profiled the rampdown because the 34461A is currently busy doing something else but by eye it looks something close to the "no more than 3ºC/second" cooling ramp that every soldering profile I've ever seen seen seems to use.

An 3rd party picture of one without board and other bits cluttering the view:

[AVGresponding]

VARTA battery.

AM going to try dwagon's 7805 trick to constant current discharge the battery, just for fun.

So nice to see that my big box of random salvage semi-conductors might be useful !

Let's see what I can find in there !

Emptied it all on the bench, pulled all the TO220 looking packages I could find, sorted them... hey presto, found no less than 34 78/79 regulators, of which 15 were 7805 ! 
Surely at least one of them must be working....

As I was looking at every TO220 package to find the 78/79, every time I read "IRF" I though to myself  "fuck me, must be a MOSFET and I just killed it just by handling it ". Oh well, you gotta have casualties I guess... 

No that I spent time sorting these regulators, no way i hell I am putting them back in the box ! So will put them in a separate box... I didn't plan on starting to sort my components just now, wanted to leave that 'til the end, but I guess this is the start of it ! So, at least a little bit of it has now been done... 

Let's go wire that up on the breadboard see if that works....

Probably not, unless you've been shuffling your feet around on the carpet building up a charge. Modern power mosfets are generally pretty robust.

[Cerebus]

...One of my past jobs was porting an expert system development tool (i.e. AI), written in FORTRAN on PCs under DOS, to Sun, Apollo, Ngen and RS/6000 workstations.

Oh, you poor poor bastard. We didn't know you were a PTSD case; I'll lay off from now on, you've got good reason to be grumpy. 

mnem
I write my code with a pencil. In spiral notebooks.

That which does not kill you makes you stronger. I can now, metaphorically speaking, reenact the cooler scene from the Great Escape, where Steve McQueen bounces the ball off the wall with his hand, with a cannonball and my testicles. I can, but I choose not to; doing network orchestration in Python (what were they thinking) is the nearest I have come in recent years.

[mansaxel]

Windoze PowerShell. 
I'd put on muh flameproof jammies, but dwagons don't need 'em.

The dragon probably finds himself short of breath when he realises that what he wrote is completely irrelevant to the poll.

.
w
q

[Cerebus]

Got the Agilent 34461A out of hock (it was doing temperature measurements somewhere else) and actually measured the ramp-up and ramp-down of the PCT-100:



The whole X axis is 8 minutes. Switch-on was at time 0. I switched it from heat to cool at the 4 minute mark by which time it had pretty much topped out at 149 ºC. So the left half is the ramp up to maximum, the right half the ramp down from switching 'off' to 4 minutes later. The PCT-100 cut the fan off at 45ºC, which was sometime around the 3 minute mark. Sensor used was a 2 wire Pt-100 platinum RTD sensor in a small (3 x 25mm) steel case.

So, intuition fail - the ramp down is more like 1ºC/second, plenty slow enough for thermal shock to be non existant.

[capt bullshot]

What editor you like the most

• vi
  
• nano
  
• emacs
  

?

joe
nedit

[tggzzz]

What editor you like the most

• vi
  
• nano
  
• emacs
  

?

5-channel paper tape on a 5cps teletype, or edlin, or VAX/VMS edt where you didn't know which word the "delete word" command would delete.

That and vi(le) were probably the source of Smalltalk's "don't mode me in" motto and T-shirt

[THDplusN_bad]

Got the Agilent 34461A out of hock (it was doing temperature measurements somewhere else) and actually measured the ramp-up and ramp-down of the PCT-100:

[..]
The whole X axis is 8 minutes. Switch-on was at time 0. I switched it from heat to cool at the 4 minute mark by which time it had pretty much topped out at 149 ºC. So the left half is the ramp up to maximum, the right half the ramp down from switching 'off' to 4 minutes later. The PCT-100 cut the fan off at 45ºC, which was sometime around the 3 minute mark. Sensor used was a 2 wire Pt-100 platinum RTD sensor in a small (3 x 25mm) steel case.

So, intuition fail - the ramp down is more like 1ºC/second, plenty slow enough for thermal shock to be non existant.

Ok, so I am officially envy-green now  That Metcal pre-heater is coming in at 450€ here in Germany...

On a related note: My trusty PACE PPS-17 "SensaTemp" soldering station from the 90s has shown an error LED last week  The handpiece's heater measured 75 kOhm instead of 8 or 10 Ohms.
So, I have reached into the big, ugly card box with PACE replacement parts and found an unused "SODR-PEN" handpiece. Side note: I suppose that PACE marketing had some pretty wild parties when they decided these product names back then...
Luckily, this handpiece uses the same 21VAC supply and compatible tips. And after some treatment of the cable and most plastic parts with Armor All, I have completed the burn-in procedure and was back in business after a few minutes. 

Cheers,

THDplusN_bad

[Neper]

5-channel paper tape on a 5cps teletype...

Now, that brings back memories. Around 1987, we had a IBM XT286 with Wordstar for word processing and a Siemens T1000 telex machine as some of the texts we produced had to be sent by telex. Since there was no legal way of connecting computer and telex machine and the price of a tape puncher for the computer was in the thousands, everything had to be re-typed on the telex machine.

All that until the day I got hold of an old 8-channel tape puncher without any electronics, just the electromechanical part. A strip of PCB stock was quickly cut to size to reduce it to five channels. A friend built an interface on a piece of veroboard for connecting it to the PC's Centronics port, the Best-of-All-Halves^TM wrote the software and, presto, we had a tape puncher that saved us many hours of work. :-)

[Saskia]

What editor you like the most

• vi
  
• nano
  
• emacs
  

?

ed or sed.

you only use emacs to load vmunix.el

[Saskia]

bought a PACE pcb repair kit for 45 brussels pesos. To check it out for CPU board repair. Still have my Bungard press for eyelet repair, however I need to redo a couple of traces. Which will be a pain in the intestines

[Cerebus]

Ok, so I am officially envy-green now  That Metcal pre-heater is coming in at 450€ here in Germany...

Oh yeah, the new prices are eye watering. I missed one that went for £135 a couple of weeks back (I underbid) and decided to bite the bullet when I saw this one as a buy it now of £180. Tad higher than I'd like to have paid but it looked really clean (and proved to be so) and at least with Metcal you only buy it once. (Whereas anyone who's tempted by the circa £100 China direct preheaters will probably end up buying something else that actually works or doesn't break within a year.) Leastways, that's my excuse for splashing out, and I'm sticking to it.

[Vince]

VARTA battery.

AM going to try dwagon's 7805 trick to constant current discharge the battery, just for fun.

So nice to see that my big box of random salvage semi-conductors might be useful !

Let's see what I can find in there !

Emptied it all on the bench, pulled all the TO220 looking packages I could find, sorted them... hey presto, found no less than 34 78/79 regulators, of which 15 were 7805 ! 
Surely at least one of them must be working....

As I was looking at every TO220 package to find the 78/79, every time I read "IRF" I though to myself  "fuck me, must be a MOSFET and I just killed it just by handling it ". Oh well, you gotta have casualties I guess... 

No that I spent time sorting these regulators, no way i hell I am putting them back in the box ! So will put them in a separate box... I didn't plan on starting to sort my components just now, wanted to leave that 'til the end, but I guess this is the start of it ! So, at least a little bit of it has now been done... 

Let's go wire that up on the breadboard see if that works....

Probably not, unless you've been shuffling your feet around on the carpet building up a charge. Modern power mosfets are generally pretty robust.

Well it's salvaged stuff so it's bound not to be super modern... but, at least I have no carpet here ! 

... and before I handle sensitive stuff and regularly while working on it... I grab the BNC sockets of my scopes to discharge myself to earth... if that makes any sense...

[mnementh]

   VARTA battery.

AM going to try dwagon's 7805 trick to constant current discharge the battery, just for fun.   So nice to see that my big box of random salvage semi-conductors might be useful !  Let's see what I can find in there !

Emptied it all on the bench, pulled all the TO220 looking packages I could find, sorted them... hey presto, found no less than 34 78/79 regulators, of which 15 were 7805 !     Surely at least one of them must be working....

As I was looking at every TO220 package to find the 78/79, every time I read "IRF" I though to myself  "fuck me, must be a MOSFET and I just killed it just by handling it ". Oh well, you gotta have casualties I guess... 

No that I spent time sorting these regulators, no way i hell I am putting them back in the box ! So will put them in a separate box... I didn't plan on starting to sort my components just now, wanted to leave that 'til the end, but I guess this is the start of it ! So, at least a little bit of it has now been done... 

Let's go wire that up on the breadboard see if that works....

Don't get too hung up on organizing your semis. This is all stuff bought back in my Cheap Tunes days; when I worked a flea market route in Florida. Mostly AF amps for old car audio and boom boxes, plus a whole assortment of logic, sensors, and motor drive ICs for 90s-00s vintage VCRs, DVD players and CD decks.

Point being... I have 5 more drawers just like this one, and if I search through them more than once in a month, it's unusual.

And yes, they really are all sorted into those crystal compartment boxes with no ESD protection, and I don't give a fuck. Most of it is silicon; what isn't usually came from the supplier in tinfoil. What little remains that is unprotected CMOS... fuggitt. Let my son figure it out when he inherits this mess. 

And then there's another 10 drawers of salvaged semis and discretes... and a couple 20 gallon totes of "donor PCBs" (pared down from like 20 bins, no lie)... and in my Canada stuff, I emptied 20 more drawers worth of new semis, discretes, SMDs and kits into a 120 gallon tote... and then there's the tools...

mnem
"things" are a trap.

[mnementh]

Windoze PowerShell. 
I'd put on muh flameproof jammies, but dwagons don't need 'em.

The dragon probably finds himself short of breath when he realises that what he wrote is completely irrelevant to the poll.

.
w
q

Nope. I am pointing out how incredibly thankful I am that the closest thing to coding I've had to do in the last decade is a few scripts in PowerShell...

You may now burn me in effigy. 

mnem
or in the corner of the room, if you catch me taking a nap; did I mention dwagons are fireproof...?

[Vince]

   VARTA battery.

AM going to try dwagon's 7805 trick to constant current discharge the battery, just for fun.   So nice to see that my big box of random salvage semi-conductors might be useful !  Let's see what I can find in there !

Emptied it all on the bench, pulled all the TO220 looking packages I could find, sorted them... hey presto, found no less than 34 78/79 regulators, of which 15 were 7805 !     Surely at least one of them must be working....

As I was looking at every TO220 package to find the 78/79, every time I read "IRF" I though to myself  "fuck me, must be a MOSFET and I just killed it just by handling it ". Oh well, you gotta have casualties I guess... 

No that I spent time sorting these regulators, no way i hell I am putting them back in the box ! So will put them in a separate box... I didn't plan on starting to sort my components just now, wanted to leave that 'til the end, but I guess this is the start of it ! So, at least a little bit of it has now been done... 

Let's go wire that up on the breadboard see if that works....

Don't get too hung up on organizing your semis. This is all stuff bought back in my Cheap Tunes days; when I worked a flea market route in Florida. Mostly AF amps for old car audio and boom boxes, plus a whole assortment of logic, sensors, and motor drive ICs for 90s-00s vintage VCRs, DVD players and CD decks.

Point being... I have 5 more drawers just like this one, and if I search through them more than once in a month, it's unusual.

And yes, they really are all sorted into those crystal compartment boxes with no ESD protection, and I don't give a fuck. Most of it is silicon; what isn't usually came from the supplier in tinfoil. What little remains that is unprotected CMOS... fuggitt. Let my son figure it out when he inherits this mess. 

And then there's another 10 drawers of salvaged semis and discretes... and a couple 20 gallon totes of "donor PCBs" (pared down from like 20 bins, no lie)... and in my Canada stuff, I emptied 20 more drawers worth of new semis, discretes, SMDs and kits into a 120 gallon tote... and then there's the tools...

mnem
"things" are a trap.

Oh no I am not too hung up as you say (had to google it...) ... just trying to put some sort of order because as you see right now it's just... unusable as it is, and of course I have 3 times as much coming when I get round, progressively, to dismantly the 4 big boxes full of scrap boards I have here...

So I just want to keep the stuff that reasonable going to be used. power trannies, voltage regulators, op-amps... the kind of generic stuff that when I need one to play with, I don't have to spent 3 hours driving down town and queuing for an hour, to buy from my local electronics shop.
If I want to cobble something together quick, a proof of concept, or something quick and dirty, I want to be able to open a drawer and just pick an op-amp or BJT or MOSFET or voltage regulator or diode, diode bridge, dual-diode...or anything mundane like this. I refuse to waste time and money driving to the shop every time I need something basic like this.

So I need to sort all that stuff, keep the generic stuff that can be used, and throw away the specific stuff that's never going to be used, at least not by me, like chips specific to audio/video stuff in old TV sets or whatever consumer electronics stuff I tore apart.


However I do want to buy some ESD foam to store all that... if just because it makes them easy to see, easy to grap, and put back, and allow for a compact layout. Any space saving measure I can take, I am willing to consider...

This evening rushed to H/W store just before it closed. Bought 3 little plastic drawer units to get me started in sorting my stuff (not just semis.... all the rest as well...) this evening. They have them in lots of different sizes. Picked two different sizes here to get me started.. will see how it goes and probably get more of them tomorrow as I see fit.


QUESTION : I looked on Ebay to order some ESD foam, but realize that there are TWO different densities available ?! Never realize that until now...

Which one do people recommend ?! I am worried that the denser foam might be might make it difficult to insert packages with thin / fragile legs, never mind large DIP chips with lots of such pins ?  On the other hand I am worried that the less dense foam might not have enough "grip" to hold a TO220 package upright . I guess I can order both and see what works best but... if I could avoid wasting money buying stuff that I won't even end up using....

Example of the low / standard density foam :

https://www.ebay.co.uk/itm/152465894162?hash=item237faceb12:g:BOEAAOSwNphcGjfe

.. then the high density stuff :

https://www.ebay.co.uk/itm/264836556151?_trkparms=ispr%3D1&hash=item3da97d2577

[mnementh]

...One of my past jobs was porting an expert system development tool (i.e. AI), written in FORTRAN on PCs under DOS, to Sun, Apollo, Ngen and RS/6000 workstations.

Oh, you poor poor bastard. We didn't know you were a PTSD case; I'll lay off from now on, you've got good reason to be grumpy. 

mnem
I write my code with a pencil. In spiral notebooks.

That which does not kill you makes you stronger. I can now, metaphorically speaking, reenact the cooler scene from the Great Escape, where Steve McQueen bounces the ball off the wall with his hand, with a cannonball and my testicles. I can, but I choose not to; doing network orchestration in Python (what were they thinking) is the nearest I have come in recent years.

mnem
*hands C a ticket to ride*

[Andrew_Debbie]

What editor you like the most

• vi
  
• nano
  
• emacs
  

?

I use vi and nano more or less interchangeably.      - I have to admit that I'm starting to use  sudo gedit  on systems that have a gui.   Just being lazy.

[Andrew_Debbie]

Putting the UNI-T 622A to work. 

[mnementh]

Oh no I am not too hung up as you say (had to google it...) ... just trying to put some sort of order because as you see right now it's just... unusable as it is, and of course I have 3 times as much coming when I get round, progressively, to dismantly the 4 big boxes full of scrap boards I have here...

So I just want to keep the stuff that reasonable going to be used. power trannies, voltage regulators, op-amps... the kind of generic stuff that when I need one to play with, I don't have to spent 3 hours driving down town and queuing for an hour, to buy from my local electronics shop.
If I want to cobble something together quick, a proof of concept, or something quick and dirty, I want to be able to open a drawer and just pick an op-amp or BJT or MOSFET or voltage regulator or diode, diode bridge, dual-diode...or anything mundane like this. I refuse to waste time and money driving to the shop every time I need something basic like this.

So I need to sort all that stuff, keep the generic stuff that can be used, and throw away the specific stuff that's never going to be used, at least not by me, like chips specific to audio/video stuff in old TV sets or whatever consumer electronics stuff I tore apart.

However I do want to buy some ESD foam to store all that... if just because it makes them easy to see, easy to grap, and put back, and allow for a compact layout. Any space saving measure I can take, I am willing to consider...

This evening rushed to H/W store just before it closed. Bought 3 little plastic drawer units to get me started in sorting my stuff (not just semis.... all the rest as well...) this evening. They have them in lots of different sizes. Picked two different sizes here to get me started.. will see how it goes and probably get more of them tomorrow as I see fit.


QUESTION : I looked on Ebay to order some ESD foam, but realize that there are TWO different densities available ?! Never realize that until now...

Which one do people recommend ?! I am worried that the denser foam might be might make it difficult to insert packages with thin / fragile legs, never mind large DIP chips with lots of such pins ?  On the other hand I am worried that the less dense foam might not have enough "grip" to hold a TO220 package upright . I guess I can order both and see what works best but... if I could avoid wasting money buying stuff that I won't even end up using....

The low-density stuff is what I've always used. Things with long legs, just slide the pins into the foam at a angle, easy-peasy.

   

Ummm do yourself a favor tho... don't ever Google "power trannies".   

mnem

[mnementh]

What editor you like the most

• vi
  
• nano
  
• emacs
  

?

5-channel paper tape on a 5cps teletype, or edlin, or VAX/VMS edt where you didn't know which word the "delete word" command would delete.

That and vi(le) were probably the source of Smalltalk's "don't mode me in" motto and T-shirt

https://www.tech-insider.org/star/research/acrobat/8108-a.pdf

Huh. 40 years ago.

mnem
*stranger in a strange land*

[mnementh]

bought a PACE pcb repair kit for 45 brussels pesos. To check it out for CPU board repair. Still have my Bungard press for eyelet repair, however I need to redo a couple of traces. Which will be a pain in the intestines

My experience with the Cir-Kits PCB repair product is that the regular kit is okay for proto redesign work, but if you need to make a permanent repair, the Thermobond kit is a must. Otherwise, may as well use copper foil tape and superglue. 

mnem
 

[mnementh]

Ok, so I am officially envy-green now  That Metcal pre-heater is coming in at 450€ here in Germany...

Oh yeah, the new prices are eye watering. I missed one that went for £135 a couple of weeks back (I underbid) and decided to bite the bullet when I saw this one as a buy it now of £180. Tad higher than I'd like to have paid but it looked really clean (and proved to be so) and at least with Metcal you only buy it once. (Whereas anyone who's tempted by the circa £100 China direct preheaters will probably end up buying something else that actually works or doesn't break within a year.) Leastways, that's my excuse for splashing out, and I'm sticking to it.

https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg2560917/?topicseen#msg2560917

mnem
Only cost me 5 bux, but still...   

[dl6lr]

I have seen one of these China "Keysight" USB GPIB... They are very impressive, come in a convincing cardboard box, all the paperwork is inside like expected, the device itself looks spotless.

Made in Malaysia printed on the box. You expect a "Ceryificate" inside the box, don't you? 
Don't ask how I know... Mine is still labelled Agilent.

And yes, they normally work.

I might be tempted by one of these, so I can use GPIB on a modern computer rather than having to use an old bulky dedicated Pentium box... do you have a link to one of these adapters that I could check out ?

They are all spread over eBay, so just buy the cheap chinesium stuff. Be prepared that the USB thingy is at most one tenth of the speed you get from the real metal.

[mnementh]

      ...But now comes a whole new misery: Each half of this duplex is connected to a different breaker. Thankfully, both on the same rail so no 240V differential, but I don't know of any GFCI outlet that'll do 2 circuits in one duplex.

I think I've had enough joy for one night; I'm going to bed.

   

I HAVE THA POWAAAAAHHHH!!!   

So; after making a curbside order at Home Despot for SWMBO to pick up on her way home from work... I have some ground wire pigtails and Greenies to fix the grounding problems, and parts to finish out some heavy-duty extension cords with GFCI outlets in them. I changed nothing in the junction box except tying the grounds together and to the box, and the new 20A duplex is wired exactly the same (tho I did turn it right-side-up): One circuit to each outlet.

There's enough misery to go around without grabbing for more, says I.

Honestly, now that I think of it, this is probably the first time since I left San Antonio that I've actually had power from 2 different breakers within reasonable reach of my bench. now all that's left is to bribe the boi into helping me bring all the heavy-ass bits of workbench into the basement. 

mnem
"Oh the boi... you remember that apple fritter mommy kept you from eating cuz it was for daddy....?"