Test Equipment Anonymous (TEA) group therapy thread

[xrunner]

Check this out. The Time base plug-in and Vertical plug-in are reversed. He sez "seems to work" but then he sez he knows nothing about it. 

 

[med6753]

Attention USA (preferred) and Canada (Customs hassles) TEA addicts. If one of these shows up on a local CL or similar please let me know. I'd like it to be my next project.

The Type 515 size-wise is between the Type 310 and the Type 561.

There was one on Ebay recently but they wanted stupid money.

 

[mnementh]

Yummy hollow-state goodness! Will keep my eyeballz peeled!

mnem
 

[Robert763]

I, don't know about them not working, so far I have bid for and won at various auctions 2 x Solartron 7150 plus's and a lovely Fluke PM3390B scope and all worked perfectly but of course YMMV.

I can assure you it does.

Indeed it does. Sometimes you can see obvious damage or even an unservicable label in the photos, but this stuff is surplus for a reason. Some of it may even have been "de-militarised" making it pretty much scrap. Prices do seem to have gone up since they moved from tender (sealed bid) to on-line auction. I guess you had to have a beter idea of value with a tender rather than just bidding £5 more than someone else thought it was worth.

[mnementh]

ON THE BENCH TODAY: 20 DOLLAH E-SCOOTER!

Picked this up at the Thrift last week... object is to turn this pile of junk into a working scooter. Toolhounds, you may want to look away; that drill is gonna give its speed control to this project!

Part of me is tempted to run 4 conductors of 10ga silicone wires all the way up to the trigger on the handlebars & back; that would allow me to have reverse working as well, just for grins (and my fat ass  ). But man, that's like 20lbs of copper.      I'll probably just remote mount the FET inside the battery box; that 'll keep the heavy wires nice & short.

But first, new brake cables, just for safety.

mnem
"If it don't go, you're walking. If it don't stop, yer fooked." ~grand-dad

[Ice-Tea]

I, don't know about them not working, so far I have bid for and won at various auctions 2 x Solartron 7150 plus's and a lovely Fluke PM3390B scope and all worked perfectly but of course YMMV.

I can assure you it does.

Indeed it does. Sometimes you can see obvious damage or even an unservicable label in the photos, but this stuff is surplus for a reason. Some of it may even have been "de-militarised" making it pretty much scrap. Prices do seem to have gone up since they moved from tender (sealed bid) to on-line auction. I guess you had to have a beter idea of value with a tender rather than just bidding £5 more than someone else thought it was worth.

Even unservicable doesn't always mean bad. It can even mean "heck, we've been calibrating this thing for the last 20 years, what's the point?" or something along those lines. But it's not a good sign, obviously.

[0culus]

...I opened up one of the six identical boards from the 5248M, which seems to have no corrosion. 
The decoder plate is the same as used in the faulty board, I've moved it to the high speed board. Sphere have some of the lower speed boards of this type and I've ordered some.

David

Okayyy... that looks gold-plated from here, at least the final layers. Not the same as the remotes I'm thinking of. First guess is that they laid down silver then gold as a final protective layer. If so, no idea whether you could even make a connection with the conductive pen, even having this nice one to use as a template.

Good thing Sphere has one you might be able to make work... even if the source does make me cringe a bit.

mnem
*toddles off to ded*

What?? 

Sphere is nasty if you’re not in the US or Canada. For one $5 tek IC they wanted to charge me $40 carriage with no insurance.

Well no... it's not any of that. It's the "abattoir" factor.

You want to believe their parts were all "ethically sourced" from dead units according to TEA ethos; but really... it is their business, their livelihood. You know at least a few working units went under the knife, if not most. It's just easier to provide known-good parts if you primarily scavenge from working units. 

mnem
*out into the snowstorm to clear off the car for wifey*

At this point, with a fixed supply of "stuff", sacrifices do have to be made in order to keep things running. And they have had some parts to fix a few things that I had no chance in hell of finding anywhere else other than buying something and cannibalizing it myself.

And yes it's a mom and pop shop...partly why I like to use them. In this day and age of corporate monoliths, it's quite a refreshing experience! My advice is to call them if possible when you need something. I've gotten to know both of them pretty well, and in no way have they ever seemed curt to me.  I am a happy repeat customer, at the very least.

[Robert763]

So I've put the little Delta 300V bench PSU to one of the uses I'd bought it for - reviving sulphated gel-cell (VRSLA) batteries. If left flat these go high impedance and won't take a charge. If they have not left to long they can be revivied by a high voltage very low constant current charge.   
So the Cropico 3001 precison thermometer (pic below) has two 6V VRSLAs one 2.4 AH the other 1.2 AH. They had gone sulphated. I connected the Delta set to 10mA (<C/100) and 200V. I didn't record the peak required to start current flow, but the inital steady state voltage for 10mA was over 60V. Over a few hours this dropped to around 30V. I let the battery sit at less than C/100 until the voltage drops to minimum and then comes up again. Normally it will drop well below the rated voltage of the battery. Once it has come up to a bit above nominal you can switcgh to a constant voltage chagre but current limited to C/10. For the 2.4 AH cell ittook a week to come up to nominal voltage. There are two reasons for the very low charge rate. One is so any cells that are not sulphated are not over charged. Second and most important is to prevent overheating the sulphated cells and drying them out.
The Cropico wont start up on mains without the internal batteries working so it had to be fixed. Capacity is probably well down but at least it is working. Very nice thermometer. Capable of 0.01 deg accuracy (sensor dependent) and 0.001 degree resolution. Works with both RTDs and thermocouples. 

[mnementh]

Well no... it's not any of that. It's the "abattoir" factor.

You want to believe their parts were all "ethically sourced" from dead units according to TEA ethos; but really... it is their business, their livelihood. You know at least a few working units went under the knife, if not most. It's just easier to provide known-good parts if you primarily scavenge from working units. 

mnem
*out into the snowstorm to clear off the car for wifey*

At this point, with a fixed supply of "stuff", sacrifices do have to be made in order to keep things running. And they have had some parts to fix a few things that I had no chance in hell of finding anywhere else other than buying something and cannibalizing it myself.

And yes it's a mom and pop shop...partly why I like to use them. In this day and age of corporate monoliths, it's quite a refreshing experience! My advice is to call them if possible when you need something. I've gotten to know both of them pretty well, and in no way have they ever seemed curt to me.  I am a happy repeat customer, at the very least.

Yeah, but that still doesn't mean I won't cringe a little when I see the harvested organs.

mnem
 

[factory]

...I opened up one of the six identical boards from the 5248M, which seems to have no corrosion. 
The decoder plate is the same as used in the faulty board, I've moved it to the high speed board. Sphere have some of the lower speed boards of this type and I've ordered some.

David

Okayyy... that looks gold-plated from here, at least the final layers. Not the same as the remotes I'm thinking of. First guess is that they laid down silver then gold as a final protective layer. If so, no idea whether you could even make a connection with the conductive pen, even having this nice one to use as a template.

Good thing Sphere has one you might be able to make work... even if the source does make me cringe a bit.

mnem
*toddles off to ded*

What?? 

Sphere is nasty if you’re not in the US or Canada. For one $5 tek IC they wanted to charge me $40 carriage with no insurance.

Well no... it's not any of that. It's the "abattoir" factor.

You want to believe their parts were all "ethically sourced" from dead units according to TEA ethos; but really... it is their business, their livelihood. You know at least a few working units went under the knife, if not most. It's just easier to provide known-good parts if you primarily scavenge from working units. 

mnem
*out into the snowstorm to clear off the car for wifey*

At this point, with a fixed supply of "stuff", sacrifices do have to be made in order to keep things running. And they have had some parts to fix a few things that I had no chance in hell of finding anywhere else other than buying something and cannibalizing it myself.

And yes it's a mom and pop shop...partly why I like to use them. In this day and age of corporate monoliths, it's quite a refreshing experience! My advice is to call them if possible when you need something. I've gotten to know both of them pretty well, and in no way have they ever seemed curt to me.  I am a happy repeat customer, at the very least.

Well at least they didn't charge the extortionate prices some ePay dealers want for similar untested counter boards. No guarantee all the boards from Sphere work either.

David

[factory]

Well it should have been obvious why the HP neon/photo-resistor decoders were different, the two designs are needed because the earlier ones used 1,2,2,4 binary code and the option 002/003 & 5248M I have use 1,2,4,8 binary code. Something to be aware of if boards have been swapped & the readout is incorrect.

I've confirmed the repaired high A18 readout board from the 5248M works, using a separate power supply to provide around -13V to -14V to drive the binary inputs (temporary wires added).


Hopefully the parts from Sphere will fix the lower speed display board I borrowed the decoder plate from.

Just need to sort out the remaining fault(s) with the A21 function control board, it seems to be passing a signal to the display counters when the gate is inactive and any input (or the internal check signal) is very intermittent when the gate is active. The area in question has had a lot of repair work done in the past.

Back at work tomorrow, so won't get much time to carry on with this till the end of year shutdown. 

David

[med6753]

Yummy hollow-state goodness! Will keep my eyeballz peeled!

mnem
 

I'm slowly retrograding. Soon I'll have more hollow state gear than solid state gear. 

[med6753]

Well no... it's not any of that. It's the "abattoir" factor.

You want to believe their parts were all "ethically sourced" from dead units according to TEA ethos; but really... it is their business, their livelihood. You know at least a few working units went under the knife, if not most. It's just easier to provide known-good parts if you primarily scavenge from working units. 

mnem
*out into the snowstorm to clear off the car for wifey*

At this point, with a fixed supply of "stuff", sacrifices do have to be made in order to keep things running. And they have had some parts to fix a few things that I had no chance in hell of finding anywhere else other than buying something and cannibalizing it myself.

And yes it's a mom and pop shop...partly why I like to use them. In this day and age of corporate monoliths, it's quite a refreshing experience! My advice is to call them if possible when you need something. I've gotten to know both of them pretty well, and in no way have they ever seemed curt to me.  I am a happy repeat customer, at the very least.

Yeah, but that still doesn't mean I won't cringe a little when I see the harvested organs.

mnem
 

It's a fact of life. I often purchase non working equipment for the sole purpose of harvesting parts. The difference is that I don't do this to sell and make a profit. Instead I do it to maintain the equipment I do have. Without that stock of dead equipment half my stuff that DOES operate would also be in the pile. Now on very rare occasions I have sold parts to fellow Tek owners. But it's usually small stuff. The largest piece I've sold is a functional DM44 for $50 that came off a dead 465B.     

[bd139]

Yep same. I bought that 475 for I think £2 just to eBay the parts off. Turned out it worked with some arguing  and some 465 corpse parts

[med6753]

Yep same. I bought that 475 for I think £2 just to eBay the parts off. Turned out it worked with some arguing  and some 465 corpse parts

I've had the supposed non working parts unit be in better shape than the one I was working on. The 2430 comes to mind. So mine became the parts unit and I fixed up the purchased one. 

[vk6zgo]

Smart draftsman uses all the prefixes

And don't use ".".

Current gudance is use the multiplier letter as the decimal eg   0u1 4n7 2M2  0R1 etc.

Sorry, I'm old school. The decimal point is in play. Along with K = 1000. So a 2200 ohm resistor will be 2.2K.

 

Yeah!
It seems strange that we can all happily use decimal points with money, but are too stupid to realise when some circuit designations don't make sense!
It's the same mentality which has ginormous lengths of timber sold in mm instead of metres.

[vk6zgo]

...How wrong I was, unfortunately damp has got inside the block & eaten away some of the traces on the photo-resistor plate and this plate is the main difference in this display board between the 5248 & the 5245 models.

Before & after cleaning with IPA,         Looks like I'm stuck with only 7 usable digits unless/until I can find a replacement.     (SNIP)

David

Aww, man... that truly blows. Think there's any chance of resurrecting with a silverized conductive pen? I can't think of a better candidate to at least give it a try.

mnem
 

Back in the '70s, as the gaps in the tracks were only small, I tried solder-------bad idea!
Soon the gaps were much larger.

Silverised conductive paint wasn't mainstream back then, as most car rear window defrosters were actual nichrome wire embedded in the glass.
When the deposited ones took off a few years later, silver paint became a stock auto parts item, so you didn't have to "ring around" to find the stuff.

I wonder if it would be easier, (although not original) to use a PIC to do the decoding & just connect the resultant decoded signals to the display via appropriate level interfaces.
OK, "easier" is relative, as it would probably entail designing a whole new readout board.

[Cerebus]

Yeah!
It seems strange that we can all happily use decimal points with money, but are too stupid to realise when some circuit designations don't make sense!
It's the same mentality which has ginormous lengths of timber sold in mm instead of metres.

As someone else already pointed out, it's not uncommon for component values, or current measurements, in a circuit to cover a huge range of values. A capacitor microphone preamp might easily include 10G ohm resistors and 100 ohm resistors. We use money for things that we've got, at first sight, a good grasp on the general price that they ought to have (a car, a loaf of bread, and so on), we'd spot a crazy value much faster than we might in an unfamiliar circuit.

[vk6zgo]

Yeah!
It seems strange that we can all happily use decimal points with money, but are too stupid to realise when some circuit designations don't make sense!
It's the same mentality which has ginormous lengths of timber sold in mm instead of metres.

As someone else already pointed out, it's not uncommon for component values, or current measurements, in a circuit to cover a huge range of values. A capacitor microphone preamp might easily include 10G ohm resistors and 100 ohm resistors. We use money for things that we've got, at first sight, a good grasp on the general price that they ought to have (a car, a loaf of bread, and so on), we'd spot a crazy value much faster than we might in an unfamiliar circuit.

Some of us have, at first sight, a good grasp on the general values used in most circuitry!

[mnementh]

Well no... it's not any of that. It's the "abattoir" factor.

You want to believe their parts were all "ethically sourced" from dead units according to TEA ethos; but really... it is their business, their livelihood. You know at least a few working units went under the knife, if not most. It's just easier to provide known-good parts if you primarily scavenge from working units. 

mnem
*out into the snowstorm to clear off the car for wifey*

At this point, with a fixed supply of "stuff", sacrifices do have to be made in order to keep things running. And they have had some parts to fix a few things that I had no chance in hell of finding anywhere else other than buying something and cannibalizing it myself.

And yes it's a mom and pop shop...partly why I like to use them. In this day and age of corporate monoliths, it's quite a refreshing experience! My advice is to call them if possible when you need something. I've gotten to know both of them pretty well, and in no way have they ever seemed curt to me.  I am a happy repeat customer, at the very least.

Yeah, but that still doesn't mean I won't cringe a little when I see the harvested organs.

mnem
 

It's a fact of life. I often purchase non working equipment for the sole purpose of harvesting parts. The difference is that I don't do this to sell and make a profit. Instead I do it to maintain the equipment I do have. Without that stock of dead equipment half my stuff that DOES operate would also be in the pile. Now on very rare occasions I have sold parts to fellow Tek owners. But it's usually small stuff. The largest piece I've sold is a functional DM44 for $50 that came off a dead 465B.   

This is precisely what I was talking aboot... this is the best side of "ethically sourced parts". You bought two deaderzz to make one working unit... and in the process, you helped someone else fix one of theirs, so 2 working units plus a few dollars for more TEA. Lather, rinse, repeat.

That clearly is not the same as I was talking aboot in my earlier post.

mnem

[Cerebus]

Some of us have, at first sight, a good grasp on the general values used in most circuitry!

Perhaps you do, perhaps you don't. The question is, does the technician you hand the, photocopied, faxed and photocopied again, schematic to have the same breadth and depth of knowledge? Is he/she likely to know instinctively the correct values in an electrometer, a 3kW motor drive, a sonar buoy and a distance sensing microwave transceiver equally well?

[cyclin_al]

Some of us have, at first sight, a good grasp on the general values used in most circuitry!

Perhaps you do, perhaps you don't. The question is, does the technician you hand the, photocopied, faxed and photocopied again, schematic to have the same breadth and depth of knowledge? Is he/she likely to know instinctively the correct values in an electrometer, a 3kW motor drive, a sonar buoy and a distance sensing microwave transceiver equally well?

Hey! I resemble that remark.  To be honest, I am one of those for whom it is neither instinctive nor intuitive.  I do not have the breadth and depth of knowledge in electronics.  I do have a background in systems engineering, so I can eventually figure it out.  However, it is going to take me some study and analysis work, and a whole bunch of time.  When it comes to repairing something, I much prefer a notation that is unambiguous, since my usual goal is to get that something working and learn a few things along the way.  Deciphering values, not so much ....

[med6753]

Some of us have, at first sight, a good grasp on the general values used in most circuitry!

Perhaps you do, perhaps you don't. The question is, does the technician you hand the, photocopied, faxed and photocopied again, schematic to have the same breadth and depth of knowledge? Is he/she likely to know instinctively the correct values in an electrometer, a 3kW motor drive, a sonar buoy and a distance sensing microwave transceiver equally well?

That's why it's important for the draftsman to have good notes on his schematics which specify what parameters are used. Here's an example of a schematic I drew up for my own use. The notes specify for example resistor parameters and specifically that "K" means 1000.

[mnementh]

I just tripped over this while looking for inserts for my iPod dock...   eBay auction: #182909336044

mnem
 

[med6753]

Includes a lock of Steve Job's hair.