Test Equipment Anonymous (TEA) group therapy thread

[bd139]

I thought that was a prank 2N3055 for a minute 

[Neomys Sapiens]

The HP 6177B DC Current Source I mentioned the other day arrived well packaged and undamaged by its journey.  It's pretty grubby looking, and will need some serious cleaning to pretty it up.
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.
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-Pat

Good luck with it. Mine has all those substantial modifications which are described by sparse text only, so I don't see it coming back to life in the near term. You look at the manual and the device - and you don't recognize anything!

[factory]

hp 3310A sine wave output problem part two.

As I mentioned last night the 3310A hadn't been used for a while, I tested it and found the sine wave output was almost a flat line. I dug out the dead tree manual earlier and checked the PSU rails first, no problems there.


Onto the relevant circuit diagrams, for the output from the triangle stage (working OK), this goes to the sine shaping network on the A3 board and the sine shaper amplifier on the A2 board.



The front panel controls were set as specified for the DC voltage checks, I then checked the voltages for the transistors (Q1-Q6) on the A3 sine shaper network section, all voltages were fine here.

I moved onto the A2 sine shaper amplifier section and checked the voltages around Q1-Q4, some voltages around Q2/3 were way out, as shown below.



It was switched off and I checked for the problems with the DMM on diode check, Q2 was found to be shorted C-E, another part marked 4-071 (aka 1854-0071) a common faulty part in hp TE of this vintage.


The book says they used aged parts for Q1 & Q2 of 5080-4668, no chance of finding any of those.


So I found a used 4-071 from a scrap board, pinout was verified with the recently acquired Peak DCA and compared with the working Q1, they are the same part & manufacturer but do indeed have a different pinout, again typical of hp they used whatever met their spec & had them labelled the same. 
4-071 is a selected 2N3704 according to the pdf 3310A manual, I think I've seen several other standard parts they used for this one.


Gain/hFE measured by the Peak DCA was 423 for Q1 and 430 for the replacement Q2, the salvaged part was fitted, the voltage at R13 was +6.28V & R16 +6.97V, both back in spec.


Got the scope out again, the sine function was back, I rechecked all functions (except the VCO input) and found no other problems. 


David

[factory]

Extra pics for above post.

[Neomys Sapiens]

Tek RM17 scope repair update



So I need :

- A small vice that can be quickly and easily be secured to the bench.

I would not call my current vice small, but rather petite, and I will not tell about the second part. 

But I concur that a small vise would be a valuable addition to your lab. Even if lambasted by Mnem and maybe others, I still recommend the Bernstein Spannfix for such applications.

[Robert763]

I think I just stuck my nose in a very deep, dark rabbit hole 
I just aquired a 3D printer.......
Well at least it was free. Appeared on Trash Nothing locally. It's an early RepRap a Mendel by the look of it. Needs a bit of work.....

   

If this is your first... I'd recommend putting it on the shelf forgetting you ever saw it and getting something more noob-friendly. I'm not sure you can even strip it for usable parts... maybe a stepper or two; but not likely even a civilized controller on the thing, most likely a RAMPS 1.2 or older.

The Mendel is an invitation to misery; everything wiggles and wobbles because it's literally made of TinkerToy bits and design.

It was a groundbreaking something decades ago. Nowadays... not even equivalent to a Model T.

I know you're a engineer... and I know you probably figure you can figure anything out. I was the exact same way when I started in 3DP; I had a lot of experience building jigs and material-handling with 8020 extrusion, so I figured a cheap kit like the Tevo Tarantula would be a piece of cake.

So-o-o-o-o not the case.     I mean... if you're not a 3DP noob and you're looking for a challenge, the Mendel will certainly provide it...

mnem
The 1st mantra of 3DP: Build it straight and square, straight and square, straight and square... 

Yes that is the one. I do have some concerns about it..... I think it has a later controller if so I might consider a bit of re-engineering.

[Neomys Sapiens]

Correct. If I can leave the original can in place and install new capacitor on a terminal strip under the chassis I will. But if there's no room under the chassis the can is pulled and capacitors mounted top side on terminal strips like this....

And our resident blue guy seems to channel a certain green guy! The force might spare you the hernia, but those ears won't fit under the smurf cap!

[Neomys Sapiens]

Just wanted to look around at discord and tried to register for an account.

But obviously I'm to old to manage the capcha. Not able to identify bicycles, water planes nor trucks. 
Or maybe I'm a machine and should just join my TE on the shelf, then do the final shutdown? 

Edit: Did a little research. Problem seems to be common. Advice is to reset lots of stuff on the system: change IP, delete all cookies, bla bla ...; basically they suggest to do a fresh and complete windows reinstallation before able to use discord. What a crap. 

Ok. This world machine is indifferent about mine beeing human or machine by telling me my mind or the world might be indifferent about bicyles or water planes. Maybe i should just try to cross the river Elbe by bike today afternoon? 

What will happen? Place your bid:
a - the bike will swim
b - the bike will fly
c -captcha will be asking to mark submarines next time

Think I'll just stay away from that kind of badly implemented sh... .

You shall be classified as a water vehicle from now. Please attend immediately to German Lloyd for a seaworthiness assessment. And don't forget to show the proper light signals at night!

[0culus]

I'm back, sorta. Much like bd I've been moving. Thankfully that is pretty much done.  Then work projects started coming at me. 

I've started falling off the wagon on ePay again lately. Buying microwave components for a radar project I want to build. So far I've scored a couple of X band mixers for reasonable prices.

[Vince]

Tek RM17 scope repair update



So I need :

- A small vice that can be quickly and easily be secured to the bench.

I would not call my current vice small, but rather petite, and I will not tell about the second part. 

 

Vise is American, vice is the proper English spelling   

At least that's what Google tells me... so I stick to that.

It's like tire / tyre, or the way to pronounce "schedule" either " SKEEE "or " SHHH "...
The problem in international forums is that all "versions" of the English language are mixed up, so for a foreigner like me it's difficult not to be confused... I am sure I must sometimes write inconsistent sentences that mix both American and British English words, without even realizing it. Must look weird to both American and British friends, but well.... 

I do the best I can...

But at least I did recently wonder about vise / vice because it was bothering me. So I googled it. I prefer to use proper British English because well, it's the actual, original language, the reference. Others are just variants that mutilate the original. Also, being French, England is very close to me of course, and that's where I studied EE for 3 years, so I feel close to that language, unlike the US that is a very weird exotic remote country to me.
For starters, you will never see me write "colors" instead of "colours", or "aluminum instead of "aluminium", and so on ! 
Or a brake "rotor" instead of a brake disc. I try to be consistent and use British English but it's an on-going battle to try to figure out what's what 

[0culus]

As far as I'm aware, "vice" could be defined as say....TEA...and a "vise" is a device for holding work pieces in the shop. 

[Vince]

hp 3310A sine wave output problem part two.

...
I moved onto the A2 sine shaper amplifier section and checked the voltages around Q1-Q4, some voltages around Q2/3 were way out, as shown below.
It was switched off and I checked for the problems with the DMM on diode check, Q2 was found to be shorted C-E, another part marked 4-071 (aka 1854-0071) a common faulty part in hp TE of this vintage.
The book says they used aged parts for Q1 & Q2 of 5080-4668, no chance of finding any of those.
So I found a used 4-071 from a scrap board, pinout was verified with the recently acquired Peak DCA and compared with the working Q1, they are the same part & manufacturer but do indeed have a different pinout, again typical of hp they used whatever met their spec & had them labelled the same. 
4-071 is a selected 2N3704 according to the pdf 3310A manual, I think I've seen several other standard parts they used for this one.
Gain/hFE measured by the Peak DCA was 423 for Q1 and 430 for the replacement Q2, the salvaged part was fitted, the voltage at R13 was +6.28V & R16 +6.97V, both back in spec.


Got the scope out again, the sine function was back, I rechecked all functions (except the VCO input) and found no other problems. 

David

Ah, see it was quick ! 

You really scare me with this part numbers and random pinout shit show on old HP gear, make me run away !!!

Not sure I want to start a collection of old HP stuff  when I read that... 

At least the manual tells you what is the original / actual part number hiding behind the HP P/N, so you can just grab of these... and triple check the pinout ...

As for aging well you can just stick any tranny on the board and see what that does... if really it's way off you can always age them yourself, make a little test jig and age 20 of them or so in one go, and keep them in stock....

It would interesting to know how, and how long, did HP age them, so one can reproduce their process.

But luckily your salvaged one did the job 

[Vince]

I am not even sure Kicad PCB editor can do that ?! 
I guess I will find out....

At least it can get close. This is like 15 minutes and it's really ugly. But yes, you can do it.  I tried to follow your measurement notes. 

Obvious improvements:

• Select metric in the drawing (or convert your metric measurements back to the Freedom Units  Tek used)
• Measure more carefully and compare with original.
• Select capacitor footprints that actually correspond to the ones you're using
• Same but for solder turrets / tags.
• Re-do the horrible ground mask.

Wow, thanks a bunch ! 

So you managed to make the " TO-3 " ovoid shape, so it's possible then, cool ! 
Now I need to see if there is a function to rotate pads or objects, or groups of objects, by XX degrees, so I can arrange the 3 terminals for the sections of the cap.

The idea is not to make a PCB specific to that cap, but make a general purpose board that mimic the mounting plate, so that it can be used to any can cap in the future.

So i need to use terminal of the same shape (not turret like),, shaped like  rectangles with a 2 or 3mm hole in them, like the originals, and locate and orient them in the same way as the iold cap, so that the existing wires and solid links, can "fall" perfectly into place. This way it will be a turn-key solution, and all wires will be super easy to solder back onto the cap. Thing is, all these wires are either solid core, or so stiff that it's like they were solid. There is no play in them, so it's important that the terminal and their placement on the board, are identical to the old cap.

Also I think I could use the solder mask to draw / mimic the symbols  that engraved on the mounting plate, to identify the 3 sections of the cap : a square, a triangle and a half moon.


Midnight here, tired... will start playing with Kicad tomorrow ! 

Terminal that might do the job, from my local electronics shop :

https://www.e44.com/connectique/connecteurs/fiches/Cosses-plates/Male/cosse-male-4.8mm-ci-nue-lot-100pieces-VC480M.html

I would need I think to enlarge the hole in them a bit, but easy enough.

Or also maybe, while browsing Farnell's website I spotted this style of terminal that could be interesting :

https://fr.farnell.com/harwin/h2051-01/borne-tourelle-1-68mm-non-isolee/dp/3932897?st=cosse%20souder

What I like in this shape of terminal is the deep slit that makes it even easy to secure a wire in place but makes it even easier to place the wire than having to get it to through a hole.
Also, the two "posts" of the fork could also be used to wrap a wire around it. So it's quite versatile and easy to work with. I am tempted t try them out...
Anyway since I am at the prototype stage, it's a first design... the idea is to try things and see what works best. I am sure there will be a new iteration of the board at some point, to fine tune the design...but I gotta start somewhere and try it out in the real world....

[Cerebus]

As far as I'm aware, "vice" could be defined as say....TEA...and a "vise" is a device for holding work pieces in the shop. 

It's all a question of whether you're using your vice/vise to hold a king dick or not.
























What!?! it's a well known brand of British spanner. What did you think I meant?

[med6753]

Correct. If I can leave the original can in place and install new capacitor on a terminal strip under the chassis I will. But if there's no room under the chassis the can is pulled and capacitors mounted top side on terminal strips like this....

And our resident blue guy seems to channel a certain green guy! The force might spare you the hernia, but those ears won't fit under the smurf cap!

I have figured out careful methods for jackassing 500 Series scopes around without killing myself. 

[Neomys Sapiens]

Tek RM17 scope repair update



So I need :

- A small vice that can be quickly and easily be secured to the bench.

I would not call my current vice small, but rather petite, and I will not tell about the second part. 

 

Vise is American, vice is the proper English spelling   

At least that's what Google tells me... so I stick to that.

It's like tire / tyre, or the way to pronounce "schedule" either " SKEEE "or " SHHH "...
The problem in international forums is that all "versions" of the English language are mixed up, so for a foreigner like me it's difficult not to be confused... I am sure I must sometimes write inconsistent sentences that mix both American and British English words, without even realizing it. Must look weird to both American and British friends, but well.... 

I do the best I can...

But at least I did recently wonder about vise / vice because it was bothering me. So I googled it. I prefer to use proper British English because well, it's the actual, original language, the reference. Others are just variants that mutilate the original. Also, being French, England is very close to me of course, and that's where I studied EE for 3 years, so I feel close to that language, unlike the US that is a very weird exotic remote country to me.
For starters, you will never see me write "colors" instead of "colours", or "aluminum instead of "aluminium", and so on ! 
Or a brake "rotor" instead of a brake disc. I try to be consistent and use British English but it's an on-going battle to try to figure out what's what 

I'm completely with you on the merits of staying with British English. Despite having been tought this way, I was sure that the definition given by Oculus would still apply. If not, you got a point on me! But nevertheless, your wording was so neatly fitting the case...
(named vice approves)

[BU508A]

- A small vice that can be quickly and easily be secured to the bench.

Proxxon FMZ: https://www.proxxon.com/de/micromot/28608.php

ebay: https://www.ebay.de/itm/192916566100

Proxxon FMS 75 (this one I have): https://www.proxxon.com/de/micromot/28602.php

ebay: https://www.ebay.de/itm/203289086706

NAWTS

[TERRA Operative]

Hey Vince, what about strategic use of masking tape to hold your thing to the bench?
I go through a reasonable amount of tape holding stuff here and there and most of the time it works just well enough and long enough to get the job done.

[Vince]

Hey Vince, what about strategic use of masking tape to hold your thing to the bench?
I go through a reasonable amount of tape holding stuff here and there and most of the time it works just well enough and long enough to get the job done.

Come on  ! 

Need to hold the piece FIRMLY, and be able to orient it as required,  if I want to use tools on it ! 

Pry things apart with a screw driver while melting the solder like was the case here.
Or use a fine fine, or a hack saw or whatever...

Plus tape doesn't hold well on my dirty OSB top ! 

[vk6zgo]

Wouldn't need a box. Seriously. They are squaddie-proof, as shown in https://www.eevblog.com/forum/testgear/fluke-8125a-military-dmm-teardown/msg2540745/#msg2540745

There is a hierarchy of X-proofness that I have garnered from my real-life experience over the years. I don't propose to list it in full here, but an excerpt, in order of increasing required robustness would include: X such that X is in the ordered set {..., squaddie, policeman, musician, drummer, actor, postman, ..., AvE, Dave, ...}

I would like to propose adding "Engineering student" pretty early in the set.  Having peripheral experience from the sound and lights department at a student union, I argue that the sheer ingenuity in inventing new ways to break things counts for a suitable placement.

EE, TV Production person, Manager.

[vk6zgo]

Hey Vince, what about strategic use of masking tape to hold your thing to the bench?
I go through a reasonable amount of tape holding stuff here and there and most of the time it works just well enough and long enough to get the job done.

Gaffer tape might do the job!

[Vince]

- A small vice that can be quickly and easily be secured to the bench.

Proxxon FMZ: https://www.proxxon.com/de/micromot/28608.php

ebay: https://www.ebay.de/itm/192916566100

Proxxon FMS 75 (this one I have): https://www.proxxon.com/de/micromot/28602.php

ebay: https://www.ebay.de/itm/203289086706

NAWTS

Yes I would like something like that.  I like the ball joint very much so one can orient the work piece, that's neat.
The suction cup base would not work for me as I have a dirty OSB top, suction cup needs flat smooth hard surface to work well.
So I would need the C clamp version or whatever it's called. However this particular vice won't do it as the clamp can only open 60mm wide and my bench is 65mm thick or something, depending where you measure, so would need at least a 70mm opening to be sure I can fit it anywhere along the bench, without having to hammer it into place...

I think there might be a solution... bench is so thick only because the piece of wood / cross beam that supports the OSB panel is 50mm thick. But I guess I could push the cross beam just a few centimeters to let the C clamp bite.  This way I could use my existing vice, or by that one with the cool ball joint. Problem is that the edge of the OSB top will now not be properly supported any more and therefore be fragile, especially when I throw a boat anchor at it.  So I am reluctant.

I think I will not move that cross beam. Think cheapest way is to just clamp my existing vice onto a piece of wood and then clamp the wood piece onto my bench, using a small C clamp. A small C clamp is cheap and wood I have plenty of in stock. It's not practical, means I have to keep 3 pieces together : the vice, the wood piece and the clamp, instead of just having the one vice, but I gotta find a compromise somewhere.

Oh ! Another idea... maybe I could, again, keep my wooden cross beam in place, not move it backward BUT... just trim it just enough, in one small spot, just enough so I can get the clamp of the vice to grab the edge of the bench. It would weaken the beam a little bit but not too much I think. It's 50mm thick so it would get thinned down to15mm but only on its edge, like 3 or 4 cm deep tops, and it's 150mm wide so that's OK, still plenty of wood to support the OSB top.

Yes... might be more practical.... of course that means I can only install the bench in one single particular spot on the bench, say in the middle, but it's where I would want it most of the time anyway so... sounds like a reasonable compromise for now. Yeah, think I might do that !  So tomorrow, some wood trimming and some Kicading ! 

Thanks for the brainstorming chaps, it was fruitful ! 


But for now... 2AM so... 

[mnementh]

   I mean... if you're not a 3DP noob and you're looking for a challenge, the Mendel will certainly provide it...

Yes that is the one. I do have some concerns about it..... I think it has a later controller if so I might consider a bit of re-engineering.

If by re-engineering, you mean strip out all the electronics and build a new chassis from scratch out of 4040 extrusion , that might be something slightly less painful than rebuilding the Mendel design, which is going to be roughly akin to sticking your pecker in a running corn sheller and hoping for the best. 

The main problem is the prehistoric geometry; the common predefined profiles for it will likely not have a lot of the current popular features preconfigured; you'll have to do the deep dive on Marlin before you can even start. Everything current is some variant of i3, which is what the Ender series are.

The least assache from a noob perspective would be a kit of 2040/4040 you could just put your electronics on... But such kits are cheapest made China-direct by far, and they'll already have the electronics on them.

Designing it yourself sounds like fun... At first. Then you realize quickly how all the little fiddly bits just nickel & dime you to death. 

I actually started down that road with the Tarantula kit... Eventually I got my Tornado which was a 30-minute build as I've chronicled in here. After I had that for about 6 months, I realized stockpiling leftover Tarantula parts was mostly wasted space... So I gave away my 2nd unbuilt kit.

I know there's a point in here somewhere... Oh yeah. I'm pretty sure the previous owner of that Mendel was at exactly the same point as I was when I gave mine away.  There's a reason it was "free". 

Don't let yourself get too involved in this old 3DPrinter.  If you really think you want to dip your toe in this rabbit-hole, do yourself a favor and spend some money up front on a modern, civilized machine. Any modern i3-based model will be less assache, even a basic Ender3 for ~$180.  If you want a machine that's Lego easy and you can afford a bit more than the E3, (~$350) I can vouch for the CR-6SE. It is as close to a painless build as you're gonna get (4 bolts and plug in some ribbon cables) and when you're done it will set itself up automatically. Plus, it comes with all the "essential upgrades" everybody does to the E3 to make it a civilized 3DP.

2 years later, mine is still the first 3DP reach for.

Cheers,

mnem
Your time is your most valuable capital; spend it wisely.

[mnementh]

...A small vice that can be quickly and easily be secured to the bench.

EDIT: Rather than cut out on the edge of your bench, perhaps it would be better to screw a bit of 1x1 to the edge so it's flush with the surface. 

      

I have these. Well, all 3 heads and 2 of the flat bases. The vises themselves can be swapped between the standard swivel heads without tools. I keep the third swivel base on the shelf in case I need to screw it down somewhere to get a quick lick of work in. I also have a couple leetle ones like yours, and a 5" mechanic's vise bolted to my back bench in the back half of the basement.

They all get used at one time or another. The PanaVise that looks like a regular vise will hold well enough to cut with a Dremel or razor saw or do filing; if I need to do some hacksawing, I just hold it down to the workbench with a big C-clamp on the baseplate.

mnem
 

[Zoli]

...
Now I need to see if there is a function to rotate pads or objects, or groups of objects, by XX degrees, so I can arrange the 3 terminals for the sections of the cap.
...

Yes, there is a function, and(not surprisingly, considering all the inconsistencies/sarcasm off) is called move exactly(shift+m; kicad6.0.x); the third line specifies the angle, the fourth the centre of the rotation. I've used a lot when I've made a pentagon shaped PCB; Ctrl+Z is your friend.
Edit: it works on multiple selected items, either as move, or rotate; all layers included.