Test Equipment Anonymous (TEA) group therapy thread

[beanflying]

No need to fisticuffs just rational real world experience compared to 'being generous' over stated BS from someone with about zero real world use is and currently remains the issue.

I was thinking on this much earlier in the day about the first soldering iron and the kits I tried assembling. Sometimes it got the job so hot the tracks fell of and the odd early IC failed. These days with practice, real world experience and use flicking on my modern irons and even with aging eyes and shakey hands from the coffee intake I can manage a reasonable job on 0603's if I have to. Doesn't mean I want to do it for a living but it is easy with modern gear and practice.

3D printing is similar but the rate of advancement and simplicity of use compared to only a few years ago is dramatic and with some actual use and practical application the results are fairly good and fairly easy to achieve and getting better all the time.

I will drop my settings up tomorrow to for the Ender and CR-10S to suit the new version of Prusa Slicer (brand new version of sli3erPE). Won't be perfect but it will be close for the same printers and PLA or PETG, most likely just tweak the retraction settings by +-1mm for a start but otherwise will get you rolling. I resisted changing from the old sli3erPE for a while but easy to save out your settings and then upload them into the current and much improved one https://github.com/prusa3d/PrusaSlicer/releases

[bd139]

On topic, which is better for noobs like me? Cura or PrusaSlicer?

Cura has a machine profile for the Ender 3 already in it.

[beanflying]

Looked at Cura when I got the CR-10S and sli3er then jumped at sli3erPE as it was better than the stock one and stuck with it. Pros and cons of both but I found PE at the time to be a much better user experience over Cura.

I should look at Cura again but Prusa is upgrading and adding more features quickly so it is unlikely I would change.

My profiles would get you started into Prusa so try both and see what you like.

[xrunner]

More play-time with the NanoVNA. I was looking at my antenna on port 0 and thought I'd see if it could be used as a basic spectrum analyzer. I connected the antenna to port 1 and set it to 820 kHz center. It clearly showed the local AM station there. Of course it doesn't have the help of a pre-amp but one could be added externally.

It's really an amazing little thing for $50 or even less.

[med6753]

Re-cap of the B&K 1810 Frequency Counter. Only 3 aluminum capacitors but the entire board had to be partially disassembled and removed from the chassis to gain access to the bottom of the board. It's done and back on the standard to cook for a while.

Shhh...don't tell mnem but the POS Vastar soldering station performed flawlessly again. In fact, even better with the installation of a chisel  tip.

Next on the agenda is the 485 twins back on the bench. But that won't be today nor tomorrow. The balance of today I'm going to do nothing...because I can. Tomorrow need to do a coolant change on the Honda CR-V and then it will be ready for Winter. So probably Tuesday.

[xrunner]

On topic, which is better for noobs like me? Cura or PrusaSlicer?

Cura has a machine profile for the Ender 3 already in it.

I've only used Cura but as was said it has a profile for Ender already. I'd go with it for now and a little later you can try and use others as you have time. It works for me and I don't want to change the system right now. 

We'll talk about something called Octoprint at a later date ... 

[worsthorse]

The Tek 106 goes on the bench today. After that, the two Tek 191s. I was going to do the 191s first but decided that I didn't want to deal with this right now:



Yes, a transistor case with 5 to 300V on it under normal operating conditions. 

If I can get the bench time in, I should have at least six pieces of gear ready for sale at the Salem hamfest.

Photos and report on the 106 to follow.

[bd139]

Ah yes the hybrid tube / transistor circuits of the early 60s. Quite a bit of fun those. Ooh hello Mr Transistor, let me see if you are hot. Bzzt. Ouch! Been there 

[med6753]

Well I did something REAL dumb this morning. Grabbed a terminal that had mains voltage (120V) on it. Luckily my finger tips are so callused that there was hardly a twinge and I even had time to say to myself "dumb ass!" before pulling away. 

[BU508A]

The second device which showed up on saturday is the Fluke 732A which I stumbled over by chance on Thursday evening.

It is now online for about five hours and the thermistor inside of the oven stabilized at 3475.4 Ohms.
It started around 13kOhm. The output itself looks very clean and now stable at 10.000184V.
Will monitor this further.

I did not open the case of the 732A, first I'll do some readings and looking for the manual.
I think TiN has a copy on xdevs.

Here are some pictures:

Front side, the binding posts. Look at the different colours of the metal inside.
I think, the red ones are the CuTe ones and the yellow-ish ones are brass.


It has sticker all over it and by the looks of it it was used by the air force of the Bundeswehr (German Army).

Luftwaffenwerft 84:


The "ID-card" of this thing:


"Do not remove seal"


Inventory number


electrical checkup was ok in 2015 and since then the unit wasn't opened.


The batteries were changed in 2014 and last tested in 2015


low voltage power input:
Is this some kind of Lemo connector? Does anybody know?


Last calibration July, 27th 2015


Next calibration: July 2016 (which didn't happen, I think)


Online for around 120min:


Up now for around 5h


Screenshot from the DMM7510:


Will check what it is doing tomorrow. And I'm curious how the batteries behave.
The LED for the battery charging shines but I suspect, that the batteries are dead after this long time offline.

Will keep you updated.

[BU508A]

Well I did something REAL dumb this morning. Grabbed a terminal that had mains voltage (120V) on it. Luckily my finger tips are so callused that there was hardly a twinge and I even had time to say to myself "dumb ass!" before pulling away. 

That was real luck!         

Try the same with 230 or 240 Volts AC and you can significantly increase your "user experience".   

[bd139]

Yeah you really learn to respect 230V, if your first time isn't your last time

[worsthorse]

yeah, i see that 450V label on the 191 schematic and i think, mebbe i'll work on something else today.

here's one of the pieces of equipment listed in the 106 calibration procedure:



This is a 60ns delay line (100ps rise time). It weighs 59 pounds. I think I will find a workaround rather than buy one. 

Last word on the 114. Some gorilla forced an 8-32 screw into a tapped hole meant for a 6-32. All the mis-matched hardware now replaced. As suspected on the ringing I saw, my cheap BNC jumper cables were part of the problem. I dug up my box of Tektronix cables, subbed one in, and ninety percent of the problem disappeared. Now burning in the box to be sure nothing else lets loose but on to the 106 this afternoon.

[BU508A]

I hope you guys have an emergency switch in your lab.

This is an example on NOT how to do it.       



(but I think this is  (hopefully) a fake / prank / kind of a joke) 

[bd139]

  That's almost as bad as the portable ground

[0culus]

Well I did something REAL dumb this morning. Grabbed a terminal that had mains voltage (120V) on it. Luckily my finger tips are so callused that there was hardly a twinge and I even had time to say to myself "dumb ass!" before pulling away. 

Hah! I did that the other day while working on that current probe. My pinky touched the hot terminal on the mains fuse case. 

[0culus]

Got my hands on some 2 pF ceramic caps, so I gave the avalanche pulser another go, this time using Manhattan style construction. It works! There's still some optimizations to be done, such as getting some high quality 50 ohm resistors instead of paralleling a pair of 100 ohm resistors, and shortening leads some more. Then make it fit into a BNC project box. But, I'm happy with this prototype! [edit] yes, I'm aware that the 7A29 loses some bandwidth with the variable control engaged, but it was the only way to make it fit for a risetime measurement using the graticule.

Be aware that in order to use an impulse to measure risetime, you have to know the impulse's characteristics. Knowing that, you can use deconvolution to work out the scopes' impulse response.

If the pulse is much shorter than the scope's response time, then the scope shows the integration of the area under the impulse. That's the principle that we used in school physics lessons to measure charge with a current meter. There you rapidly discharge the capacitor into a slow acting ballistic galvanometer, and measure the needle's peak deflection which occurs around a second later.

Informally, and in a hand-waving fashion, your scope would show the same response to a 1ps 10V impulse and a 0.1ps 100V impulse.

If, however, you can add a transmission line stub to your impulse generator, then the resulting step will be helpful in measuring the scope's risetime.

I occasionally wonder about buying a ballistic galvanometer "for old time's sake". Then I come to my senses and realise it would be a poor use of floorspace and my time.

Are there any application notes that talk about this? Be interested to read more. 

[tggzzz]

Got my hands on some 2 pF ceramic caps, so I gave the avalanche pulser another go, this time using Manhattan style construction. It works! There's still some optimizations to be done, such as getting some high quality 50 ohm resistors instead of paralleling a pair of 100 ohm resistors, and shortening leads some more. Then make it fit into a BNC project box. But, I'm happy with this prototype! [edit] yes, I'm aware that the 7A29 loses some bandwidth with the variable control engaged, but it was the only way to make it fit for a risetime measurement using the graticule.

Be aware that in order to use an impulse to measure risetime, you have to know the impulse's characteristics. Knowing that, you can use deconvolution to work out the scopes' impulse response.

If the pulse is much shorter than the scope's response time, then the scope shows the integration of the area under the impulse. That's the principle that we used in school physics lessons to measure charge with a current meter. There you rapidly discharge the capacitor into a slow acting ballistic galvanometer, and measure the needle's peak deflection which occurs around a second later.

Informally, and in a hand-waving fashion, your scope would show the same response to a 1ps 10V impulse and a 0.1ps 100V impulse.

If, however, you can add a transmission line stub to your impulse generator, then the resulting step will be helpful in measuring the scope's risetime.

I occasionally wonder about buying a ballistic galvanometer "for old time's sake". Then I come to my senses and realise it would be a poor use of floorspace and my time.

Are there any application notes that talk about this? Be interested to read more. 

No, I don't think it is app note material.

The ballistic galvo is school physics, but I couldn't find it in my remaining school textbook I suggest looking in an old physics textbook.

The convolution is basic signal/filter/system theory. Maybe https://allsignalprocessing.com/convolution-of-signals-why/
https://www.dspguide.com/ch6/2.htm might help.

[Specmaster]

Ah yes the hybrid tube / transistor circuits of the early 60s. Quite a bit of fun those. Ooh hello Mr Transistor, let me see if you are hot. Bzzt. Ouch! Been there 

Haha, hot in more ways then 1 eh 

That seems to a rather large potential across a small junction 

[beanflying]

For anyone who would like to try out Prusa Slicer with an Ender or CR-10 my profiles attached. This is the bed size and layouts, print speeds and accelerations. As I mentioned in a recent post you might need to tweak the retraction by a mm or two if you get stringing. Other than that the stock Slicer settings get it done well 25-40% infill and 3-6 layers depending on the strength required for newbies.

Also includes my settings for generic evilbay PLA and PETG which work but there is also Prusa's own settings in the software.

https://github.com/prusa3d/PrusaSlicer/releases

Fuki the 3DP PC keeper says Hi too 

[mnementh]

YOUR decision to only use a service to print items and never own a printer and I assume never use the shared one you have access to is YOUR option. It follows that then in no way make you a competent or practiced user of a well setup 3D printer and reading some 'manual' doesn't make you practiced or more competent in your use of one.

A well setup printer with a tweaked profile or two makes it a walk up insert card and print not the fiddle you keep go on with. Your version of your truth has no basis in fact with modern printers and the truth but you tried to justify it with a narrow case of a shared one as evidence that is likely poorly maintained caked with crud in the nozzle etc.

So stop attempting to be both an expert at setting up and using a printer when you apparently have little to no experience in doing so while dumping on personal ownership and use of one.

It is clear that I don't own one (and therefore have not twiddled configs); until very recently the only one I had access to was a joke suitable only for demonstrating principle. Hence I have made zero pretence to be an expert, and I resent your false statement to that effect.

However, your phrase "A well setup printer with a tweaked profile or two" reveals that fettling is indeed required. The next question is how much fettling? There I have to rely on watching experienced users of the local machine, and the amount of fettling the have to do to ensure it makes acceptable prints - and it is non-trivial. I have also seen many anecdotes to the effect that users of other machines do recognise that fettling is an issue.

I'm happy that you have found a printer that is suitable for your purposes. It could never be useful for my purposes, since I have found it necessary to use four radically different materials: brass, PLA, nylon, SLA.

Now, while I dearly like my vintage scopes and use them daily, I wouldn't recommend them to an infrequent user that doesn't want to spend time keeping them working - because too much fettling time is required. Similar considerations apply to 3d printer.

YMMV, of course. And that's just fine.

You just reinforced both bean's point and my own; the prime difference is the type of the machine. You essentially state that CROs are not professional tools anymore; they are hobbyist gear, just like the FDM printers bean and I have been proselytizing. And YOU ARE RIGHT. Anybody who NEEDS a scope for their job is NOT going to buy a CRO; they're going to buy new and that means DSO/MSO. CROs, learning tool value aside, really are a novelty or at best a tertiary reality check in any shop or lab that needs a scope.

CROs ARE A HOBBYIST TECHNOLOGY; the very nature of this thread is proof and validation of that fact and their value as such. So fucking what? 

This is what: The difference is you are HATING on hobbyist 3DP Technology FOR BEING hobbyist technology. THAT is just plain willful ignorance.

Those of us who've actually BOTHERED to get into the hobby, and KNOW SOMETHING ABOUT IT, repeatedly try to educate you... to demonstrate that the technology has matured hugely, that it is MUCH CLOSER to turn-key than even a few years ago... but you still stubbornly refuse to acknowledge even THAT.

You want a turnkey product? Fine... there are dozens of turnkey providers out there who will gladly take thousands of your hard-earned dollars and reward you by locking you into their overpriced name-brand cartridge supplies for more and more thousands of dollars over the life of the device, and you won't have to disturb a single grey cell learning something new. Pay enough, and it'll even come with a guy in a lab coat to fix your problems for you. 

But PLEASE stop bitching that hobbyist 3DP is hobbyist-grade. EVERYBODY HERE already knows that, and you just make yourself look like an ass for pointing it out at every opportunity. 

The rest of us will continue to enjoy the juicy, sweet fruits of our very modest time & money investment in hobbyist-grade 3DP. You can continue to suck on your sour grapes.

mnem
But PLEASE... do it quietly, in the privacy of your own mental space. Everybody else is sick of hearing about them.

[mnementh]

I think we should have an old fashioned Victorian style fist fight 

pfffft! Fuck them Queensberry Rules!!!

mnem
 

[worsthorse]

The Tektronix 106 is on the bench. A whole different animal than the 114. Vacuum tubes (six of 'em). Ceramic terminal strips. An internal fan. Some very dense point-to-point component wiring:



I hope I don't have to replace anything in there. That's the range switch and multiplier. Here it is from the outside. Dig the crazy GR connectors.



Still has the roll of silver solder for working on the ceramic terminal strips.



And because we haven't had any in a while, some fan pron:



Here's what it looks like inside:





Here's the two output boards. Unfortunately, there is a bad electrolytic on both of them:



On inspection, I found at least one other bad electrolytic, this one on a ceramic terminal strip. It is the blackened cap in this photo. It may have damaged the 2W resistor sitting under it.



I did power it up and it puts a proper square wave out, the fan whirs, and the range, symmetry, and amplitude controls work. Given the bad caps, I didn't want to push my luck, so I will replace them before putting power on it again.

I hope I don't have to replace any of the power supply capacitors because it basically means taking the damn thing apart as they are mostly under the ceramic terminal strips. It looks like they were installed first, wired to the ceramic strips and then everything else was wired in on top of them. 

[Cubdriver]

Nice!!  The 106 and a 191 were my second encounter with those GenRad connectors.  My first had been an hour or two earlier that day, at the TRW swap meet when I talked to a vendor who had a bunch he was selling that had come from a shop that closed down.  I thought they were a very clever design, but of course never having encountered them before I saw no need to buy any.  That afternoon at Apex I bought the Tek generators, then didn't manage to again cross paths with the guy who had the connectors for about a year.

The generators are still in the box I shipped them home from CA in; haven't gotten to unpacking them.  I'm waaaaay behind!



-Pat

[med6753]

I want one! Right now I've got other priorities but I'm going to keep watching Ebay. If a Type 106 pops up for under the typical price of $100+ USD I'll jump on it.

Typically those large filter cap cans in older vacuum tube Tek gear last forever and don't go bad. I think once you replace that fubar cap the unit will operate properly.