Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

I dunno about anyone else, but in my head I reached about 28 and stopped.  Sadly the calendar has not...  (And I often miss the passage of the entire decade from 2000-2010 - the 90s do NOT feel like they were thirty years ago, and there's no way in hell that more than two decades have passed since all the Y2k craziness.)

-Pat

Quite agree, it seemed to me that the school years just seemed to drag along so slowly as if time had been suspended, but since leaving school and entering the work place, time has been passing too quickly that I keep looking for the brakes, but there aren't any 

My theory on that is that there are several things at play.

The first is simply that as we get older, each passing year equates to a smaller percentage of the time we've been here - at the age of ten, a year is a tenth of our life; at 25 it's 0.04; by 35 it has dropped to 0.029 - each less than the last.

The other, and more prominent thing IMO is that when we're school aged, there are bigger milestones in life - using the US for example as it's what I'm familiar with, there is the start of school in September, at which point as a kid you begin looking forward to Halloween in October, then on to Thanksgiving in November, then Christmas/New Years break in December.  There (at least were) a few days off some time in Februaryish for a 'winter break', then comes Easter and finally the end of the school year in June, followed by summer vacation.  A series of very distinct milestones that are big deals as a kid and at the time, seem to take forever to come, and clearly mark the passage of time.  Now as an adult, I get up and go to work.  The year starts cold and snowy with short days and long nights and occasionally snow to shovel.  I get up and go to work.  The days begin to grow longer, the nights shorter and the snow melts.  Wow, Easter already...  I get up and go to work.  The shift in night/dark continues and it gets warm then hot out.  I get up and go to work, then cut grass and do yard work.  Then the daylight shift goes the other way and it gets cooler and I clean up leaves.  I get up and go to work.  Holy crap, how is it Thanksgiving next week?  I could have sworn it was Easter a month ago, and Halloween slipped past without me noticing!  I get up and go to work.  Wow, Christmas already?  Thanksgiving seemed like last friggin' week, FFS!!  And now it's time to remember to write a new date on things.  Where did the past year go?  It all merges into a big blur that moves ever faster, like rolling down a long hill.  Not saying it can't be a fun ride, just that it keeps getting faster.

-Pat

Here's another thing that I have never quite been able to grasp either, if I'm driving somewhere, let's say I'm driving from Chelmsford (home), to Lakenheath, something that I've done many times, why does it always without fail seem to be far quicker driving back home again afterwards 

Maybe you don't stop for a cup of coffee on the way back!

Nope, I never stop for coffee either on the way there either, it's exactly the same route both ways as well. Never stop for fuel either, as I always ensure that I have at least half a tankful before setting off.

[THDplusN_bad]

Tek showed a complete Oscilloscope washing station in one of their publications back in the day.

Yes, I have found that version of the mentioned note, too - as an attachment in this forum 

https://eevblog.com/forum/projects/how-to-wash-your-oscilloscope!/?action=dlattach;attach=240858

[TERRA Operative]

I just stuck the front and rear nicotine stained panels from the TDS620B through the dishwasher, they came up beautifully.

So now the entire scope is sitting on my desk in it's component pieces, some will be washed by hand (The processor and acquisition boards are in the disk rack now) and some will be sent through the dishwasher.

Then after the cigarette stank is gone, I'll start troubleshooting the PSU. I really need to finish my PSU test jig soon... Got 3 PSU's to fix now.

[Specmaster]

There is quite a bit of research on this, the last I remember reading was it's related to the way we form memories, and how new vs repeated experiences are laid down. Basically if you do the same thing a lot, ie get a job and commute to work, shuffle papers all day, time passes much faster than if you're doing something that's new to you, interestingly in retrospect rather than real time, which seems to slow down when you get bored doing repetitive tasks.
I'm not going to try and find the article, it was in the New Scientist, probably at least 15 years ago. There'll be much more recent research to read than that.

That does make perfect sense, given that with the insanity of the past two years on a day to day basis time has slogged, but overall it does not seem possible that two years have gone by already.

-Pat

I have seen some research that has shown we have an internal brain clock, and as you age it slows, thus the world around you appears to go faster. Falling off your bicycle etc can also temporarily speed up your clock so the world appears to go slower as you fall.

We certainly do, but that it slows? Nope, I haven't used an alarm clock in decades, I tell my brain how long I want to sleep, and it wakes on time. It's accurate to within about +/-5 minutes per hour.

That is what I do, but I find that repeating the process of telling my brain over and over as I drop to sleep improves the time keeping function, but occasionally it fails, and I oversleep so its not infallible.

[Zucca]

sumtin TEA.

Only checked CV. Seems that I do get some voltage drop - 5V selected, 4.974 V at the output terminal.

Also checked with about 66 V, same result. Should be sufficient for checking pinball coils.
Maybe a bit overkill.

Boss told me that he did want to see some FPGA related results today. Need to get my FPGA test workstation up and running and install a &%$%&$ Linux.

*sigh*
What does Vitis AI run on again ? ...

sexy

[Cerebus]

Nope, I never stop for coffee either on the way there either, it's exactly the same route both ways as well. Never stop for fuel either, as I always ensure that I have at least half a tankful before setting off.

You don't stop to water and feed your donkey horse? That's cruel that is! 

[Zucca]

&%$%&$ Linux.

What do you think about Arch Linux?
It seems a good horse to me.

[mnementh]

working on my relaxation room ...

I played Asteroids until I was wasted when I was a little one.
If I become stupid and/or rich, I want one in my basement.

If there ever was a game that got me hooked (in my early youth or childhood), it was the tank game with the green vector graphics.

Battlezone. That and Asteroids got me hooked too!

https://en.wikipedia.org/wiki/Battlezone_(1980_video_game)

Asteroids, then Tempest, then Star Wars. Bitmap games: Ummm... Moon Patrol, Centipede, Galaga and Ms PacMan. One of the Dave & Busters type grownup arcades I went to in Toronto had Galaga on a 120" LED signage display... that was a hewt.

mnem
*catching up-ily*

[Specmaster]

Nope, I never stop for coffee either on the way there either, it's exactly the same route both ways as well. Never stop for fuel either, as I always ensure that I have at least half a tankful before setting off.

You don't stop to water and feed your donkey horse? That's cruel that is! 

Nah, I do all of that before I go, my horse is a true horse that only need infrequent stops for energy, not like its modern electric counterpart  that has to keep making stops to top up its bleeding batteries. It would be cruel to push on thinking that you can always find a place to stop and top up and then discover that you can't do that and then have to shoot the poor horse, now that is real cruelty is that 

[mnementh]

Stepdrills are much better than standard twist drills for diecast boxes and thin sheet materials. 12.7mm is of course 1/2 inch.....

And bugger all use for anything else. I'm deeply suspicious of step drills, all that rotating mass, all that stick-out, having to have lots of free space the other side of the workpiece for all the smaller steps waiting to foul on your vice or another part of the workpiece. I generally use stub drills whenever I can and I'm much happier seeing perhaps 50mm of bit sticking out of the collet rather than 6 inches of heavy rotating tool. Also I've no idea how you would sharpen a step drill. I think the thing that convinces me more than anything else is that I've never seen one in any proper machinists workshop or the catalogues of suppliers like Dormer who sell drills to proper machinists. That I've never seen a set for more than £15 for three does little to convince me of their quality. Whether it's fair or not, step drills have always smacked of amateur hour to me.

Anyway, any hole you want from 0.3mm to 8mm in 0.1 mm steps I've got covered. Well, I've got covered with twist drills; I can't pretend to have even a fraction of the reamers required to call those accurate holes. It's just when you get any bigger than 8.0mm (in metal) that I have to reach for odd sizes bought for particular jobs that required them.

Better for big holes in sheet metal and thin materials are Q.Max punches (other brands are available, as they say on the BBC), of which I've had a selection over the years. They will work on die cast boxes but frankly it's a bit toward the top end of their capabilities (official capacity 2mm of aluminium) but that hasn't stopped me over the years - a little bit of lube can cover a multitude of sins. Where they really excel is non-round holes. Q.Max used to make punches for D connectors but they seem to have been discontinued. Ditto those awkward holes with a non-rotation flat on one side (which is what I could really have done with for the 12.7mm hole). They also have the advantage that if one is less than precise at getting one's holes in the right place one can make the pilot hole a fraction oversize and align the die precisely while initially tightening it; this can work the other way, because the pilot hole needs clearance one has to be careful not to wander off centre when fitting up the punch.   

Dormer sell step drills, "reassuring expensive" at "£114
https://www.cromwell.co.uk/shop/cutting-tools/sheet-and-tube-drills/series-g314-hss-conical-drill-step-drill-metric-2mm-increments-/f/68205

Problem with most twist drills is they are not ground for thin materials and tend to grab.
"proper" machine shops have wnough work to sock all sizes and grinds of drill and / or equipment and skills to re-grind for a particular application.

Step drills just need a couple of rubs with a flat diamond file on the flat face to sharpen them.

Yeah... the nature of how step drills are usually used means that sharpening doesn't need to happen very often. When they are applicable to a job, step drills are a godsend; and generally cheap enough to treat as a consumable supply.



Of course, I still have these rather disreputable-looking examples to fall back on for when I have to get it just right... they may be old & ugly, but they still work as long as you're willing to put in the work. 

mnem
 

[mansaxel]

Of course, I still have these rather disreputable-looking examples

A hand reamer is a thing of beauty. I really should get one, up to 12,7mm would do nicely.  I have this little project with an acoustic guitar, that needs a pickup. The noveau-classique way to fit the phone jack is to replace the shoulder strap knob on the body with a special 1/4" jack that not only serves as output but also as knob. (The phone jack also serves as power switch to the preamp in the pickup, if it's active. Shorting ring and sleeve grounds the battery circuit and powers the preamp.)

[mnementh]

   

Those are plugs for loudspeakers, to be exact "Lautsprecherstecker nach DIN 41529" and they are horrible!
Burn them with fire!

Not good enough. Anything short of full conversion to monatomic plasma is insufficient.

Perhaps a bit extreme ... but quite understandable and I support your freedom to do so.  (Please post pics if you do  )

As much as they appear to be loathed around here (I was always pretty "meh..."      about them, myself), they are still commonly used as power connectors for small LED lighting, particularly desk lamps and such made by IKEA. Worth keeping (stow them in a hazmat baggie if you must ) in case you need to make a extension or repair a borked wire.

mnem
 

[mnementh]

Switchcraft are "keepers of the faith", not product evolvers

I think everybody who could do so, stopped using Switchcraft the minute Neutrik arrived. If I had a penny for every cable mounting Switchcraft XLR that I lost the stupid little grubscrew from while assembling it and had to scramble around on hands and knees finding it, I'd put them all as shrapnel in a bomb casing and send it to the bastard who designed them.

And don't forget the other one... that little bastard always falls out while you're soldering, and you don't notice it missing until you go to assemble. 

And that one is effing left-hand thread, so you aren't gonna get a replacement from the local hardware store.

mnem
 

[mnementh]

...The most famous photo of a chair probably ever printed is of a Jacobsen chair:



One can see a very "Danish" æsthetic in both. (Ms Keiler's æsthetic is entirely British  )

Mmmmmmmm... Art Appreciation. 

mnem
*slurrrrrrrrp*

[Kosmic]

I got a new Keithley brown box recently. Keithley 617 electrometer. I don't really need it but have a soft spot for electrometers. It's coming from our federal government auction site.



The screw beside the COM terminal indicate that this is one of the later model (the screw is holding a fuse).


The input circuitry is isolated on a mezzanine board and the digital and voltage source are on the main board at the bottom.


This is where the magic happen, Hand pick JFET, 250G\$\Omega\$ resistor, low leakage reed relays mounted on PTFE standoffs.


In the end I was lucky, the meter is working fine and I didn't paid that much.

[mnementh]

I dunno about anyone else, but in my head I reached about 28 and stopped.  Sadly the calendar has not...  (And I often miss the passage of the entire decade from 2000-2010 - the 90s do NOT feel like they were thirty years ago, and there's no way in hell that more than two decades have passed since all the Y2k craziness.)

-Pat

Quite agree, it seemed to me that the school years just seemed to drag along so slowly as if time had been suspended, but since leaving school and entering the work place, time has been passing too quickly that I keep looking for the brakes, but there aren't any 

My theory on that is that there are several things at play.

The first is simply that as we get older, each passing year equates to a smaller percentage of the time we've been here - at the age of ten, a year is a tenth of our life; at 25 it's 0.04; by 35 it has dropped to 0.029 - each less than the last.

The other, and more prominent thing IMO is that when we're school aged, there are bigger milestones in life - using the US for example as it's what I'm familiar with, there is the start of school in September, at which point as a kid you begin looking forward to Halloween in October, then on to Thanksgiving in November, then Christmas/New Years break in December.  There (at least were) a few days off some time in Februaryish for a 'winter break', then comes Easter and finally the end of the school year in June, followed by summer vacation.  A series of very distinct milestones that are big deals as a kid and at the time, seem to take forever to come, and clearly mark the passage of time.  Now as an adult, I get up and go to work.  The year starts cold and snowy with short days and long nights and occasionally snow to shovel.  I get up and go to work.  The days begin to grow longer, the nights shorter and the snow melts.  Wow, Easter already...  I get up and go to work.  The shift in night/dark continues and it gets warm then hot out.  I get up and go to work, then cut grass and do yard work.  Then the daylight shift goes the other way and it gets cooler and I clean up leaves.  I get up and go to work.  Holy crap, how is it Thanksgiving next week?  I could have sworn it was Easter a month ago, and Halloween slipped past without me noticing!  I get up and go to work.  Wow, Christmas already?  Thanksgiving seemed like last friggin' week, FFS!!  And now it's time to remember to write a new date on things.  Where did the past year go?  It all merges into a big blur that moves ever faster, like rolling down a long hill.  Not saying it can't be a fun ride, just that it keeps getting faster.

-Pat

This has been my life since parenthood struck the dwagon household... I swear it was just yesterday that I was holding that wiggly little boi in my arms in the hospital; now there's two of them and we're outnumbered. 

The last few days tho, I've been acutely aware of the passage of time... seems I really was interested in the job at hand.

mnem
A little wrangler is born;
I see him squirming in the saddle all wet and warm.
He's such a changeable form; in his very first year...

[m k]

Oh boy life' crap ! Look what it's doing to me !

A guy is selling a couple very decent looking old glowing Tek scopes, for dirt cheap !

A type 317M for 15 Euros

https://www.leboncoin.fr/equipements_industriels/2111398794.htm

and a 535A (somehow titled as a type 517A ?!  ) for 20 Euros !!

https://www.leboncoin.fr/equipements_industriels/2111397713.htm


But local pickup only ! He lives in the far south east of France light years away from me ! 

Actually he has been trying to sell these for at least 6 if not 12 months can't remember, must at least the third time he lists them.
The original price was very fair to being with, like 60 Euros maybe for the big type 535A or something, but looks he is so stubborn on local pickup , he keeps dropping the price now to a misery, instead of making the effort to ship  !
I guess someone half-local to him might now find the trip worthwhile.... but that can't be me sadly ! 

Lowest price for Helsinki - Nice was said to be 22€, then what.
(cargo bay?)

Some commuting, language style hand gestures and back to the airport but can you send ahead your own stuff?
I presume luggage scope must be dismantled.

[m k]

I had to contact Ebay directly today. I still haven't seen the refund for the Tek 7B92 plug-in. The seller told me via Ebay messages that he processed the refund. According to Ebay he did not. Fucking bastard. So Ebay is going after his sorry arse and getting me the refund.

Seller  puuri_surplus. Stay away.

Well that didn't take long. Msg from Ebay that a full refund is on the way. Turns out the seller thought he had fully processed the refund. Yea, right. Ebay set him straight. He sent me a msg apologizing for the mix up. Just consider yourself lucky that I don't post negative feedback. 

You can't (at least not on German ebay). As soon as you raise any case / refund etc. the item is no longer shown in your bought items and there's no possibility to give feedback. It's another one of ebays methods to try to convince us that all runs smoothly at ebay and to protect their cash-cow.

McBryce.

Same here and I use ebay.com, maybe it's purely a location thing.

BTW,
sorry about the earlier inconvenience.

[mnementh]

   ...Of course, I still have these rather disreputable-looking examples

A hand reamer is a thing of beauty. I really should get one, up to 12,7mm would do nicely.  I have this little project with an acoustic guitar, that needs a pickup. The noveau-classique way to fit the phone jack is to replace the shoulder strap knob on the body with a special 1/4" jack that not only serves as output but also as knob. (The phone jack also serves as power switch to the preamp in the pickup, if it's active. Shorting ring and sleeve grounds the battery circuit and powers the preamp.)

Yeah, I've had that one since I was my son's age, originally for custom panels on RC gear and car bodies... Radio Shack maybe? Bought more than a few of those nibblers from them over the decades as well...

mnem
 

[Kosmic]

I got a new Keithley brown box recently. Keithley 617 electrometer. I don't really need it but have a soft spot for electrometers. It's coming from our federal government auction site.

So, something a little less obvious you can do with those electrometers, is using them as a buffer for a meter with higher resolution but lower input impedance. Electrometers, normally have a really high input impendence (­>200T\$\Omega\$ in the case of the Keithley 617), wide voltage range (200V for the 617) and the Preamp output is normally accessible. For the 617 the preamp output is supposed to be +-5ppm off.

A little example, trying to measure the output of a voltage divider. 1KV is feed in the voltage divider and 100V should be measured on the output.


The 1KV source measured directly.


For comparison, the 34401a connected directly to the output of the voltage divider. The 10M\$\Omega\$ impedance of the meter is loading the divider and voltage is dropping a bit.


I'm impress with this old ESI voltage divider. Still working really well.

[Cerebus]

Of course, I still have these rather disreputable-looking examples

A hand reamer is a thing of beauty. I really should get one, up to 12,7mm would do nicely.  I have this little project with an acoustic guitar, that needs a pickup. The noveau-classique way to fit the phone jack is to replace the shoulder strap knob on the body with a special 1/4" jack that not only serves as output but also as knob. (The phone jack also serves as power switch to the preamp in the pickup, if it's active. Shorting ring and sleeve grounds the battery circuit and powers the preamp.)

A thing of beauty when used to deliberately make conical holes, a horror when used to make holes that ought to be cylindrical by their nature.

This little babe came from Luthiers Mercantile International (www.lmii.com). It's set to exactly the angle (3º) that's used as standard for end pins and for string retaining pins (there's also a 5º standard as well, but 3º is the commonest). Note that it has teeth only on one face, the other is smooth and that feature is crucial to maintaining concentricity when reaming by hand. This is the 'economy' version that comes in at a mere $73 at current prices, the posh German one they sell is $170. Mine has been used a fair bit, I've never sharpened it but it's still so sharp that I could cut myself on it. You don't actually ream out the hole, you just turn it a few times under very light pressure until the entrance hole magically becomes the right diameter and some sawdust dribbles out the far side. Presumably the $170 German version is so sharp that it needs its own special holder so that you don't inadvertently lean the edge on something like the tabletop and cut through it.



The holes it cuts are so precise that I've never had to glue an end pin; they are smooth and perfectly concentric with the [lathe cut] pins. A light tap with a leather faced mallet and the peg is in there for good.

However, you won't need one for an end pin jack, all the ones I've encountered go into a straight 1/2" hole (L.R.Baggs and impersonators) or a straight 1/2" hole that is then tapped to a 9/16"–12 thread (Switchcraft, need I say more?). (Standard end pins are 1/3" at the fat end.) So a standard 1/2" spur lip drill is going to be your weapon of choice, along with some very careful clamping and fixturing.

If your pillar drill is capable of being reversed (to overhang the edge of a bench) then some judiciously shaped clamping blocks (with something soft like felt, foam or leather on the faces) and some wide carpenter's clamps are the way to go. That's how I've always drilled out the holes for end pins. Needless to say, only clamp with any force on the end block with only the lightest clamping force on the very edges of the guitar itself to stabilise things and none at all on the unsupported soundboard itself. (Soundboards seem quite firm when they are on the guitar but they are immensely fragile things and will crack along the grain with only the slightest persuasion.)

I've had the advantage that when doing it I've only had a body to deal with, before the neck is glued on - you might have problems finding the height to fit a whole guitar, neck and all, in between the floor and the drill, with something at the right height to clamp the body to.

There's something very unnerving about taking a 1/2" drill bit to the bottom of a mostly finished guitar. Taking one to a completely finished guitar would be nail biting. Definitely the kind of job that you spend a couple of days rehearsing inside your head before eventually going for it.

[Zucca]

So, something a little less obvious you can do with those electrometers, is using them as a buffer for a meter with higher resolution but lower input impedance

Very interesting, I used to have a 617 and a 220 but then I sell everything with all my Triax jazz cables.
I can't remember the bandwidth of the preamp...

[Kosmic]

So, something a little less obvious you can do with those electrometers, is using them as a buffer for a meter with higher resolution but lower input impedance

Very interesting, I used to have a 617 and a 220 but then I sell everything with all my Triax jazz cables.
I can't remember the bandwidth of the preamp...

the -3dB point is at 100kHz.

[Andrew_Debbie]

A few days back, there were some posts about parts storage.   

I use inexpensive "Parkside" organizers from Lidl.   Right now, this week Lidl have these small ones for £3.99 each. 



The large ones were slightly more, but still cheap.   Not currently in UK stores, but maybe they will return.   I bought 3 not knowing if they were any good.  Should have gotten at least 5.




Coilcraft order going into the small box:   I bought direct. Couldn't find an in-stock distributer.

[DC1MC]

&%$%&$ Linux.

What do you think about Arch Linux?
It seems a good horse to me.

You want to suffer, or you want the job done, Xilinx clearly states on which distribution their tools runs, install Ubuntu.