Test Equipment Anonymous (TEA) group therapy thread

[srb1954]

Still, it's cool to know there is such a thing as " Neper " meter !

They've been out of use for a long time. When I was working as an outside broadcast engineer, here in Germany, the guys from Deutsche Bundespost drove up with their little Mercedes van to wherever we were broadcasting from, parked next to our O/B van and handed us the ends of a twisted pair as the audio line back to our Cologne studios.  Their level meters in this van were calibrated in Neper. First and last time I've ever seen one in real life. That was in the late 1970s.

Nepers are for old-time engineers who think the younger generation of engineers has it far too easy these days with their simple base 10 counting system.

The more hard-core of these old-timers are so irrational they cut some of their fingers off so they can count using 2.71828... digits 

[THDplusN_bad]

I have a birthday with a zero at the end this week and had lunch with the family today. Twin sister (slightly older) was there of course.
Gifts were received 
The Cheese was from Sis and brother in law as part of a Fortnum and Mason Hamper
Facom and Knipex were from my brother (he needed a clue and I'd seen both on here). I was only expecting one or the other.
R&S was from SWMBO 
I'm well fed and very happy. I might just have a beer from the hamper.

Those are nice birthday gifts for sure. I am confident you will like the KNIPEX. I use my set (I have a large and a small one) at least twice a week. 

Cheers,

THDplusN_bad

[McBryce]

You don't know what it installs.
We've lost control when MFM controller was left behind.

BTW,
Palmtronic and RAD results 1, DEG is a bit under, w/o tan() it's a bit over and w/o cos() it's 1.

BTW2,
my poor P-touch 500 doesn't even have a display.

I do because I've dumped and inspected the entire contents of the virtual drive and also connected it to a Linux machine where I can fully monitor what the USB connection is doing. It doesn't install anything.

McBryce.

They(them) will secretly inject those legit files.
And export bogus empty space.

Your disk tracks have sectors and sectors and those other sectors are reallocation zones.
So when sector is bad it is reallocated and LBA doesn't change but physical place is different.

The disk can also reallocate for what ever secret purposes it want.
It can also use unused space how ever it see fit.

So when disk is nearly full they say it has troubles but why.
Obviously because it must relocate all the spy stuff.

So that's how they did it in the last century! Neither my PC nor the label printer has disks or sectors. They're completely solid state. Or are you telling me that you don't use USB sticks for fear that the manufacturer will install spyware? How can you use a PC at all with that view?

McBryce.

[PA0PBZ]

Neither my PC nor the label printer has disks or sectors. They're completely solid state.

 

[ch_scr]

Don't know how you lot do it, but my colleague just asked me, he has spotted two dirt cheap Brother PT1230 USB label printers and he wanted to know if I might want one of them...

[SeanB]

Shahriar could have saved himself a lot of work by just going out and buying a Fluke 8920A or 8921A, with the GPIB option, and writing a suitable user interface for his PC using Labview or similar. This would have provided all the functionality of his custom modifications without having to even open the case of the instrument.

Would not be Shariar if he did that, he is very much into having both good looking, and esoteric, test and measurement equipment.

[SeanB]

Don't know how you lot do it, but my colleague just asked me, he has spotted two dirt cheap Brother PT1230 USB label printers and he wanted to know if I might want one of them...

I could do with one, went to use mine, and........ Energiser.........

Ah well, at least the Zebra thermal transfer printer works, though thanks to Glabel breaking with some recent kernel updates, I am stuck with using the Zebra software under Windows to use it. But i do at least know how to use it reasonably well, and the printer itself was free, thanks to them being upgraded with newer faster ones.

[Saskia]

congratulations, Robert !
May you enjoy many more years, hopefully in splendid health !

[BU508A]

Don't know how you lot do it, but my colleague just asked me, he has spotted two dirt cheap Brother PT1230 USB label printers and he wanted to know if I might want one of them...

And your answer was for sure "Yes!" ... 

[Robert763]

The 3400x  (and digital 3403x) are completly different beasts from a standard VTVM. They use thermal converters so are proper RMS by design. No calculations or conversions. They are correct whatever the wavefom including high frequency components up to 20MHz.  The Fluke 892x series are similar.

Shahriar could have saved himself a lot of work by just going out and buying a Fluke 8920A or 8921A, with the GPIB option, and writing a suitable user interface for his PC using Labview or similar. This would have provided all the functionality of his custom modifications without having to even open the case of the instrument.

For such a simple read only application you don't need a full GPIB interface and Labview. A 5V PIC can handle a direct connection to single GPIB port with just pull-ups.

[Saskia]

Don't know how you lot do it, but my colleague just asked me, he has spotted two dirt cheap Brother PT1230 USB label printers and he wanted to know if I might want one of them...

And your answer was for sure "Yes!" ... 

what else ... I think I paid about 30 for my dymo label printer ...

[Peter_O]

I plan to fiddle around with linear power supplies in the near future and looked for a variable transformer for that purpose.

Most economic way would have been to buy a galvanic separated 240V variac and have all voltages in one box.

But that would not be TEA style.   

So I found this beautiful Ruhrstrat 0-25V / 10A one, built 1981.



The Phywe PSUs für schools (https://www.ebay.de/itm/154107811891) would have been cheaper. But they miss the meters and are ugly in general.

Ruhstrat is a very old company in germany, today they seem to be more into industrial solutions. https://ruhstrat.com/?lang=en

My AC/DC resistive load  is able to handle 8A max. I didn't want to stress that buddy too much, same for the PSU, so I leave it with 5A. No smoke, no smell. Everything fine.



Meters show more than reasonable values.
And I tested the "Dual" function of the Siglent 3055 along the way.

Somebody change the fixed power chord and spent some cable ties, otherwise it seems untouched.

[ch_scr]

I plan to fiddle around with linear power supplies in the near future and looked for a variable transformer for that purpose.

Most economic way would have been to buy a galvanic separated 240V variac and have all voltages in one box.

But that would not be TEA style.   

So I found this beautiful Ruhrstrat 0-25V / 10A one, built 1981.
(....)

As beautiful as it is inside, I probably would change that Selenium rectifier. Aside from sparing you the Stench when it cooks off, it would also lower output impedance and increase max voltage a bit, while lowering waste heat inside the case...

[VK5RC]

The Signal Path has a new video on the HP 3400b

Lovely bits of gear, I have a couple of working 3400a (a model goes to 10MHz, b to 20) with a spare set of matched thermocouples - they are specifically mentioned in my Will 🤣

[Robert763]

I plan to fiddle around with linear power supplies in the near future and looked for a variable transformer for that purpose.

Most economic way would have been to buy a galvanic separated 240V variac and have all voltages in one box.

But that would not be TEA style.   

So I found this beautiful Ruhrstrat 0-25V / 10A one, built 1981.



The Phywe PSUs für schools (https://www.ebay.de/itm/154107811891) would have been cheaper. But they miss the meters and are ugly in general.

Ruhstrat is a very old company in germany, today they seem to be more into industrial solutions. https://ruhstrat.com/?lang=en

My AC/DC resistive load  is able to handle 8A max. I didn't want to stress that buddy too much, same for the PSU, so I leave it with 5A. No smoke, no smell. Everything fine.


Meters show more than reasonable values.
And I tested the "Dual" function of the Siglent 3055 along the way.

Somebody change the fixed power chord and spent some cable ties, otherwise it seems untouched.

I can't find a datasheet to b sure, but that looks like a Selenium rectifier. I'd be tempted to replace it with a 25 A silicon bridge rectifier. RIFA stink is insignificant compared to a Se rectifier letting the smoke out.

Had a "honey do" from SWMBO when typing and ch_scr beat me to it. A R&S spectrum analyser got SWMDO lots of honey do points 
I would additionally suggest adding a C13 outlet to the back This will provide 0-220V. Only low current though. I suggest fusing at no more than 1 Amp.

[Peter_O]

I plan to fiddle around with linear power supplies in the near future and looked for a variable transformer for that purpose.

Most economic way would have been to buy a galvanic separated 240V variac and have all voltages in one box.

But that would not be TEA style.   

So I found this beautiful Ruhrstrat 0-25V / 10A one, built 1981.
(....)

As beautiful as it is inside, I probably would change that Selenium rectifier. Aside from sparing you the Stench when it cooks off, it would also lower output impedance and increase max voltage a bit, while lowering waste heat inside the case...

That's a good advice, thx.
Would be more than easy to change, it's plenty of space. And the museum piece could stay unconnected.

So for now I should better include a silicon rectifier into the external setup than using this old inside one.
Luckily a pack of six 25A silicon bridge rectifiers has just arrived.  ;-)

Are these guys going to fail with age? Or should I just be careful to stay within current limits?

[Robert763]

They do seem to fail with thermal cycling. I think the seals fail and let moisture in. Cheap ones relied on just the paint for sealing. Tht one may be better.
Using a silicon has the advantage for linear PSU design use that the output will be closer to what you will get in a final design.

[Vince]

OK I am back from the offcie supplies store, got a tape printer.

I got fooled, stupid me... I checked the web site of that store thinking they wold have everything in stock... but nope.
The cheaper printers I was targeting, around 30/35 Euros, had to be ordered ! No stock in the store !   
I didn't want to wait, I want some labeling action right now, not in 3 or 5 days.

So out with the Brother D210... instead I got, for 20 Euros more, 55 Euros total. a Brother D400.

Thermal transfer on laminated tape like the D210, so it's good, but it looks much better. Hated the black and faux carbon fiber treatment of the D210 
D400 is white, looks so much better, more appeasing to the eye, and brightens up the lab.
Also has a better LCD screen so you can better see what the label will look like.
Also has a wider form factor, which allow for a better keyboard, with more keys, more intuitive to use.
Proper intuitive scroll down menu system, navigation keys and Esc/OK button cluster at the right, it's a joy to use, it's like a little baby computer of back in the day, an early word processing machine or something.
K/B is rubbery, feels nice to the touch, quiet to use, lovely.
Good build quality.
Also can do wider tapes as well, not just 6/9/12mm. It can also do 18mm ! It's quite big... comes with an 18mm tape, so bought 12 and 9mm tapes to make sure I could get something that works for the drawer fronts.
However not yet expensive enough to enjoy a USB connector to download custom graphics, oh well.... was not really an essential feature was it 
Does have lots of built-in icons/ cliparts though, including a dozen EE related ones believe it or not... there are ground and earth symbols, AC, DC, filament lamp, fuse, stuff like that.
Lots of nice looking fonts too, 13 total IIRC.

It's really a lovely bit of kit, I am very happy I bought it, worth the money.
I see it as an investment... it's gear, that I need and will be useful.. it's not like I wasted 55 Euros on petrol to drive the car around aimlessly, or to buy alcohol or cigarettes or shit like that 

Obviously I would prefer to be like some here, that get printers for free ! Failing that, I am OK coughing 55 Euros for that one, it's good vale for money to me.

OK so let's get printing then ! 



EDIT : looks like the forum is having trouble with the pic thumbnails... the one for the first pic depicts a picture I posted yesterday !    But if you click on it, you do get the correct picture... it's only the thumbnail itself that is corrupt.

EDIT #2 ;  I spoke too soon !  I reloaded the page and now BOTH the thumbnail AND the full size pic are corrupt  ?! 

EDIT #3 : I re-uploaded the troublesome pic... seems to work now, the forum behaves... for how long I don't know, crossing fingers !

[xrunner]

You can save tape by typing in more than one label title in at a time. Like the "FUSES" label. Type it in and then add more label titles like this -

FUSES        RESISTORS        CAPACITORS

Put spaces between words (maybe 8 - 10 spaces) and then print it all out at once. Then cut between the label titles with scissors. Then you won't have all that waste at the front and back of each label.

There is a way to configure the thing to help in this regard but I never remember how. 

[TERRA Operative]

I use continuous printing or words to that effect in the Brother PC software to avoid the leading and trailing waste.

Also, for that bug with the posting images display corruption, it is a known thing (I thought it was resolved?) AFAIK the easy work around is to not use the first slot when uploading images, start from the second slot and then upload as usual.

[tggzzz]

You can save tape by typing in more than one label title in at a time. Like the "FUSES" label. Type it in and then add more label titles like this -

I save tape by using a small font and two lines. Has the virtue of getting more characters on the limited space of a small drawer.

I expect your technique could be combined with it.

[Neomys Sapiens]

I plan to fiddle around with linear power supplies in the near future and looked for a variable transformer for that purpose.

Most economic way would have been to buy a galvanic separated 240V variac and have all voltages in one box.

But that would not be TEA style.   

So I found this beautiful Ruhrstrat 0-25V / 10A one, built 1981.
(....)

As beautiful as it is inside, I probably would change that Selenium rectifier. Aside from sparing you the Stench when it cooks off, it would also lower output impedance and increase max voltage a bit, while lowering waste heat inside the case...

Gleich riecht er!

[TERRA Operative]

Oops, I did it again baby. Another TDS620B is on its way to me to get a spit shine and resell.
This one looks a bit mouldy, or something, so it sold for a good price. It'll be a reasonable earner once it's cleaned up and tweaked a little for resale.

[Saskia]

I plan to fiddle around with linear power supplies in the near future and looked for a variable transformer for that purpose.

Most economic way would have been to buy a galvanic separated 240V variac and have all voltages in one box.

But that would not be TEA style.   

So I found this beautiful Ruhrstrat 0-25V / 10A one, built 1981.
(....)

As beautiful as it is inside, I probably would change that Selenium rectifier. Aside from sparing you the Stench when it cooks off, it would also lower output impedance and increase max voltage a bit, while lowering waste heat inside the case...

Gleich riecht er!

https://www.science.org/content/blog-post/things-i-won-t-work-chalcogen-polyazides

[med6753]

Pat, I tried to verify that hot spot you are seeing in the A Sweep/Trigger circuit but mine is wired differently. This is an early S/N with a detachable line cord. I assume yours is probably a later S/N with a fixed line cord like my other two with the HV issues. Later this week I'm pulling out the one that still has the 5642 HV rectifiers in it to verify that the HV transformer is FUBAR. At that time I'll look and see if it's the same as yours and if yes I'll check to see if the same result as you are seeing.