Test Equipment Anonymous (TEA) group therapy thread

[Brumby]

You have an amplifier/detector?  Mine is an attenuator/detector.  Even then, some of the detections I have encountered have bent the needle.  Hate to think what would happen to the front end of an amplifier.

[mnementh]

Yeah, welll... you never know what you're gonna get on AliEx. I'm lucky it came in Engrish. 

In Other Nudes...



Mmmmmmm... tasty.


mnem
*Losing the Battle of Leftovers Plateau*

[bitseeker]

Worlds top rated oscilloscope? really 

Hmmm... at first I thought you were misreading, as the eMail header says "World's Best Selling Oscilloscope Now Only $349 + $745 in FREE Software".

But they really did have the chutzpah to say that on the graphic, didn't they? 

They do and that is why I quoted it because I dare say that there are an awful lot of people who would dispute that claim with some passion. That is a blatant lie if ever I saw one.

Then again, they don't say for what rating it's at the top of. So, it's just meaningless marketing wank.

Let's give it some meaning, shall we? For the category of World's Most Often Hacked Oscilloscope, the winner is: Rigol DS1054Z.

[bitseeker]

Welcome to the 100 MHz club.

[mnementh]

Worlds top rated oscilloscope? really 

Hmmm... at first I thought you were misreading, as the eMail header says "World's Best Selling Oscilloscope Now Only $349 + $745 in FREE Software".

But they really did have the chutzpah to say that on the graphic, didn't they? 

They do and that is why I quoted it because I dare say that there are an awful lot of people who would dispute that claim with some passion. That is a blatant lie if ever I saw one.

Then again, they don't say for what rating it's at the top of. So, it's just meaningless marketing wank.

Let's give it some meaning, shall we? For the category of World's Most Often Hacked Oscilloscope, the winner is: Rigol DS1054Z.

Case in point, the preceding post. 

Welcome to the 100 MHz club.

What can I say? Since I bought it, I've needed the features of a DSO, and I've needed the 100MHz BW, but not both in the same machine. So I didn't  feel an urge to mess with it until after it was OOW. 

mnem
 

[GreyWoolfe]

Bread stuffing  not heard of Sage and Onion stuffing then eh  , oh well whatever floats your boat but a whole bird does demand stuffing, we do the stuffing separately, basically for me 

Absolutely bread stuffing!!!!!!  Only I call it dressing as I don't stuff the cavity with it, it's done separately.  The cavity gets stuffed with additional veggies and herbs.  I make a sage sausage and portobello mushroom stuffing that is to die for.  I make it every year.  A couple of years ago, I decided to try something different.  My son made a comment to the effect of: Really, Dad, where is the real stuffing."  I also make a cranberry compote from scratch.  I can't stand that stuff that comes out of a can.

Speaking of Thanksgiving meals, this is the first time in 14 years we have not cooked Thanksgiving dinner because the house was empty as the stepdaughter, her husband and the granddaughter weren't home as the granddaughter was competing in the regional cheerleading competition today and had to be there yesterday.  Since it was just Mrs GreyWoolfe and I, we had Spaghetti Bolognese done how WE like it.  The sauce was leftovers in the freezer and added lots of chopped black and green olives and crushed red pepper flakes.  YUM.

[bitseeker]

Oh, yes. I like spicy spaghetti.

[bd139]

I’ve literally just crawled out of bed and you lot are making me hungry

[Specmaster]

Lol, the same story here, fortunately I'll have breakfast in a minute [emoji4]

[SeanB]

Jalapeno poppers, green jalapeno chillis filled with feta and wrapped with bacon.....

[Cerebus]

Now now Gentlemen. I'm going shopping in a little bit and with you lot going on about food there's a risk that I'll end up hauling home a whole turkey and all the trimmings, and, if the last two Christmases are anything to judge by, the real beneficiary of that would not be me but the cat.

[Ero-Shan]

Hi,

interesting. Do you have a diagram of this one ?
I have built some HV PSUs as well, look here:

https://electronicprojectsforfun.wordpress.com/power-supplies/high-voltage-lab-power-supplies/

Sure. It is your 250 V / 150 mA one. (Thanks for the diagram, hope that's Ok with you.) Although it wasn't too easy to comprehend the lo-res PNG.
I substituted the 2 references (voltage/current) with LM285-2.5, as I had only one TL431 with leads. The pass transistor is a 2SK1773.

I'm undecided whether I should search for a stronger transformer and what to do about heater voltage. I might also add 2 digital panel meters, as I have quite a few of them (Panaplex might be fitting).
But I dread the mechanics. Cases are expensive, and after I've finished my 'machining' they tend to look just horrible. 

[Ero-Shan]

Aah, damnit.

Wolfgang, I owe you an apology. I really should have credited the HV PSU's original designer right at the first post (I was also unaware that the very designer was participating here). I never meant to imply it was my design. My linear design capabilities are, alas, not quite top notch.

Totally unrelated:

There's an Agilent 54641d (complete with probes!) on german fleabay. https://www.ebay.de/itm/302962251973 As I'm not at all happy with my Rigol's logic analyzer, that thing looks interesting to me. What do you think?

[bd139]

Another one here, albeit slightly older: https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F153266555358

I rather like them. I can’t comment on the rigol one. I suspect the Rigol has better triggers.

[Wolfgang]

Hi,

interesting. Do you have a diagram of this one ?
I have built some HV PSUs as well, look here:

https://electronicprojectsforfun.wordpress.com/power-supplies/high-voltage-lab-power-supplies/

Sure. It is your 250 V / 150 mA one. (Thanks for the diagram, hope that's Ok with you.) Although it wasn't too easy to comprehend the lo-res PNG.
I substituted the 2 references (voltage/current) with LM285-2.5, as I had only one TL431 with leads. The pass transistor is a 2SK1773.

I'm undecided whether I should search for a stronger transformer and what to do about heater voltage. I might also add 2 digital panel meters, as I have quite a few of them (Panaplex might be fitting).
But I dread the mechanics. Cases are expensive, and after I've finished my 'machining' they tend to look just horrible. 

Cool ! Of course I have nothing against reproduction of my projects for noncommercial use. Just play safe, then everything is fine.

For heaters there are two solutions:

- separate transformer (the tube audio guys gave those)
- combined anode/heater transformer (also available from tube audio shops).

You can also choose from AC heating (possibly introducing hum into your circuit) or a DC heater power supply (I built some of those too).

Mechanics is almost never loved by electronics people. Its the same with me. One day I got tired of completely improvised constructions and I bought myself a computer controlled mill (CNC Step Hi-Z400T). I then made some tools to handle the Hammond cases and fix them inside the mill. For a more complicated case with a lot of round and rectangular holes (e.g. for panel meter), fan grills, ... this saves a *lot* of manual work. And it is repeatable if needed. So thats the explanation why a lot of my stuff looks so similar.

Another mechanical thing that I found useful is 3D printers. The blue part for the fan grill is such a thing. After some sobering experiences with Stratasys I now found a reasonable 3D printer that works much more reliably (Ultimaker 3). It starts making fun, the last part I made was a plug adapter for the Keysight autoprobe scope connector, like here (at the bottom):

https://electronicprojectsforfun.wordpress.com/using-the-keysight-autoprobe-interface-in-your-own-projects/

A last tip would be the MOSFET pass transistor. In my parts, I am now replacing the 2SKxxx and IRFxxx types by linear MOSFETS from IXYS. The are a bit costly, but they have a SOAR that guarantees that they wont blow up in linear operation. A shorted MOSFET could send your attached circuit to hell immediately, because the full input voltage will be released to it.

Have fun !
   Wolfgang

[Wolfgang]

Aah, damnit.

Wolfgang, I owe you an apology. I really should have credited the HV PSU's original designer right at the first post (I was also unaware that the very designer was participating here). I never meant to imply it was my design. My linear design capabilities are, alas, not quite top notch.

Totally unrelated:

There's an Agilent 54641d (complete with probes!) on german fleabay. https://www.ebay.de/itm/302962251973 As I'm not at all happy with my Rigol's logic analyzer, that thing looks interesting to me. What do you think?

Hi,

to be honest I have never seen a unit like this. I have a Tek scope with logic channels and a Rigol, but I do not have so many digital projects and this is probably the reason I did not have any difficulties with it (I just did some I2C work, trivial stuff).

Sorry for no more info
   Wolfgang

[bd139]

Might be worth grabbing a cheap Chinese Saleae clone these days. I’ve got one. I haven’t actually needed it yet.

[nfmax]

TEA and Audio will be curtailed a bit for me just when it was going so well, I had managed to resurrect a duff CD drive, replace drive belts on a cassette drive then SWMBO shouts up the stairs that the washing machine just bang (did bd139 just pay me a visit I wonder?? ) checked the plug fuse, still OK.

Took the top of the machine and just make out the faint smell of burning, stuffed my head inside and looked around with a good torch and bingo, there was a lovely PCB all encapsulated in resin with a thermistor that looks a bit the worse for wear and many components in the general area of covered in soot, so thats buggered that, Been a good machine though (LG) so its off to Black Friday Sales after all for me 

My dishwasher did that a few years back. It was one of the dreaded RIFA capacitors

[Ero-Shan]

Hi,

interesting. Do you have a diagram of this one ?
I have built some HV PSUs as well, look here:

https://electronicprojectsforfun.wordpress.com/power-supplies/high-voltage-lab-power-supplies/

Sure. It is your 250 V / 150 mA one. (Thanks for the diagram, hope that's Ok with you.) Although it wasn't too easy to comprehend the lo-res PNG.
I substituted the 2 references (voltage/current) with LM285-2.5, as I had only one TL431 with leads. The pass transistor is a 2SK1773.

I'm undecided whether I should search for a stronger transformer and what to do about heater voltage. I might also add 2 digital panel meters, as I have quite a few of them (Panaplex might be fitting).
But I dread the mechanics. Cases are expensive, and after I've finished my 'machining' they tend to look just horrible. 

Cool ! Of course I have nothing against reproduction of my projects for noncommercial use. Just play safe, then everything is fine.

There's absolutely no danger of anything remotely commercial. Thanks again for the design.

For heaters there are two solutions:

- separate transformer (the tube audio guys gave those)
- combined anode/heater transformer (also available from tube audio shops).

The transformer I use right now has two heater windings, but since the mains voltage was raised to 230 volts, they're a tad too high (7.1 volts) for my taste. And I prefer DC, of course. Alas, 7 volts AC doesn't leave enough headroom for regulation to 6.3 volts after full-wave rectification.
A third transformer  just for that? These are the reasons for my undecidedness. And I have plenty of lab supplies (remember the 9 HP E6114A).

You can also choose from AC heating (possibly introducing hum into your circuit) or a DC heater power supply (I built some of those too).

As a first "project", I just want to get some light out of my Magic Eyes. Hum would definitely not be a problem there. But I love regulated supplies, and DC is so much easier in that regard.

Mechanics is almost never loved by electronics people. Its the same with me. One day I got tired of completely improvised constructions and I bought myself a computer controlled mill (CNC Step Hi-Z400T). I then made some tools to handle the Hammond cases and fix them inside the mill. For a more complicated case with a lot of round and rectangular holes (e.g. for panel meter), fan grills, ... this saves a *lot* of manual work. And it is repeatable if needed. So thats the explanation why a lot of my stuff looks so similar.

Another mechanical thing that I found useful is 3D printers. The blue part for the fan grill is such a thing. After some sobering experiences with Stratasys I now found a reasonable 3D printer that works much more reliably (Ultimaker 3). It starts making fun, the last part I made was a plug adapter for the Keysight autoprobe scope connector, like here (at the bottom):

https://electronicprojectsforfun.wordpress.com/using-the-keysight-autoprobe-interface-in-your-own-projects/

Gasp! Of course I keep dreaming about a mill, but that price is not easily justified. For this amount I could get quite a few milled plates from Schaeffer ... And where would I put it?

A last tip would be the MOSFET pass transistor. In my parts, I am now replacing the 2SKxxx and IRFxxx types by linear MOSFETS from IXYS. The are a bit costly, but they have a SOAR that guarantees that they wont blow up in linear operation. A shorted MOSFET could send your attached circuit to hell immediately, because the full input voltage will be released to it.

Yup, the 2SK1773 is intended for SMPS operations. But I see no risk of leaving the DC SOA here. Just for fun, I might try out a few BJT as well (so I actually use some of my components).

Have fun !
   Wolfgang

At least I'm trying!

BTW: The main reason for posting that PSU construction was because I used one of those berated breadboards; "worked first time" was in reference to that.

[Specmaster]

I think the biggest problem with breadboards is that those who use them a lot probably create over time, is that of in time is bad contacts aside from all the RF issues.

[Ero-Shan]

Might be worth grabbing a cheap Chinese Saleae clone these days. I’ve got one. I haven’t actually needed it yet.

Look like the USBee I used at work some times. Too simplistic, I'm afraid.

I had a Kontron LA232 once (now that was a boat anchor, about 35 kg, and deep - when carrying, you had to raise your arm when negotiating stairs lest you bang its bottom against the steps!). The software ran on 5 1/4 inch floppies, OS was CP/M. The whole thing was more like an oven (and loud with 3 big fans). It had to go.
Could have had a LA248 (somewhat newer, but same size) with 48 channels, optional high-speed boards last year. Or a much nicer Kontron PLA/1 (hard disk, MS-DOS, 3.5 inch floppy). But it had some issues with the encoder wheel, so I decided against it (still thinking my Rigol MSO would do nice enough).

This Agilent MSO is also specified to 350 MHz. Depending on the price, it may well be worth the money. HP/Agilent/Keysight usually isn't crap.

[tggzzz]

Of course I keep dreaming about a mill, but that price is not easily justified. For this amount I could get quite a few milled plates from Schaeffer ... And where would I put it?

CNC mills can sometimes be found in a local Hackspace or Makerspace or model engineering club. If so, they come with knowledgeable users

[0culus]

Not specifically TEA, but I got some books in the mail. Time to get systematic about this hobby. 

[bd139]

Good books. Have both. Make sure you check the errata in the learning book. It’s extensive.

[0culus]

Duly noted, thanks!