Test Equipment Anonymous (TEA) group therapy thread

[tggzzz]

Yeah, but that one's extra special ex-BBC - one look at it and you tell it was used on the Black and White Minstrel Show.  I'm rather surprised that it doesn't come with a little straw boater and a stripy blazer.

I use two ways of enlightening youngsters as to how much progress our generation enabled:

• yootoob vids of the Black and White Minstrel show, the most popular Saturday night programme in the 1960s and early 70s
• the plot essentials of one of the few movies to win 9 oscars (including best picture), the glossy family-friendly musical "Gigi"

Something that I found hard to believe even at the time. My parents watched it, therefore I had to sit through it. Ignoring the obvious, it was also the tritest, dullest show on TV - it made the potter's wheel look positively captivating. It was like a Smith's song - watch one number and you've effectively seen every other number and experienced the full range of their expressive capabilities. Utter garbage, but then the Great (unwashed) British public was never known for their great taste - in defence of which argument I offer three words "Watney's Red Barrel".

Yeah, my parents also watched it, never saw the appeal personally, much preferred to watch some good comedy programs. I do however admit to enjoying "Love thy Neighbour", a show that attempted to make fun out of the racists.

Till Death Us Do Part can't be shown on TV because people don't recognise that Alf Garnett and his attitudes are being held up for ridicule.

[tggzzz]

Yeah, but that one's extra special ex-BBC - one look at it and you tell it was used on the Black and White Minstrel Show.  I'm rather surprised that it doesn't come with a little straw boater and a stripy blazer.

I use two ways of enlightening youngsters as to how much progress our generation enabled:

• yootoob vids of the Black and White Minstrel show, the most popular Saturday night programme in the 1960s and early 70s
• the plot essentials of one of the few movies to win 9 oscars (including best picture), the glossy family-friendly musical "Gigi"

If you want some "good" old british TV comedy try "Forces TV" feeding squaddies 80's TV.......

That does appear to show the stuff no other channel will touch.

But anyone that did what the characters in Gigi did would be locked up in jail for a long time and vilified in the press.

[Specmaster]

Yeah, my parents also watched it, never saw the appeal personally, much preferred to watch some good comedy programs. I do however admit to enjoying "Love thy Neighbour", a show that attempted to make fun out of the racists.

Till Death Us Do Part can't be shown on TV because people don't recognise that Alf Garnett and his attitudes are being held up for ridicule.

Yep, totally agree, I also used to watch that as well, most of the modern comedy programs are so sterile they almost cease to be funny for fear of upsetting someone. Fawlty Towers was another great program.

[Andrew_Debbie]

I may be wrong, but if memory serves the MacPro  and aluminium Power Mac power supplies were all manufactured by Delta.

I think you are correct.   If I had a dead one, I would take it apart  but they all work.     I have eight in my office.  Two are in use, one is a hot spare and the others are waiting for someone to come and borrow them.   Usually most of them are out on loan but Covid changed everything.


Even today  a ten year old dual CPU  8 core  MacPro has enough compute power to be useful.   

[Cerebus]

Any device tying neutral and ground together within the device is verboten here and as you stated would have to be checked.

Not quite what I was thinking. A lot of people make the assumption that one of the two mains wires coming into a piece of equipment is at or near ground potential, more so if you have a clearly defined neutral like the UK does. It's an assumption that does not get tested when you plug something into a supply where the assumption is true (outside of fault conditions). That assumption is obviously not true if you connect to a US style 240V supply where the centre tap is at ground and both 'hot' and 'return' have significant AC potentials with respect to ground.

The danger here, as I see it, is not conscious design per se but casual assumptions like "Oh, that component is OK, as it can only see neutral and ground it'll only see more than a couple of volts" or "Yes, the clearance and creepage are tight there, but it's only a neutral." that tend to get ingrained because that's all you ever see domestically. It's probably only going to be corner cases and unusual use cases at that, but I'm only too aware of the dangers of "ploughing a rut" in any field of endeavour. We've all seen cases where unspoken assumptions come around to firmly bite someone on the arse. If and when that happens I strongly prefer it if it's not my assumption or my arse.

[Cerebus]

I may be wrong, but if memory serves the MacPro  and aluminium Power Mac power supplies were all manufactured by Delta.

I think you are correct.   If I had a dead one, I would take it apart  but they all work.     I have eight in my office.  Two are in use, one is a hot spare and the others are waiting for someone to come and borrow them.   Usually most of them are out on loan but Covid changed everything.


Even today  a ten year old dual CPU  8 core  MacPro has enough compute power to be useful.

Hey, who needs a screwdriver when they have image search - "mac pro power supply":



That's a Delta logo there.

[Cerebus]

Till Death Us Do Part can't be shown on TV because people don't recognise that Alf Garnett and his attitudes are being held up for ridicule.

Bunch of silly old moos. 

[ch_scr]

Any device tying neutral and ground together within the device is verboten here and as you stated would have to be checked.

Not quite what I was thinking. A lot of people make the assumption that one of the two mains wires coming into a piece of equipment is at or near ground potential, more so if you have a clearly defined neutral like the UK does. It's an assumption that does not get tested when you plug something into a supply where the assumption is true (outside of fault conditions). That assumption is obviously not true if you connect to a US style 240V supply where the centre tap is at ground and both 'hot' and 'return' have significant AC potentials with respect to ground.

The danger here, as I see it, is not conscious design per se but casual assumptions like "Oh, that component is OK, as it can only see neutral and ground it'll only see more than a couple of volts" or "Yes, the clearance and creepage are tight there, but it's only a neutral." that tend to get ingrained because that's all you ever see domestically. It's probably only going to be corner cases and unusual use cases at that, but I'm only too aware of the dangers of "ploughing a rut" in any field of endeavour. We've all seen cases where unspoken assumptions come around to firmly bite someone on the arse. If and when that happens I strongly prefer it if it's not my assumption or my arse.

The regulation in germany (with it's reversible plugs) is even such that it's not defined which side is hot and which side is neutral on the outlet 
All the VDE "Verband Deutscher Elektrotechniker "-regulation says, it should be "the same within the whole installation" -
So the "it's per definition undefined" is deeply engrained here.

[tggzzz]

Yeah, my parents also watched it, never saw the appeal personally, much preferred to watch some good comedy programs. I do however admit to enjoying "Love thy Neighbour", a show that attempted to make fun out of the racists.

Till Death Us Do Part can't be shown on TV because people don't recognise that Alf Garnett and his attitudes are being held up for ridicule.

Yep, totally agree, I also used to watch that as well, most of the modern comedy programs are so sterile they almost cease to be funny for fear of upsetting someone. Fawlty Towers was another great program.

There is too much design by committee, design by focus group, and design for factory conveyor belt production.

But there was also a lot of crap back in the golden age f our youth. Sturgeon's Law applies.

[mnementh]

Introducing:.     my new US Lab version beta 0.01.

about 8 meters x 3 meters, I can dance tarantella now.. uh feet, inches, sorry whaaat?

A few infos:

1) Relocation from EU to USA. On the 29th March I packed up everything. It arrived here on the 17th of freaking July.... they told me corona times... would you believe them? Muppeeeetsssssss
2) the mains here in US are a shit show, I already found and corrected few errors in the electrical system in my home. Safety forget about it... but for 0.0924 €/KWh I can't complain too much...
3) First project. Spectrum Modem IPV6/64 and pfSense... Tsunami of shit coming... anyway I want and need to learn the IPV6 jazz better...
4) Second: Wireup/Setup a 220VAC 60HZ Eu/Schuko (thanks to the Germans!) plugs in my US home... this will be a fun one... do you guys wants some videos series about it? If you push me I could start a YT channel...
5) Good news, shitty blue CAT5 running in the entire home... will put a switch behind those old telephone lines...
6) What I have to do with all 10 Kms of coax cables they wire up in almost every freaking room? I do and not want to have a SAT system and decoders... What I should do with them?   Thanks for all who asked about me and sent PM!

PS: I can't believe it I am back..... ahh finally again TEAAAAAAA

Welcome back Z! 

mnem
No need to unpack; you're almost back to civilization. Just few hunnerd more miles northeast....

[Specmaster]

Any device tying neutral and ground together within the device is verboten here and as you stated would have to be checked.

Not quite what I was thinking. A lot of people make the assumption that one of the two mains wires coming into a piece of equipment is at or near ground potential, more so if you have a clearly defined neutral like the UK does. It's an assumption that does not get tested when you plug something into a supply where the assumption is true (outside of fault conditions). That assumption is obviously not true if you connect to a US style 240V supply where the centre tap is at ground and both 'hot' and 'return' have significant AC potentials with respect to ground.

The danger here, as I see it, is not conscious design per se but casual assumptions like "Oh, that component is OK, as it can only see neutral and ground it'll only see more than a couple of volts" or "Yes, the clearance and creepage are tight there, but it's only a neutral." that tend to get ingrained because that's all you ever see domestically. It's probably only going to be corner cases and unusual use cases at that, but I'm only too aware of the dangers of "ploughing a rut" in any field of endeavour. We've all seen cases where unspoken assumptions come around to firmly bite someone on the arse. If and when that happens I strongly prefer it if it's not my assumption or my arse.

Wouldn't it be better to do the reverse of what we sometimes had to do with American equipment, and have a 120 to 240 step up transformer and fit special polarised sockets that the transformer(s) are plugged into in order to ensure that the neutral is just that?

[BU508A]

But anyone that did what the characters in Gigi did would be locked up in jail for a long time and vilified in the press.

I've just read the plot of this "Gigi" thing.
https://en.wikipedia.org/wiki/Gigi_(1958_film)

 

What a stinking pile of shit this is.     

[Zucca]

Could you provide a picture of the consumer unit? I'm always curious. :-)

Be careful, some of the NFPA70 practices are quite different from EN. For example, usually the installation cables don't get RCD protection, because it's done via GFCI socket outlets. That's not a fault like it would be in most of Europe, it's a different safety vs. availability philosophy.

Ohh I know that, will do something reasonable! As for the pictures... I will make a video...

[Zucca]

What do you want to do? Installing a 25kW transformer in the basement? 

No. It would be pure madness.

I have two 220VAC phases 180° looking at me at the main panel... and I already shop for EU main panels and stuff in Germany.... and also some overvoltage protection.... it would be the safest 220VAC in the entire north america (yes also canada civilized territory too where dragons are allowed to live in peace)

[McBryce]

Introducing:



my new US Lab version beta 0.01.
about 8 meters x 3 meters, I can dance tarantella now.. uh feet, inches, sorry whaaat?

A few infos:

1) Relocation from EU to USA. On the 29th March I packed up everything. It arrived here on the 17th of freaking July.... they told me corona times... would you believe them? Muppeeeetsssssss
2) the mains here in US are a shit show, I already found and corrected few errors in the electrical system in my home. Safety forget about it... but for 0.0924 €/KWh I can't complain too much...
3) First project. Spectrum Modem IPV6/64 and pfSense... Tsunami of shit coming... anyway I want and need to learn the IPV6 jazz better...
4) Second: Wireup/Setup a 220VAC 60HZ Eu/Schuko (thanks to the Germans!) plugs in my US home... this will be a fun one... do you guys wants some videos series about it? If you push me I could start a YT channel...
5) Good news, shitty blue CAT5 running in the entire home... will put a switch behind those old telephone lines...
6) What I have to do with all 10 Kms of coax cables they wire up in almost every freaking room? I do and not want to have a SAT system and decoders... What I should do with them?

Thanks for all who asked about me and sent PM!

PS: I can't believe it I am back..... ahh finally again TEAAAAAAA

I thought you are married? How did you manage to get "permission" for that much lab space?? 

McBryce.

[BU508A]

This is America, everything is bigger over there. Houses too. 

[McBryce]

This is America, everything is bigger over there. Houses too. 

I could be living in a Tesla Gigafactory and still only get permission for the smallest of rooms

McBryce.

[mnementh]

...

whereupon he's all like:

ch_scr  — Today at 6:05 PM
fuck
you know I have to make me one as well?
thanks I guess    

And he means from scratch out of his parts bins, just because... 

But he posted a vid showing how to do what I wanted with the nanoVNA; and damn if he didn't get me back: Next in my yoobToob queue was this little gem, which sucked up another half-hour of my life...
...

Found two reasonable "primary" source for info on the dg-mos fet probe:
T. Hirschbüchler Bachelor Thesis on the "Design of a low-cost 1 GHz Active Probe" with "conception, construction and evaluation"
https://content.instructables.com/ORIG/FQZ/1QZP/IPJTFO82/FQZ1QZPIPJTFO82.pdf
and the layout from elektor with the gimmick-cap on the pcb:
https://www.elektormagazine.com/files/magazine/2004/dolo/040108-PCB.pdf

That link is borked (at least for me); it may be behind a paywall. I've attached the .pdf below. 

Also, I actually found that article while doing my own research; however I didn't agree with two primary features of his construction technique:

1), his pogo pins are just too long. Everything I've read on the subject aside from his article indicates that ~5mm or less is the ideal length here.

And B) the pin spacing is just ridiculously too wide (yes, I understand the reasons) to actually be a useful probe for most of the kind of stuff you'll use it for.  The really good thing aboot the  60dbmcom probe is the big pads for soldering pins to; you can easily reconfigure to match almost any needed pin spacing.   



https://www.ebay.com/itm/174764316127

There's also this one; it supposedly has specs from the actual device (not just copied from the Elektor article), and I like that the total signal path is as short as possible; however, it was 2x the price and completely unreasonable delivery time. Also it does not use the gimmick capacitor and no pad for GND pin, which is part of the reason the Elektor design uses a dual-gate FET.

mnem
 

Here's my hot take on it

You really want the gimmick cap that is part of the original Elektor project; by it's nature it has less interaction with the rest of the circuit, and it gives you a natural place to tune for desired -20db response by trimming the gimmick cap.  And no, you definitely need SMA output, and a nice short rg174 cable.

This is all part of the discussions I linked to earlier.

Sorry for not tidying up my posts like i usually do; I'm replying on our way to get passports for the kids and working from my tablet. Text editing on which is roughly akin to trying to shave your ballsack with a freerunning jackhammer.  

mnem
 

[Zucca]

The regulation in germany (with it's reversible plugs) is even such that it's not defined which side is hot and which side is neutral on the outlet 
All the VDE "Verband Deutscher Elektrotechniker "-regulation says, it should be "the same within the whole installation" -
So the "it's per definition undefined" is deeply engrained here.

Yes amen to that. I can't imagine anything in EU with a schuko plug that require the "hot wire" somewhere....
If something smokes I will post here Cerebus.

anyway, good ideas for my first YT video:

1) comparison EU vs US main standards and safety practices.
2) How to rewire some US home to get the EU stuff running safely.

[Andrew_Debbie]

But anyone that did what the characters in Gigi did would be locked up in jail for a long time and vilified in the press.

I've just read the plot of this "Gigi" thing.
https://en.wikipedia.org/wiki/Gigi_(1958_film)

 

What a stinking pile of shit this is.     

A little ironic that director  Vincente Minnelli's daughter starred in Cabaret, which won 7 academy awards.     I like Cabaret as much as I dislike Gigi. 

Last time I watched Cabaret was in Atlanta.  I remember more than a few people in the diverse audience were in drag.

[Andrew_Debbie]

2) How to rewire some US home to get the EU stuff running safely.

That is something I've given some thought to.   We may eventually move back to the US.    I would not want to do anything that is not to code, like installing BS 1363 sockets in the kitchen.
Anything not to code will fail during a sales inspection.  Not sure about insurance, but not being covered can be very bad. 
 

That leaves putting NEMA 6-15  or 14-30 sockets in  and making a safe adapter  that plugs into the 'to code'  NEMA socket.  ​



No matter what, there is the problem that either side of a US 240V line is 120V above neutral / ground.   Ground is  bonded to neutral at the main panel.   

[Zucca]

Anything not to code will fail during a sales inspection.  Not sure about insurance, but not being covered can be very bad. 

Oh yes... it will be future sale event proof. No worries.

PS: In Brüstungskanal we trust.

[BU508A]

Thealit ftw? 

[Zucca]

Hager,  sweet and easy.

[vk6zgo]

Any device tying neutral and ground together within the device is verboten here and as you stated would have to be checked.

Not quite what I was thinking. A lot of people make the assumption that one of the two mains wires coming into a piece of equipment is at or near ground potential, more so if you have a clearly defined neutral like the UK does. It's an assumption that does not get tested when you plug something into a supply where the assumption is true (outside of fault conditions). That assumption is obviously not true if you connect to a US style 240V supply where the centre tap is at ground and both 'hot' and 'return' have significant AC potentials with respect to ground.

The danger here, as I see it, is not conscious design per se but casual assumptions like "Oh, that component is OK, as it can only see neutral and ground it'll only see more than a couple of volts" or "Yes, the clearance and creepage are tight there, but it's only a neutral." that tend to get ingrained because that's all you ever see domestically. It's probably only going to be corner cases and unusual use cases at that, but I'm only too aware of the dangers of "ploughing a rut" in any field of endeavour. We've all seen cases where unspoken assumptions come around to firmly bite someone on the arse. If and when that happens I strongly prefer it if it's not my assumption or my arse.

It works the other way round, too--------a device designed for the US 240v system will possibly have a Mains filter with capacitors from each "hot" leg to chassis.
If "chassis" is connected to the ground, the highest voltage across either cap will be maximum 120v, so a 200v rated cap is quite sufficient.
Even if there is no ground connection to the chassis, it is at a "virtual" ground potential.

Now, use the same device in the Australian "230v Live & Neutral" system.
If there is no ground connection to chassis, the capacitors become a voltage divider, with the chassis at 115v ("nominal"--often more) w.r.t Neutral/ ground.

This is not normally dangerous, as the current available through such caps is quite small.

If the chassis is returned to ground, one cap has the usually small (single figure or less) voltage difference between Neutral & ground across it, but the other one must withstand almost the full Live/Neutral voltage, so the "adequate" 200v rated cap is no longer so.