Author Topic: Test Equipment Anonymous (TEA) group therapy thread  (Read 4315624 times)

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Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73700 on: October 31, 2020, 02:54:21 pm »
Mmmmm... fresh human spread for my morning toast. >:D

mnem

Hmm, toast was of course "flame grilled"  >:D :-DD
Who let Murphy in?

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Offline Neomys Sapiens

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73701 on: October 31, 2020, 02:58:09 pm »
The bargraph is only useful if the variance you want to watch is close to the fullscale measurement range. If I want to spot a 50mV variance on the 0 to 20V range, then the bargraph probably won't change at all, whereas with an analogue meter the needle movement will be visible.

All arguments about "which is best" are kind of pointless anyway. There are plenty of cases where an analogue meter/scope will be more suitable for the job and just as many cases where a digital meter/scope would be better. It's like arguing whether a hammer or a screwdriver is better - It all depends on the task at hand.

McBryce.   
Exactly this, it is why older engineers are likely to have a selection of tools in their kit and will choose the most suitable tool to do the job with. Younger engineers will probably have had zero experience with analogue meters anyway.

It is also another reason why I'm showing interest in the Selectest Super 50 meter as its scale is larger than that of an Avo so any such variation is going to be easier to spot.
So what is behind it? In a company where I had to run some tests I was looking for a different meter (analogue or digital with a really usable bargraph, like my M2035). The subsequent discussion with a co-worker did clearly show what is behind the absence: nobody did speak up against the management zombies who decided what would not be needed anymore, resulting in a one-fits-all minimum solution.


I don't consider me being an older engineer but I do have (collected) some analogue meters for special tasks where the analogue movement shows trends better than any sampling digital meter.
I use them regularly especially for controlling currents. Or for voltages in unknown environments where capacitive voltages with almost no power could easily trick a high impedance digital voltmeter but not a low impedance analogue meter.

My analogue meters have (with exception of two analogue multimeters like the AVO) moving iron movements that are good for AC and DC at the same time. Those have advantages over digital meters in certain situations also.
I can only vindicate this. Going out into 'electrical' situations my Metravo 4S or Unigor A41 (30A range) do serve me well.
 
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Offline Cerebus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73702 on: October 31, 2020, 02:58:20 pm »
I expect the only reason no one has done this yet is because most DMM are not flat-bottomed or deep enough to allow them to stand on end or accept a batten lamp holder, unlike an old Avo  :-//

This leads me to ask the obvious question: Do flat bottomed DMMs make the rocking Lab go 'round?
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 
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Offline 25 CPS

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73703 on: October 31, 2020, 02:58:28 pm »
If I have to explain one more time when I'm trolling,   :rant:

 :-DD


@Robert, the example with the meters you gave is a problem of observation and basic knowledge, rather than any inherent advantage in either technology.

The human eye is an intriguing piece of evolutionary technology; primitive in some aspects, yet astonishingly advanced in others.

In terms of discerning small changes, a good wobbly pointer will always exceed a DMM, for the simple reason that it effectively has infinite resolution*, whereas the DMM has to measure a defined quantum change before it indicates a change, ie for a 20,000 count DMM the magnitude of the reading must change by 0.01% just to flip the LSD, which may sound like a small amount, but compared to the magnitude of a movement the human eye can detect, it's hopelessly imprecise.

Also as you point out, the brain is evolved to use the information from the eyes in a certain way, which can make it faster reading analog output, though I'd argue training the brain is possible in such a way to make the difference negligible, in certain circumstances.

EDIT: * Assuming zero friction in the movement, and perfect linearity in the return spring. Obviously this isn't possible in practice, though I suspect the effective resolution on a good quality unit would still be enough to make a volt/time nut salivate.


Pointer wobble.

On PCC streetcars, the low voltage control power was made by a motor generator set that would use a 600V motor to spin a 32 volt ish generator on the same shaft along with two squirrel cage fans and in some cases a small belt driven air compressor.  Anyhow, the original voltage and regulator was an electromechanical device that would series and shunt regulate the output side of the generator so that it would average somewhere around 34 volts or so to charge the batteries and a second electromechanical device called a reverse current relay would keep the MG set disconnected until it was spinning and had self-excited enough to produce more voltage output than the batteries.  This allowed the self-excitation cycle at startup to happen without it being loaded down and also prevented backward power conversion by motoring the generator side of the MG set off the batteries on the car.

The pointer wobble would come into play on the voltmeter on the dashboard.  The regulator would be switching in and out a series and a parallel resistance on the output side of the motor generator very rapidly to average the output voltage around what it had been set to across whatever range of loading conditions were present on the low voltage systems and the needle would be quivering as the generator ran and the voltage regulator acted on the output and all's good.  If the generator side died or something went wrong with the regulator or reverse current relay, you'd still hear the machine being spun by the motor side but the meter needle wouldn't be quivering.  It'd sit at whatever the voltage of the batteries was when you looked at it and you'd know you had a problem even before the batteries had a chance to drain off enough to seriously lower the pointer out of the range it should be sitting in.

Anyhow, after a lot of place including museums retrofitted these really fast acting solid state regulators in place of the original ones and put a diode in to replace the reverse current relay, the output of the generator would be flat on wherever it was set and the whole idea of looking over at the dashboard meter for pointer quiver as an at a glance check of the health of the motor generator and charging system went out the window.  Oh well.
 
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73704 on: October 31, 2020, 03:04:35 pm »


HAPPY HALLOWEEN!

mnem
Just because you asked so nicely, C...  >:D
 

Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73705 on: October 31, 2020, 03:06:24 pm »
I expect the only reason no one has done this yet is because most DMM are not flat-bottomed or deep enough to allow them to stand on end or accept a batten lamp holder, unlike an old Avo  :-//

This leads me to ask the obvious question: Do flat bottomed DMMs make the rocking Lab go 'round?

Yes, very much so. Just as wiggly lines in a wire make the IntardNet go 'round. ;)

mnem
 :-/O
 
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73706 on: October 31, 2020, 03:14:30 pm »


mnem
 

Offline Saskia

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73707 on: October 31, 2020, 03:32:16 pm »
be nice and good, otherwise
 
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73708 on: October 31, 2020, 03:48:42 pm »


mnem


 
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Offline Saskia

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73709 on: October 31, 2020, 03:55:18 pm »
pffft. Amateur.
See this.
 
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Offline 0culus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73710 on: October 31, 2020, 03:56:46 pm »
Today, I will not be joining discord as I have prior commitments. Have fun, catch everyone next week!
 
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Offline Cerebus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73711 on: October 31, 2020, 03:58:43 pm »
To be fair, that's East Dallas. A call to "multiple dismembered bodies on a front lawn" isn't obviously a hoax/mistake given the locale.
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 
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Offline Saskia

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73712 on: October 31, 2020, 03:59:01 pm »
just picked up 12 boxes with components and hauled them home.
 

Offline Cerebus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73713 on: October 31, 2020, 03:59:26 pm »
Today, I will not be joining discord as I have prior commitments. Have fun, catch everyone next week!

Today, I shall mostly be eating sausages.

« Last Edit: October 31, 2020, 04:04:01 pm by Cerebus »
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 
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Offline Robert763

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73714 on: October 31, 2020, 04:18:54 pm »
Still researching the soldering tin wire market.

One thing is rather strange for me:
Felder Sn60Pb40 -selling to private customers prohibited.
Felder Sn60Pb39Cu1 -no restrictions ?!   :-//

What's up with this 1% replacement Pb -> Cu?
Can anyone report his/her practical experience with this?

OTH
The Balver Zinn bleifrei SN100C- SnCu0,7Ni is reported as the only soldering tin that proofed a NASA reliability test. Nice.  :)

The 1% copper tin / lead alloy was what Multicore here in the UK branded "Savbit". It is supposed to reduce the dissolution of copper from the iron bit or fine wires. Also a slightly stronger joint. Used to use it all the time at work.
 

Offline Robert763

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73715 on: October 31, 2020, 04:28:18 pm »
If I have to explain one more time when I'm trolling,   :rant:

 :-DD


@Robert, the example with the meters you gave is a problem of observation and basic knowledge, rather than any inherent advantage in either technology.

<SNIP>

You are correct about knowledge, The poit you have missed is that digital technolgy is not always "better" (more accurate) than analog. Even for multimeters a given digitial meter is not better than all analog meters.
 
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Offline mansaxel

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73716 on: October 31, 2020, 04:49:05 pm »

The Balver Zinn bleifrei SN100C- SnCu0,7Ni is reported as the only soldering tin that proofed a NASA reliability test. Nice.  :)

Does anyone understand where to buy the BalverZinn? I'd love to try it. I've shot off a question about availability to the appointed distributor for Sweden, but I'm not likely to get an answer until Monday.

Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73717 on: October 31, 2020, 05:33:10 pm »
@Cerebus, I've never, at least that I can remember, come across Jesse before. I presume that he was on the TV at some point, more likely a regional program rather than a national one?
Who let Murphy in?

Brymen-Fluke-HP-Thurlby-Heathkit-Thander-Tek-Extech-Black Star-GW-Advance-Avo-Kyoritsu-Amprobe-ITT-Robin-TTi
 

Online nfmax

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73718 on: October 31, 2020, 05:40:44 pm »
BT Openreach staff gather together and put on their festive costumes for the traditional Halloween 'trick or treat' tour of our local cable ducting
 
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Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73719 on: October 31, 2020, 05:43:03 pm »
Either that or they’ve discovered dogging and are trying to get some in before lockdown.
 
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Online nfmax

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73720 on: October 31, 2020, 05:46:07 pm »
Shortly after I took that picture an eleventh van turned up. Some sort of football-themed tribute to Nobby Stiles, perhaps?

When I came back a few hours later there were cable drum dispensers near some of the manhole covers: looks like they were putting in new ducting, dare I hope for blowing in fibre in the near future? FTTP = Fibre To The Promises
 

Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73721 on: October 31, 2020, 05:52:06 pm »
Took 3 years after they did that here. Don't hold your breath.
 
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Offline Mr. Scram

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73722 on: October 31, 2020, 05:55:20 pm »
BT Openreach staff gather together and put on their festive costumes for the traditional Halloween 'trick or treat' tour of our local cable ducting
Doesn't quite ook like the required distance, now does it?
 
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Online BU508A

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73723 on: October 31, 2020, 05:56:49 pm »

The Balver Zinn bleifrei SN100C- SnCu0,7Ni is reported as the only soldering tin that proofed a NASA reliability test. Nice.  :)

Does anyone understand where to buy the BalverZinn? I'd love to try it. I've shot off a question about availability to the appointed distributor for Sweden, but I'm not likely to get an answer until Monday.

How about a group buy from that ebay Kleinanzeigen in Germany?
I'd keep a roll and the other ones I'd sell for 18 Euro plus shipping?
Anyone who's interested can drop me a pm.
“Chaos is found in greatest abundance wherever order is being sought. It always defeats order, because it is better organized.”            - Terry Pratchett -
 

Offline AVGresponding

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #73724 on: October 31, 2020, 05:57:45 pm »
More likely just gathering for Fat Friday (Friday sandwiches from a greasy spoon).
nuqDaq yuch Dapol?
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