Author Topic: Test Equipment Anonymous (TEA) group therapy thread  (Read 4342731 times)

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Offline bsfeechannel

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33400 on: June 19, 2019, 12:30:55 am »
Got the parts to convert the OL-1 tube filament to DCV and the results are "good enough" to consider this project as complete.

As I expected, the DC filament voltage is low under load because I'm rectifying the 6.3VAC filament from the power transformer. I'm getting 5.7VDC which is low but it works...just barely. Initially the waveform was extremely difficult to sync. I changed the sync tube (12AX7) and it's now stable. It's just a matter of selecting tubes which will operate a reduced filament voltage. I could fix this by installing a separate power transformer with regulation but I don't think it's worth the effort. So this guy is done and considering where it started from I can feel good that it's mission accomplished.  :-+

Interesting solution. Guitar amp modders use a trick that is to balance the filament winding using two resistors.



Sometimes they use a potentiometer instead of two resistors to finely adjust the cancellation of hum.


« Last Edit: June 19, 2019, 12:36:28 am by bsfeechannel »
 

Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33401 on: June 19, 2019, 12:39:39 am »
BNC are fine in my book, a pox on the bugger/s who keeps putting PL259\SO239 on equipment!

I have no problem with BNCs in principle... it's just that PARTICULAR one was a pretty jank hack, which was not med's fault at all. But since med decided to keep it, now I have something to noodge him about besides the "2465 Fan Bodge of DOOM".  :-DD

mnem


 

Offline bitseeker

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33402 on: June 19, 2019, 12:40:36 am »
We've made it to leet level. Welcome to page 1337 (for those playing at default settings, knudge, knudge, wink, wink).
I TEA.
 

Offline Carl_Smith

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33403 on: June 19, 2019, 12:52:52 am »
When I first heard of Python and learned that it used indentation to determine the structure of the code, I was appalled that someone would create a language like that.  But over time I've started to change my mind.  For one, it forces people to actually indent code properly.  Also, it prevents abominations like this:

Code: [Select]
if (condition) {
  code here;
} else {
  other code here;
}


Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33404 on: June 19, 2019, 12:53:29 am »
I also love BNC's, so convenient.  :-+
Who let Murphy in?

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Online med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33405 on: June 19, 2019, 01:06:58 am »
BNC are fine in my book, a pox on the bugger/s who keeps putting PL259\SO239 on equipment!

I have no problem with BNCs in principle... it's just that PARTICULAR one was a pretty jank hack, which was not med's fault at all. But since med decided to keep it, now I have something to noodge him about besides the "2465 Fan Bodge of DOOM".  :-DD

mnem


BOOM!!



 :P :P :P :P :P :P :P :-DD :-DD :-DD
An old gray beard with an attitude.
 
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33406 on: June 19, 2019, 01:56:18 am »
Sorry.... was that a picture you posted med? I can't see it, since I'm wearing my Bodge-Blocker Sunglasses™...  8)

mnem
 :bullshit:
 

Online Brumby

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33407 on: June 19, 2019, 02:21:15 am »
You gave it a name - and you must have said the name 3 times!!!


Mnem ... where do you get those glasses?
 

Offline worsthorse

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33408 on: June 19, 2019, 03:04:12 am »
Sorry.... was that a picture you posted med? I can't see it, since I'm wearing my Bodge-Blocker Sunglasses™...  8)

mnem
 :bullshit:

I used to own a pair of those but one day all my TE disappeared from my bench while I was wearing them so I gave them away.    ;D
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Offline GregDunn

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33409 on: June 19, 2019, 03:35:14 am »
When I first heard of Python and learned that it used indentation to determine the structure of the code, I was appalled that someone would create a language like that.  But over time I've started to change my mind.  For one, it forces people to actually indent code properly.  Also, it prevents abominations like this:

Code: [Select]
if (condition) {
  code here;
} else {
  other code here;
}

Exactly why I accept/tolerate Python's structure requirement.  Code blocks should be clearly set apart and decipherable to a reader who didn't grow up with the original coder.   ;D  This isn't BASIC, where whitespace takes up part of your precious 16K of memory.  I used to get teased about the way I wrote Java and other "modern" languages because I refused to spaghetti-thread or declare dozens of classes which made the code ghastly to read.
 

Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33410 on: June 19, 2019, 03:43:10 am »
We've made it to leet level. Welcome to page 1337 (for those playing at default settings, knudge, knudge, wink, wink).



NARRRF!!!

mnem
$#17!
« Last Edit: June 19, 2019, 04:31:38 am by mnementh »
 

Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33411 on: June 19, 2019, 03:53:36 am »
You gave it a name - and you must have said the name 3 times!!!

mnem ... where do you get those glasses?

Yeah; I was expecting that from med... actually sooner, TBH. ;) - Sorry... sometimes I repeat myself... repeat myself... repeat myself...   :P

I got mine from wch... he was having a conniption fit about all his gear hiding from him unless he looked sideways at it... :o

mnem
Awww, man... where'd my Steelers socks go?
 

Online beanflying

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33412 on: June 19, 2019, 03:59:00 am »
You gave it a name - and you must have said the name 3 times!!!

mnem ... where do you get those glasses?

Yeah; I was expecting that from med... actually sooner, TBH. ;) - Sorry... sometimes I repeat myself... repeat myself... repeat myself...   :P

I got mine from wch... he was having a conniption fit about all his gear hiding from him unless he looked sideways at it... :o

mnem
Awww, man... where'd my Steelers socks go?

Now offering felt Blue Bodge Blockers by @ Beanfliying. The idea has to be worth squillions  >:D
Coffee, Food, R/C and electronics nerd in no particular order. Also CNC wannabe, 3D printer and Laser Cutter Junkie and just don't mention my TEA addiction....
 

Offline 0culus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33413 on: June 19, 2019, 04:08:33 am »
....and now for something completely different...




Can anyone recommend a good source for NON-sleeved banana test leads that I can use with the 427A and my 3455A? Both are 1 kV max dc.
 

Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33414 on: June 19, 2019, 04:35:40 am »
You gave it a name - and you must have said the name 3 times!!!

mnem ... where do you get those glasses?

Yeah; I was expecting that from med... actually sooner, TBH. ;) - Sorry... sometimes I repeat myself... repeat myself... repeat myself...   :P

I got mine from wch... he was having a conniption fit about all his gear hiding from him unless he looked sideways at it... :o

mnem
Awww, man... where'd my Steelers socks go?
Now offering felt Blue Bodge Blockers by @ Beanfliying. The idea has to be worth squillions  >:D
bean, izzat you? All I can see is blue fuzz...

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Offline Tomorokoshi

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33415 on: June 19, 2019, 05:08:16 am »
....and now for something completely different...




Can anyone recommend a good source for NON-sleeved banana test leads that I can use with the 427A and my 3455A? Both are 1 kV max dc.

I have cut the sleeves off with a sharp razor blade. It was either a Fluke or Pomona set.
 
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Online beanflying

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33416 on: June 19, 2019, 05:22:10 am »
....and now for something completely different...




Can anyone recommend a good source for NON-sleeved banana test leads that I can use with the 427A and my 3455A? Both are 1 kV max dc.

DIY?

Plenty of options for buying 4mm gold bullets from the R/C market plus the usual electronic suspects. One of my 10AWG sets for high current use (40-60A if needed) next to an evilbay one (10A max before they melt).

Fat tip soldering iron and a little Lead/Silver solder for preference.
Coffee, Food, R/C and electronics nerd in no particular order. Also CNC wannabe, 3D printer and Laser Cutter Junkie and just don't mention my TEA addiction....
 
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Online tggzzz

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33417 on: June 19, 2019, 07:35:16 am »
When I first heard of Python and learned that it used indentation to determine the structure of the code, I was appalled that someone would create a language like that.  But over time I've started to change my mind.  For one, it forces people to actually indent code properly.

That's a non-problem with most languages: use an IDE to force indent the code in a standard way with a single keystroke.

That's impossible with Python.
There are lies, damned lies, statistics - and ADC/DAC specs.
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Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33418 on: June 19, 2019, 07:39:34 am »
That feature isn’t necessary. By nature of the indentation being structural, the code is correctly indented if it works.
 

Online tggzzz

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33419 on: June 19, 2019, 07:45:53 am »
Code blocks should be clearly set apart and decipherable to a reader who didn't grow up with the original coder.   ;D  This isn't BASIC, where whitespace takes up part of your precious 16K of memory.

Quite right.

Quote
I used to get teased about the way I wrote Java and other "modern" languages because I refused to spaghetti-thread or declare dozens of classes which made the code ghastly to read.

With a modern (i.e. <15 years old) IDE you don't "read code", you "browse code". The IDE creates its own internal representation of the code, and provides keystrokes to rapidly move around the codebase.

The principal uses of classes inheritance and instantiation are:
  • to allow someone to have a good guess at what they don't have to look at - saves masses of reading!
  • to allow composability
  • to allow a client to say "I'd like one of those, except it differs in this way"
  • to allow a client to say "can we have another one of those as well"

Nonetheless, all techniques and technologies can be and are misused. Good taste is important, and rare. Some people should never be let near a keyboard.
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Online nfmax

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33420 on: June 19, 2019, 07:48:30 am »
Dang didn't think of that  :-DD ... it does tend to go off if it goes flat though.

issue 2 will have a low voltage cutoff. Thanks for the heads up! I'll get issue 1 working first and thoroughly test it. Should be able to achieve that with a fat low Rds(on) MOSFET, comparator and TL431 off the top of my head.
Here's how I did it: https://www.eevblog.com/forum/projects/battery-undervoltage-lockout/msg1060148/#msg1060148
 
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Online tggzzz

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33421 on: June 19, 2019, 07:52:41 am »
W.r.t. autoformatting.

That feature isn’t necessary. By nature of the indentation being structural, the code is correctly indented if it works.

That's a circular justification!

And how often have you seen unit tests that are sufficiently good that they can spot the effects of changed indentation? Most unit tests I've seen are dismal; all that mattered was getting the green light, since that defined that it worked. Cough, splutter.

The problems arise with unspotted fat fingers, cut and paste operations, inserting/removing level.

None of those are insurmountable, but having explicit delimiters increases the chance that the compiler will spot an infelicity, and reduces the opportunities for error.
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33422 on: June 19, 2019, 08:02:17 am »
It is exactly that. Which is intentional because it puts style and correctness in the same domain. When they are not, it makes functional interpretation of what’s in front of you more difficult. C case statements are a brilliant little hole where this goes to hell.

Also how do you know your code still works if you don’t test it? Hence goto fail mentioned earlier which would have been picked up if they had a test suite that was worth more than a bag of crisps.

But throwing all of this aside, where do you think the biggest risks are? Mostly in interpreting the problem domain competently. Case in point I watched some code destroy 100k archived financial documents  once because a business analyst misread archival requirements. The code did what it was told efficiently and without mercy. Edit: try and understand OAuth2 without leaving a hole the size of a bus in something :)
« Last Edit: June 19, 2019, 08:05:28 am by bd139 »
 

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33423 on: June 19, 2019, 08:06:35 am »
Dang didn't think of that  :-DD ... it does tend to go off if it goes flat though.

issue 2 will have a low voltage cutoff. Thanks for the heads up! I'll get issue 1 working first and thoroughly test it. Should be able to achieve that with a fat low Rds(on) MOSFET, comparator and TL431 off the top of my head.
Here's how I did it: https://www.eevblog.com/forum/projects/battery-undervoltage-lockout/msg1060148/#msg1060148

Thanks for that - appreciated! I had something very similar brewing in my head :)
 

Online tggzzz

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #33424 on: June 19, 2019, 10:01:39 am »
It is exactly that. Which is intentional because it puts style and correctness in the same domain. When they are not, it makes functional interpretation of what’s in front of you more difficult.

Prettyprinting and correctness should not be in the same domain.
Without correctness, prettiness is irrelevant - unless you are an artiste :)
With correctness, given a suitable language and IDE, prettiness is merely two clicks away! We're not working with 5 channel paper tape on 5cps telytypes anymore!

Prettiness ought to be easy.

Quote
C case statements are a brilliant little hole where this goes to hell.

There are far worse problems with C than that!

Quote
Also how do you know your code still works if you don’t test it?

You can't test quality into a product.

Quote
Hence goto fail mentioned earlier which would have been picked up if they had a test suite that was worth more than a bag of crisps.

But throwing all of this aside, where do you think the biggest risks are? Mostly in interpreting the problem domain competently. Case in point I watched some code destroy 100k archived financial documents  once because a business analyst misread archival requirements. The code did what it was told efficiently and without mercy. Edit: try and understand OAuth2 without leaving a hole the size of a bus in something :)

That's why validation and verification are two separate disciplines. Figuring out what to do ought to be more difficult than doing it.

There are many pitfalls to creating and maintaining something that is correct. Pitfalls shold not be introduced unnecessarily.

Regrettably some tools introduce problems that other tools avoid. Such tools shold be deprecated.
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 


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