Test Equipment Anonymous (TEA) group therapy thread

[med6753]

Geez, it's gonna take me an hour to catch up. 

[tggzzz]

Agreed, most capacitors are rated at 20% even so it could be argued that 10% is even too high for most items anyway.

40 years ago I made a filter with a Q of 4000 using 20% capacitors. It was a modern implementation of the concept given in a Bell Labs paper from 1960.

[Specmaster]

$US60 vs $US110... looks like everybody else figured out what I did when I was shopping it.

Nope. Still not willing to give up the tweezers, DUT slots and factory cal for $50. Sorry. 

mnem
 

Thats fine, I wasn't asking you to, I mentioned it as an alternative for the benefit of others who might not be able to justify a DE5000 anyway.  This is just pure basic watering hole chatter but you are still missing the point, it comes with a factory calibration, the point of the bag of resistors is that you can also do your own at any point in its life as the reviewer actually stated, he checked the values against his super accurate Keithley meter and the XLW01 also concurred with the Keithley. 

EDIT
The only time it will come without factory calibration is if you buy the kit to build it yourself.

[mnementh]

Sorry... you're right.  I was being a bit of a butt-head aboot it.    There's probably a fair bit of confirmation bias in my feelings towards the DE-5000.

mnem
 

[Specmaster]

@memn, I understood that but needed to clarify the point for those playing along at home 

[mnementh]

Fair enough. I just love everything that comes with the DE-5000; it's like the MS8911 in that respect. Just such a juicy "The Whole Package" deal. When you're counting every dollar, obviously you need to go with what does the job you need; not buy for what you want.

mnem
 

[0culus]

   

https://www.amazon.ca/4-Digital-Precision-Adjustable-Regulated-Switching/dp/B07MFLYSWL

Currently looking at this 150W RF White Noise Generator Bench Power Supply as it's only CAD$85/US$65 with Prime Next-Day. How much extra fire insurance should I buy along with...?

mnem
What could possibly go wrong...?

Save your money and get a linear bench supply, is my advice. We already have enough crappy EMI emitters in the world. 


I would say that the pcb shot doesn't inspire confidence...not much physical separation between the primary and secondary parts of the SMPS.

[mnementh]

I said I was looking... not that I was daft enough to buy it.

Actually, now that I think of it, I probably just felt like agitatin'; I tripped over that while I was looking for the Aven PCB thing. 

mnem
*agitating-ily*

[Wolfgang]

   

https://www.amazon.ca/4-Digital-Precision-Adjustable-Regulated-Switching/dp/B07MFLYSWL

Currently looking at this 150W RF White Noise Generator Bench Power Supply as it's only CAD$85/US$65 with Prime Next-Day. How much extra fire insurance should I buy along with...?

mnem
What could possibly go wrong...?

Mnem, I have to frustrate you to keep you from a bad experience. The noise is *massive*, but *not* white. 

[SilverSolder]

You and I and most of the old buzzards in here know that.

But that's because we know how to use a analog meter because we grew up with them. I bet one in a thousand of the current crop of *ahem* "EEs" groks that in any significant way. And less than one in a thousand of THEM are going to be willing/able to sell that to their pointy-haired boss. 

They're just going to get the single-purpose specialized test set for whatever application they're working on; or trust what they see on the screen of their half-million dollar DSO/MSO and use that for their "certifications".

Case in point... go to the FCC website and pick a few random FCC "certifications" for some pieces of gear that emit RF, either accidentally or on purpose. Look at the test setups used for validation. All are painstakingly well-documented, but the actual test setups are often utterly cringeworthy; enough to make a real EE from our generation cry. And I ain't claiming to be one; while I may cling to the fact of having held the title a few times, I'm at best a jackleg EE with just enough knowledge to grok how little I actually know. Even I cringe at some of what I've seen there.

mnem

Taking a break, waiting for a coat of paint to dry before applying a 2nd coat.

The Fluke 87 is an absolutely wonderful instrument. But it's bargraph is worse than useless. I've tried, several times, to use it to align IF cans on receivers and it just doesn't cut. It jumps around then suddenly changes ranges and you have no idea where you are. Break out the VTVM on low AC volts and presto, done in 2 minutes. 

The 87-IV (or 189 as they later came to be labeled ) is the polar opposite; they knew the bargraph on previous 87s was a point of contention, and they made the 87-IV so it could be configured for peak, mean and averaging. It WORKS well... but still no comparison in usability to a nice big 4-6 inch analog needle.

Again... you and I know this on a visceral level.

Most of today's "EEs", when faced with any analog display, get a look on their face like a tree full of owls. And they're the ones who drive product development, and the ones who sell their pointy-haired bosses on the tools they "need" to do their jobs.

mnem
 

Isn't it just a matter of turning on a little averaging on a modern meter, to emulate the slow analogue gauge response?

[tautech]

   

https://www.amazon.ca/4-Digital-Precision-Adjustable-Regulated-Switching/dp/B07MFLYSWL

Currently looking at this 150W RF White Noise Generator Bench Power Supply as it's only CAD$85/US$65 with Prime Next-Day. How much extra fire insurance should I buy along with...?

mnem
What could possibly go wrong...?

If you want/need a compact SMPS consider the 30V 5A MCH K305D.
Threads on them here and schematics have been posted.
Had one for years and still use it regularly.

Sure it's not a clean PSU, it's a SMPS FFS but it is well behaved with zero overshoot etc.

[mnementh]

You and I and most of the old buzzards in here know that.

But that's because we know how to use a analog meter because we grew up with them. I bet one in a thousand of the current crop of *ahem* "EEs" groks that in any significant way. And less than one in a thousand of THEM are going to be willing/able to sell that to their pointy-haired boss. 

They're just going to get the single-purpose specialized test set for whatever application they're working on; or trust what they see on the screen of their half-million dollar DSO/MSO and use that for their "certifications".

Case in point... go to the FCC website and pick a few random FCC "certifications" for some pieces of gear that emit RF, either accidentally or on purpose. Look at the test setups used for validation. All are painstakingly well-documented, but the actual test setups are often utterly cringeworthy; enough to make a real EE from our generation cry. And I ain't claiming to be one; while I may cling to the fact of having held the title a few times, I'm at best a jackleg EE with just enough knowledge to grok how little I actually know. Even I cringe at some of what I've seen there.

mnem

Taking a break, waiting for a coat of paint to dry before applying a 2nd coat.

The Fluke 87 is an absolutely wonderful instrument. But it's bargraph is worse than useless. I've tried, several times, to use it to align IF cans on receivers and it just doesn't cut. It jumps around then suddenly changes ranges and you have no idea where you are. Break out the VTVM on low AC volts and presto, done in 2 minutes. 

The 87-IV (or 189 as they later came to be labeled ) is the polar opposite; they knew the bargraph on previous 87s was a point of contention, and they made the 87-IV so it could be configured for peak, mean and averaging. It WORKS well... but still no comparison in usability to a nice big 4-6 inch analog needle.

Again... you and I know this on a visceral level.

Most of today's "EEs", when faced with any analog display, get a look on their face like a tree full of owls. And they're the ones who drive product development, and the ones who sell their pointy-haired bosses on the tools they "need" to do their jobs.

mnem
 

Isn't it just a matter of turning on a little averaging on a modern meter, to emulate the slow analogue gauge response?

Ehhhh... A high-impedance digital meter will process some spikes which a analog meter will ignore. Also, noisy signal can drive a digital meter batshit-crazy, but will just show up as a wiggly needle on analog, which will still allow you to see the overall trend clearly. And... for many people, a needle over a white panel is still a lot easier to resolve with the eye than any LCD/VFD/OLED bargraph.

Analog still has its place, both with meters and scopes, which are still better at characterizing noise than most DSOs.

mnem
 

[McBryce]

   

https://www.amazon.ca/4-Digital-Precision-Adjustable-Regulated-Switching/dp/B07MFLYSWL

Currently looking at this 150W RF White Noise Generator Bench Power Supply as it's only CAD$85/US$65 with Prime Next-Day. How much extra fire insurance should I buy along with...?

mnem
What could possibly go wrong...?

You know it's got to be good when one of the four selling points is that it comes with a UL power cable.

McBryce.

[bd139]

It has UL written on it anyway. It's probably got aluminium melty wire in it.

[tautech]

It has UL written on it anyway. It's probably got aluminium melty wire in it.

Yep.
Had a customer/fishing buddy send back a MCH K305D recently with the complaint it didn't work....dead as a doornail !   

Plugged an IEC cable into it and the thing worked fine.
Luckily he had sent the mains cable he'd been using and it was one of those gawd awful alloy conductor POS with broken wires near the IEC plug. Not the one the PSU was supplied with though. 
Promptly chopped it up and filed it in the bin !

[Saskia]

Fleabay win: those 2 Quadral Altan boxes will be resuscitated, I got 2 woofers for 25$. Still have one semi-good tweeter sitting around, and the one that's out of specs will be refurbished.

A winner for 125€, those things have very decent quality.

[factory]

Whole switch. Not sure if the wafers are compatible or not - full data here: https://www.blore-ed.com/rotaryswitches

You can buy individual parts. They have some on their shop page but will ship anything in 1-off quantities and even make up new pots for you!! Also super helpful on the phone!

Thanks for the link, I will have a good look through at their shop to see if I can find something some parts similar to the multiplier switch in the recently acquired 5243L (H16) and hopefully modify my HP 5245L in the future to have both the 100 & 1000 second gate time options (H18), just need to find some cheap 5212A-65C boards as well.


Note: they pushed the original reset switch back and added a extra rod through the rotary switch shaft to actuate the reset button behind.

David

[Saskia]

had one of those Korad 3005s that was DOA, it would power up, but the output relays would not click, etc.

Opening it up revealed that the cable was not connected.

I would have complained if I had paid full price. But plugging in that cable was a fix that even I was capable of, and I got it for 80 Pesos.

I'm not complaining.

[Saskia]

hey, you already have to put up with my wimpering for 1000 posts  fascinating.

[bd139]

It has UL written on it anyway. It's probably got aluminium melty wire in it.

Yep.
Had a customer/fishing buddy send back a MCH K305D recently with the complaint it didn't work....dead as a doornail !   

Plugged an IEC cable into it and the thing worked fine.
Luckily he had sent the mains cable he'd been using and it was one of those gawd awful alloy conductor POS with broken wires near the IEC plug. Not the one the PSU was supplied with though. 
Promptly chopped it up and filed it in the bin !

Ugh. My first experience with one of them was one that got rather hot. I though it had just worn out but nope the conductor was completely broken about an inch from the IEC plug and it was arcing 

[tonyalbus]

It's "Columbus Day" here and schools are closed as well as some other places. This is the day we supposedly celebrate Christopher Columbus "discovering" America. Despite the fact that people were already here, what we call "Native Americans". Over the last few years there have been calls to rip down all the statues dedicated to Columbus which has got the people of Italian descent all up in arms because he was Italian working for Spain.   

That's pretty funny actually. Human race is a complete shit show.

Well I didn't get my day off. Turns out someone fudged something so been called out

Edit: fire out. Thinking about snagging one of these. This is mostly to hold boards while I'm working on them because the infernal things keep disappearing due to the weight of test leads etc.

   Anyone got any better solutions because it's the best part of 100 quid? 

https://www.amazon.ca/Aven-17010-Adjustable-Circuit-Holder/dp/B00Q2TTQEE/

This one works well for MOST PCB work, but it has a few limitations. It is mostly plastic, so it will weaken and embrittle with age. Mine hasn't YET, but I know it will. The base parts are steel tube, so it is more rigid than it looks and bottom-weighted JUST enough to be stable for most PCB/assembly work. The rotation clamps work well as long as you use BOTH; use one and the work will spin pretty easily. You just have to be careful every time when tightening them down, especially if you have big ol' hamhands like mine. This my expected point of failure: the plastic cracking out from overtightening the thumbscrews, or just plain repetitive stress fatigue.



That said... I also have that PanaVise... and for the quality, it's a fucking bargain. It's a tool you'll use the rest of your life and never find it wanting, plus the No 303 mini-vise that fits in the same base is just handy as a pocket on a shirt for only $40-ish.

Compared to the above plastic fantastic, it had better bottom-weighting, holds the board much more solidly, and the big thing... you can set the PCB ANY compound angle, so you can get EXACTLY the right angle of attack at a hard-to-reach component or solder pad on densely populated boards.



https://www.amazon.ca/Helping-Soldering-Workshop-Non-Slip-Weighted/dp/B07TTZCZPR

Add to that these little gems, and you have a lab-grade soldering workstation with wiring holders and iron management in a closet-stuffable portable package.



https://www.amazon.ca/PanaVise-324-Electronic-Work-Center/dp/B000SSPNBU

This is the Panavise station made for production assembly work... I've used one, but don't own it. It's all about quick turnover of repetitive assembly work, and worth every penny for that application.

Trust me... you will NEVER regret the money spent on PanaVise... what you'll regret once you have it is not having done it decades ago.

mnem
 

i have that blue..thing...its about 7 euro's  and its great!!!

[25 CPS]

First off, to all the Canadians here, happy thanksgiving!

When Mnemnth and I met up for coffee the other day and we were chatting about test equipment and all, I was showing pictures of some of the locally built oddities for which there’s either very little or no documentation out there.  Back in late June 2017 I found a listing for an HP 523D counter nearby and I was able to get in touch with the gentleman selling it and dropped by on my way to work to pick it up. It was listed for $40 but while I was on my way there, he decided to give it to me along with this Measurement Engineering Ltd. signal generator free of charge since they’d been listed for several months and since nobody had expressed any interest, were going to be put in his town’s ewaste recycling in a few weeks had I not called.

I brought both into work that afternoon since one of the other guys there enjoys vintage stuff like this and we spun up the HP 523D counter and put the columnar displays through their paces with a handheld signal generator since it was demonstrated working when I picked it up, and took the cover off the MEL.  There’s a smudged stamp inside that almost implies a 1939 build year and the style of the cabinet tends to agree but then I wonder if it was made post war out of surplus parts because when I researched the company, there were a a couple archival newspaper articles I found online about how much the company liked moving to Arnorior, which is the location given on the front panel, and this was a post war article.  The only other thing I could find was a trademark history that shows the Measurement Engineering Ltd. name and logo were bought by Canadian Stackpole who registered it and then renewed it once, then ultimately let it lapse in 1984.  We didn’t attempt to power it up because it clearly needs an electrical restoration but one of the guys at work was saying that it’s like some of the equipment he worked on when he was a new employee that was built by defunct companies that have little or no record that they ever existed online.  Not everything is on the internet.

Here are some pictures:



Built in Arnprior, Ontario and last calibrated a very, very long time ago by ITT Canada who may, at one time, have had documentation on this machine.



The top deck shows a tube complement that I believe is all pre-war.  When I looked up the introduction dates on the tubes used in this machine back in 2017 when it was first given to me, they were all pre-war with one (forgotten which) that scraped in with a 1939 introduction date.  So the tube compliment and the style of the case plus the one fuzzy stamp inside the chassis suggests a build date in 1939, but, on the other hand, that doesn't square with the one newspaper article from the early fifties I found that talked about how Measurement Engineering Limited liked moving to Arnprior as if it had just happened.  Without any other information that I could find out there, the build date and approximate age are a mystery.  But look at that beautiful four gang tuning capacitor and the transformers and choke!



The underside of the chassis.  Those heavy porcelain insulators are beautiful as is the looming job on the wiring.  Correct me if I'm wrong but I thought the standard Wein bridge oscillator and Hewlett-Packard (and companies that cloned the HP circuit) used a single lightbulb but MEL's circuit uses two of them so it may not be an exact clone.

This signal generator's been sitting on the shelf in my boat anchor collection since I got it but since having coffee with Mnemnth and showing pictures, I've started to get an itch to pull this off the shelf and do an electronic restoration on it to get it running in a couple of weeks once the autumn yard work is out of the way and it starts getting crappier outside.  Is there any interest in seeing pictures of the restoration process?

[factory]

I just missed two working HP 3456’s for £50 and £65 each elsewhere 

That HP 740B was a bargain at £40, I hope it has gone to someone that will repair it & use it.
Someday I hope to find one too, so far I only have the a manual and the input/output boxes, can't say I've seen one on ePay in the UK for a very long time.

David

[factory]

First off, to all the Canadians here, happy thanksgiving!

When Mnemnth and I met up for coffee the other day and we were chatting about test equipment and all, I was showing pictures of some of the locally built oddities for which there’s either very little or no documentation out there.  Back in late June 2017 I found a listing for an HP 523D counter nearby and I was able to get in touch with the gentleman selling it and dropped by on my way to work to pick it up. It was listed for $40 but while I was on my way there, he decided to give it to me along with this Measurement Engineering Ltd. signal generator free of charge since they’d been listed for several months and since nobody had expressed any interest, were going to be put in his town’s ewaste recycling in a few weeks had I not called.

I brought both into work that afternoon since one of the other guys there enjoys vintage stuff like this and we spun up the HP 523D counter and put the columnar displays through their paces with a handheld signal generator since it was demonstrated working when I picked it up, and took the cover off the MEL.  There’s a smudged stamp inside that almost implies a 1939 build year and the style of the cabinet tends to agree but then I wonder if it was made post war out of surplus parts because when I researched the company, there were a a couple archival newspaper articles I found online about how much the company liked moving to Arnorior, which is the location given on the front panel, and this was a post war article.  The only other thing I could find was a trademark history that shows the Measurement Engineering Ltd. name and logo were bought by Canadian Stackpole who registered it and then renewed it once, then ultimately let it lapse in 1984.  We didn’t attempt to power it up because it clearly needs an electrical restoration but one of the guys at work was saying that it’s like some of the equipment he worked on when he was a new employee that was built by defunct companies that have little or no record that they ever existed online.  Not everything is on the internet.

Here are some pictures:

Certainly in the UK at least surplus parts were used after WWII in all sorts of stuff including test gear, I have a small oscilloscope from the late 1940's with AM (Air Ministry) branded vacuum bulbs, I have run it for a very short time and it does work & display a trace, but it needs a lot of Hunts capacitors replacing to make it work well.

David

[med6753]

First off, to all the Canadians here, happy thanksgiving!

When Mnemnth and I met up for coffee the other day and we were chatting about test equipment and all, I was showing pictures of some of the locally built oddities for which there’s either very little or no documentation out there.  Back in late June 2017 I found a listing for an HP 523D counter nearby and I was able to get in touch with the gentleman selling it and dropped by on my way to work to pick it up. It was listed for $40 but while I was on my way there, he decided to give it to me along with this Measurement Engineering Ltd. signal generator free of charge since they’d been listed for several months and since nobody had expressed any interest, were going to be put in his town’s ewaste recycling in a few weeks had I not called.

I brought both into work that afternoon since one of the other guys there enjoys vintage stuff like this and we spun up the HP 523D counter and put the columnar displays through their paces with a handheld signal generator since it was demonstrated working when I picked it up, and took the cover off the MEL.  There’s a smudged stamp inside that almost implies a 1939 build year and the style of the cabinet tends to agree but then I wonder if it was made post war out of surplus parts because when I researched the company, there were a a couple archival newspaper articles I found online about how much the company liked moving to Arnorior, which is the location given on the front panel, and this was a post war article.  The only other thing I could find was a trademark history that shows the Measurement Engineering Ltd. name and logo were bought by Canadian Stackpole who registered it and then renewed it once, then ultimately let it lapse in 1984.  We didn’t attempt to power it up because it clearly needs an electrical restoration but one of the guys at work was saying that it’s like some of the equipment he worked on when he was a new employee that was built by defunct companies that have little or no record that they ever existed online.  Not everything is on the internet.

Here are some pictures:



Built in Arnprior, Ontario and last calibrated a very, very long time ago by ITT Canada who may, at one time, have had documentation on this machine.



The top deck shows a tube complement that I believe is all pre-war.  When I looked up the introduction dates on the tubes used in this machine back in 2017 when it was first given to me, they were all pre-war with one (forgotten which) that scraped in with a 1939 introduction date.  So the tube compliment and the style of the case plus the one fuzzy stamp inside the chassis suggests a build date in 1939, but, on the other hand, that doesn't square with the one newspaper article from the early fifties I found that talked about how Measurement Engineering Limited liked moving to Arnprior as if it had just happened.  Without any other information that I could find out there, the build date and approximate age are a mystery.  But look at that beautiful four gang tuning capacitor and the transformers and choke!



The underside of the chassis.  Those heavy porcelain insulators are beautiful as is the looming job on the wiring.  Correct me if I'm wrong but I thought the standard Wein bridge oscillator and Hewlett-Packard (and companies that cloned the HP circuit) used a single lightbulb but MEL's circuit uses two of them so it may not be an exact clone.

This signal generator's been sitting on the shelf in my boat anchor collection since I got it but since having coffee with Mnemnth and showing pictures, I've started to get an itch to pull this off the shelf and do an electronic restoration on it to get it running in a couple of weeks once the autumn yard work is out of the way and it starts getting crappier outside.  Is there any interest in seeing pictures of the restoration process?

Your 1939 date is probably correct. The four tubes on the upper part of chassis are 8 pin octal which were introduced in the late 1930's. The big boy on the bottom is probably the rectifier tube and most likely a Type 80 four pin tube.

Correction....looking at the underside picture the rectifier is also an octal so it's most likely a 5U4.