Test Equipment Anonymous (TEA) group therapy thread

[bd139]

Project time!

Some really low brow, low digits T&M action this evening: testing an old analogue panel meter I have. This is being used shortly for a project which I will detail.



So the project in question has been on the go for the best part of 10 years and materialised in reality about 4 years ago. The ultimate goal is to build a fairly boring sounding voltmeter. This went through several incarnations already.

The first was a simple 2n3819 based differential amplifier which required some nulling and a high supply voltage.





The second was a slightly improved version with an RCA jack for probes. This had an interchangeable RF, AC and DC voltage probe sets (not pictured). The ranges weren't good enough on this one. It did develop a power LED reminding the end user that the battery would melt if you left it on.



The last one I did used a CMOS opamp and worked off single rail and 9v battery. This had better ranges. But the meter movement was crappy as was my labelling which made it a chore to use. Also the thing didn't have a massive battery in it so kept falling over.



So bring on 2021 and the nice 10/30 ranged 1mA movement turns up. As does a nice black Eddystone box that will fit it.

New incarnation incoming...

Why am I building these crappy things? Well at the end of the day there's something about using something you built to solve problems and create more things that is magical 

Edit: these are still packed away in a box somewhere too 

[Kosmic]

anyone think this would be useful?   maybe for blowing shit up?

https://www.ebay.com/itm/Bio-Rad-3000Xi-Computer-Controlled-Electrophoresis-Power-Supply/164758676742?hash=item265c61e506:g:6yEAAOSws9ZezCBH

High Voltage lowish current. The big issue with Electrophoresis PSUs is the protection circuits. Any leakage current to ground will cause (most of) them to shut down. They can be useful for capacitor charging or breakdown testing but not always the best option. That one is at least cheap if shipping is OK.

I got a more recent version of the Biorad 3000. Paid around 30$USD. The protection can be bypassed on my unit. The info was in the manual. The voltage range and current are not bad. But regulation is poor. So it's limiting it's usefulness.



P.S: In the picture my high voltage probe is off. So the meter on the supply might be accurate.

[mnementh]

Fucking Lenovo... why the hell can't they just let you have the BIOS update in a file to update from the BIOS anymore...? 

It's either a Windoze utility or a .iso . Which Rufus sez is fuck-you-fer-ized.

So now I have to either find a optical drive and a blank disk... or let the stoopit thing boot off the old HDD one last time, and hope it doesn't fuckerize my BIOS.

*trying to remember how to do it from Command line now...*

mnem
Even Marley singing 3 Little Birds can't make this feel better...

[25 CPS]

I came back home from work yesterday and it was a bit cool in the house.  Look over at the indoor/outdoor thermometer and the indoor temperature confirms what I’m feeling so I go to the living room and check the thermostat.  That thermostat, the one I did the post about back in September and the screen was blank again.  I never did replace the batteries that were in it then when I got it working again by cleaning up the oxidized contacts because after all the grief they gave me, I was determined to get every bit life out of them.  Apparently that life ran out while I was at work.  I changed them out for the set I got ready in September and the heat came back to life.

Of course I had to measure the dead ones just to see what kind of voltage the thermostat drops out at:





Definitely dead, at least dead enough to kill the thermostat for a few hours until I got home.

[mnementh]

Lucky you didn't come home to frozen pipes with the way the wind's been blowing the last few days. My sinuses have been killing me. 

mnem
*dusty dried-out ol' dwagon*

[BU508A]

Fucking Lenovo... why the hell can't they just let you have the BIOS update in a file to update from the BIOS anymore...? 

It's either a Windoze utility or a .iso . Which Rufus sez is fuck-you-fer-ized.

So now I have to either find a optical drive and a blank disk... or let the stoopit thing boot off the old HDD one last time, and hope it doesn't fuckerize my BIOS.

*trying to remember how to do it from Command line now...*

mnem
Even Marley singing 3 Little Birds can't make this feel better...

For exactly this case I'm having an USB stick (bootable of course) with an emergency Windows on it.
In the German IT journal c't was an article about how to build such a thing. They have done a whole framework for building such an USB stick.
Article (in German): https://www.heise.de/ct/artikel/c-t-Notfall-Windows-2021-4954598.html

The main point is: if you want, I can upload an image of this USB stick and when you are having a running  Linux you can simply download the image and with the dd command create a bootable USB stick. Please let me know if you want it, then I'll upload it and send you the URL.

[25 CPS]

Lucky you didn't come home to frozen pipes with the way the wind's been blowing the last few days. My sinuses have been killing me. 

mnem
*dusty dried-out ol' dwagon*

I swear this house is both blessed and cursed with respect to heat in the winter.

It was actually above zero here yesterday and the house had only cooled off a couple of degrees.  It actually took me a few minutes of unloading stuff in the kitchen and taking my jacket off to realize that the temperature had dropped a bit and I was second guessing myself until I glanced over at the indoor/outdoor thermometer.

It was winter when I was looking at houses, I looked at this one and everything was fine the first time.  The second time, it was warmer outside than in.  My real estate agent called the listing agent freaking out about the heat being off.  I spun the thermostat and nothing happened so I went downstairs to push the reset button on the oil burner and see if I could get it on again but I decided to check the simple stupid stuff just in case and walked over to the oil tank.  The float gauge was below the bottom of the scale.  As soon as I saw that, I knew what happened and didn't bother with the reset button.  The house was unoccupied and obviously nobody was stopping in to check on the oil tank every so often.  I left an incandescent light on in each room before the real estate agent and I left to try and prop the temperature up a bit.

That's three times that I know of that the heat's bailed out but it never got cold enough inside to break pipes, thankfully.

[BU508A]

Quick update to the PD 2005A:

After running continously for more than 10 days it seems that it has reached now its stable point.
Perhaps.

[mnementh]

Fucking Lenovo... why the hell can't they just let you have the BIOS update in a file to update from the BIOS anymore...? 

It's either a Windoze utility or a .iso . Which Rufus sez is fuck-you-fer-ized.

So now I have to either find a optical drive and a blank disk... or let the stoopit thing boot off the old HDD one last time, and hope it doesn't fuckerize my BIOS.

*trying to remember how to do it from Command line now...*

mnem
Even Marley singing 3 Little Birds can't make this feel better...

For exactly this case I'm having an USB stick (bootable of course) with an emergency Windows on it.
In the German IT journal c't was an article about how to build such a thing. They have done a whole framework for building such an USB stick.
Article (in German): https://www.heise.de/ct/artikel/c-t-Notfall-Windows-2021-4954598.html

The main point is: if you want, I can upload an image of this USB stick and when you are having a running  Linux you can simply download the image and with the dd command create a bootable USB stick. Please let me know if you want it, then I'll upload it and send you the URL.

I'll lose it. 

This is what I use Rufus for; it does all that and pretty reliably too. In fact, I got so used to using it, I forgot how to DiskPart. But now DiskPart won't make a partition on a USB drive Active, so I gave up and gambled on rebooting with the old HDD. As the BIOS utility came up and confirmed the image against checksum, I'm not going to worry aboot it.

Hmmm... you know what, just out of curiosity, please do. I'm curious if Rufus will see it as good and burn a bootable USB under Win10 now.

mnem
 

[BU508A]

@mnem:

I'll do it, but tomorrow. Here it is now 01:30am in the morning and I need really go to bed.
As a side-note: It is not the newest Wind10 build (I think it is one or two builds below it).
If you want the newest version, let me know. It'll took me ca. 30min to create a new one.
For the USB stick I recommend a size of 8GByte.

Good luck with your data rescue project. 

[mnementh]

Yeah; whatever you've got handy is fine. I'm not running bleeding-edge HW anymore.



On a more positive note: Even with all the interruptions over the last week, I did actually manage to get a cable (as in one; singular) made up and sleeved on my own PC.

mnem
*toddles off to do couch tuber time widda boi while wifey's laptop does Winbloze Updates*

[Cerebus]

In the German IT journal c't was an article about how to build such a thing.

A journal I've never been able to see on a newsstand in Germany without initially thinking the title was elided English swearing. 

[mansaxel]

Ah home IT support. Glad I have one less client three days. She was the worst 

I've set up a new computer for the parents. Migrating crap over wasn't fun, and getting the
bank login (multifactor with chip-and-pin card) working is never easy.

The single most irritating part of windows admin, though, is that there is no good, natural way to make sure all user files end up on a network share. It's like "network" never happened for real in Redmond. I'd rather have a diskless workstation that swaps to NFS than that.

[mansaxel]

The first was a simple 2n3819 based differential amplifier which required some nulling and a high supply voltage.

At this part in the posting, I'm thinking "VTVM" 

Edit: these are still packed away in a box somewhere too 

You know you want to! Are you going with the trick I first saw at Gyraf Audio of turning one transformer "around" and driving its 12V side from he first ones 12V winding?

[tautech]

Started troubleshooting the Type 321A. As I suspected it's a Time Base Issue. The Trigger Circuit is working correctly and there's an excellent trigger pulse into Q135. And that's where it goes to crap. The output on the collector of Q145 is some weak spikes. I'm going to pull those 2 transistors plus Q183 and check them.

A question. Both Q135 ans Q145 are NPN GE. Q183 is PNP GE. Silicon equivalents 2N3904 and 2N3906. Now I read that you should double the value of the emitter resistor if you sub them in. True?   

My Tek Xref lists 151-0108 as 2N2501 on p175

The Xref lists 2N2501 as a 40V device so it seems it's sailing close to the wind and might benefit from a higher V rated sub.

[bd139]

Ah home IT support. Glad I have one less client three days. She was the worst 

I've set up a new computer for the parents. Migrating crap over wasn't fun, and getting the
bank login (multifactor with chip-and-pin card) working is never easy.

The single most irritating part of windows admin, though, is that there is no good, natural way to make sure all user files end up on a network share. It's like "network" never happened for real in Redmond. I'd rather have a diskless workstation that swaps to NFS than that.

That’s dead easy but you need active directory so designed for corporate use only.

Best option for the end user on windows is to install onedrive and just use that. Works pretty well.

[bd139]

The first was a simple 2n3819 based differential amplifier which required some nulling and a high supply voltage.

At this part in the posting, I'm thinking "VTVM" 

Edit: these are still packed away in a box somewhere too 

You know you want to! Are you going with the trick I first saw at Gyraf Audio of turning one transformer "around" and driving its 12V side from he first ones 12V winding?

Yep that’s exactly the plan. Step it down to 12v for both filaments in series in the 12AU7. Then step it back up for the anode voltage.

[Robert763]

Got notification from ebay that the Supernova charger had been delivered but I've received nothing. Royal Mail says it was delivered at 9:45. I was within 3 ft of the door bell from 7:30 to 10:30 so even with the lack of a dog  I would not have missed them. No other post and nothing left outside.
On the plus side the Wasp Thermal imager WAS delivered (Parcel Force). Seems  to work fine. Picture is daylight taken from screen of TV so not ideal. Not great for close focus but I have a ouple of options for that. Pretty good for the money.

your thermal imager looks like a flir in a target aquisition system.

How much do you want for it ? 

It's ITAR restricted (30 frame per second video) so I can't sell it to you

[med6753]

Started troubleshooting the Type 321A. As I suspected it's a Time Base Issue. The Trigger Circuit is working correctly and there's an excellent trigger pulse into Q135. And that's where it goes to crap. The output on the collector of Q145 is some weak spikes. I'm going to pull those 2 transistors plus Q183 and check them.

A question. Both Q135 ans Q145 are NPN GE. Q183 is PNP GE. Silicon equivalents 2N3904 and 2N3906. Now I read that you should double the value of the emitter resistor if you sub them in. True?   

My Tek Xref lists 151-0108 as 2N2501 on p175

The Xref lists 2N2501 as a 40V device so it seems it's sailing close to the wind and might benefit from a higher V rated sub.

Yea, both you and bd are right. Q135 and Q145 are sillycon 2N2501. I had assumed they were GE without checking the parts list first. My bad. 

Something is preventing that multivibrator from properly starting up. The problem is that entire circuit is a giant feedback loop so it could be just about anything. ONE TIME when I powered up the scope I got a beautiful trace....for a few seconds then it went to crap again. I'm thinking about trying to isolate the feedback loop and see if it starts up. That will prove it's OK and I'll have to chase beyond it.

But.....this project might get put on the "back burner" for a while. I'm working on a potential score that might result in an extended road trip tomorrow.     

[bd139]

Creaking floorboards type of score? 

[mansaxel]

That’s dead easy but you need active directory so designed for corporate use only.

Best option for the end user on windows is to install onedrive and just use that. Works pretty well.

Onedrive is in Dante's 8th circuit. I have a Samba AD. Will do another attempt. Actually found a guide for it.

Having said that, roaming profiles, as they're implemented, is something that makes me think Redmond deserves nukes from orbit. Once more, just to be certain.

[med6753]

Creaking floorboards type of score? 

More like collapsed floorboards. 

Stay tuned. 

[bd139]

That’s dead easy but you need active directory so designed for corporate use only.

Best option for the end user on windows is to install onedrive and just use that. Works pretty well.

Onedrive is in Dante's 8th circuit. I have a Samba AD. Will do another attempt. Actually found a guide for it.

Having said that, roaming profiles, as they're implemented, is something that makes me think Redmond deserves nukes from orbit. Once more, just to be certain.

Roaming profiles were ok until some idiot decided to turn all the stuff in peoples home directory into hard links to make it user friendly. Then it became a shit show. So they hacked it by adding LocalLow and Local directories which just made it worse.

As for onedrive, that and Azure AD together under O365 are pretty nice. For once it just works. The domain is dead as we knew it. And I’m glad because I was an AD and Exchange admin in a couple of small businesses over the years and I’d rather electrocute myself to death via my balls than do it again.

New world: buy any old PC with windows OEM install. Pick corporate login on provision. Sign in with Azure AD. Whole machine is provisioned automatically and remotely and all software set up right down to full disk encryption. Plus the contents of onedrive appear on it.  And it even changes the windows SKU to the right one is Pro or Enterprise.

[Saskia]

I hate submitting my data to the Hive. It's just like buying covid vaccine from Umbrella Corporation.

[tautech]

Creaking floorboards type of score? 

More like collapsed floorboards. 

Stay tuned. 

Now just what would make Med shelve his 321A for a bit.....a triple nickel perhaps ?