Test Equipment Anonymous (TEA) group therapy thread

[25 CPS]

Moving Dwagons Update: Home at Last

Today, two very important things happened for us:

1) My wife accepted one of 8 job offers she received over the last week; the pay isn't as good as we were hoping for, but there is opportunity for ancillary income through channels, and there are supposedly regular annual pay increases at this gig. We'll see just how comprehensive the benefits are.

2) We took possession of our new home in West Hartford. Supposedly one of the safest neighborhoods in and around Hartford, with lots of local availability of all sorts of services and shopping, and 10 minutes from the VA Hospital for my dad when he comes.

The place is huge, and there's a whole back section on the ground floor perfect for my dad. He can have as much space as his apartment in NYC, and he won't even know we're here most of the time.

Of course, older 2-story home, and damp basements, etc appears to be a thing we have to deal with.

Honestly, it was all too easy... I was afraid to say a word until we had keys in hand for fear of jinxing it.

maybe Ifni is telling us it's time for the dwagon family to stop rolling for a while.

mnem

I'm glad things are falling into place in Connecticut.  Better Hartford than Stepford!

I'm still surprised they kicked you out of the country but on the other hand the stories in the media about immigration, international students, etc. all being messed up for the last two years have been frequent.  Telling everyone to sit in place and ride the pandemic out while they make adjustments and figure out how to resume doing things out of one side of their mouths and then blaming you for not doing things according to the old way as-was normal until the pandemic showed up out of the other maybe shouldn't be all that surprising.  The truth is, the Canadian government's handling of the pandemic has not been nearly as problem free here as has been claimed.  Anyone who isn't a senior, CERB recipient, work from home laptop worker, but an honest to goodness in the field essential worker can attest to that.

I hope settling into the new place goes smoothly over the next few weeks so you can sit back and relax with your family over the holidays and take a break from all the chaos and house moves.

[med6753]

Troubleshooting the low +350V issue on dusty dawg.

Did some static resistance checks. Snagged it. That diode is open. It's either D702A or D702B. They are 1N3194. 600PIV/1A. 1N4007 are perfect substitution. Will replace both.

[RolandK]

.

[TERRA Operative]

Nice.

I'm currently waiting on parts for a TDS600 PSU.
Was blowing the fuse with great vigour. Turned out one of the two main input switching transistors decided to become a resistor, so I'll replace both for good measure.

[Saskia]

Moving Dwagons Update: Home at Last

Today, two very important things happened for us:

1) My wife accepted one of 8 job offers she received over the last week; the pay isn't as good as we were hoping for, but there is opportunity for ancillary income through channels, and there are supposedly regular annual pay increases at this gig. We'll see just how comprehensive the benefits are.

2) We took possession of our new home in West Hartford. Supposedly one of the safest neighborhoods in and around Hartford, with lots of local availability of all sorts of services and shopping, and 10 minutes from the VA Hospital for my dad when he comes.

The place is huge, and there's a whole back section on the ground floor perfect for my dad. He can have as much space as his apartment in NYC, and he won't even know we're here most of the time.

Of course, older 2-story home, and damp basements, etc appears to be a thing we have to deal with.

Honestly, it was all too easy... I was afraid to say a word until we had keys in hand for fear of jinxing it.

maybe Ifni is telling us it's time for the dwagon family to stop rolling for a while.

mnem

I'm glad things are falling into place in Connecticut.  Better Hartford than Stepford!

I'm still surprised they kicked you out of the country but on the other hand the stories in the media about immigration, international students, etc. all being messed up for the last two years have been frequent.  Telling everyone to sit in place and ride the pandemic out while they make adjustments and figure out how to resume doing things out of one side of their mouths and then blaming you for not doing things according to the old way as-was normal until the pandemic showed up out of the other maybe shouldn't be all that surprising.  The truth is, the Canadian government's handling of the pandemic has not been nearly as problem free here as has been claimed.  Anyone who isn't a senior, CERB recipient, work from home laptop worker, but an honest to goodness in the field essential worker can attest to that.

I hope settling into the new place goes smoothly over the next few weeks so you can sit back and relax with your family over the holidays and take a break from all the chaos and house moves.

I got out of the US the day Trump closed the borders. On the last Lufthansa flight from LAX to FRA.
before leaving I managed to run into a CBP agent who was getting his daily fill of starbucks and I asked him: what happens if I cannot get back and overstay my I-94 ? If you close the borders, how do you handle issues for those who are stuck here ?
His answer: this is a very good question and I will address it to my superiors.

[med6753]

Well crap. Replacing that open diode didn't fix it. Still reading about +295V. But look at that ripple voltage. Nearly 37mV. Spec is 25mV max. Me thinks we got a leaky crapacitor.

[Zucca]

I would like to design a mantis scope lens in the future.

Did you have any experience with free optical design software?

https://exhsw.com/retort-ray-tracer/

https://3doptix.com/

[25 CPS]

I got out of the US the day Trump closed the borders. On the last Lufthansa flight from LAX to FRA.
before leaving I managed to run into a CBP agent who was getting his daily fill of starbucks and I asked him: what happens if I cannot get back and overstay my I-94 ? If you close the borders, how do you handle issues for those who are stuck here ?
His answer: this is a very good question and I will address it to my superiors.

I'm glad you got home alright.  Yes, there have been lots of good questions since March, 2020 but a conspicuous lack of good answers, even now.  At least in Canada there has been no leniency for anybody who got hit by circumstance and went through the cracks and we've seen it over and over again here.

On the subject of moving to new places, I hope your own move is going as well as possible, too.  As my sister says, moving is always more difficult, more expensive, and takes longer than you think, so fingers crossed for the two of you that it's as painless as possible.

[med6753]

Despite the +350V only reading +295V the scope works, sort of. I tried 2 plug-in's with same result. They pass a signal OK but vertical centering and DC balance is WAY off. Not even close. So next step is to replace the filter caps and see what happens.

[Neper]

As my sister says, moving is always more difficult, more expensive, and takes longer than you think...

Or, as they used to say here in Cologne: Dreimol ömjetrocke es einmol afjebrannt. (Three moves equal one house fire.)

[Saskia]

hmmm. you get me thinking ...

nope, not worth it.

[RolandK]

A Hewlett 4342A Q-Meter:
The notes are from the former owner. I think the pexiglas in front of the 2 scales on the left side above the hp plate was made by the former owner, too. But it is perfectly made.

I saw it once on the corner of a picture of an ad. Called the seller, drove 150 miles the next day and picked it up with other things. While i stuffed everything in the car they closed the shop. It was until then that someone arrived and asked if they are closed. I replied yes. He said, he wanted to come with an expert to examine the TEA-stuff. I just answered him there is nothing any more to examine. His face was not very happy, even more, as he looked in my car.





PS: there is an easter egg.

[RolandK]

Some views inside:

[RolandK]

And from down under:

[factory]

I can't believe YHP used those pointer knobs to hold the push button lever mechanisms onto the switches, just seems wasteful. 


Must be an early one too, judging by the blue grey covers.

David

[RolandK]

I was astonished, too.

It is 1028JXXXXXX

In the manual for 1212J-00591 i did not find a change of the knobs. I think they were there, cheap and fitted and in they went.

[factory]

They aren't cheap knobs, they are proper hp parts, usually found on the outside though. 


Just looking at another here and it has normal clamps. https://everist.org/NobLog/20130215_The_Q_meter.htm

David

[mansaxel]

Well, they're wanting Beth to start as soon as Thursday... so for the moment, I'm going to have a full-time job just keeping the kids alive and getting the paperwork done so they can enroll in school. First off, tho, hitting The Thrift for a few "things to sit on and eat off of" until we can arrange for the Trailer of Doom to get here...

Then, I suspect, the ToD will become a full-time job in and of itself for a while. 

Well, there's tools in it! And TE!

mnem
After that...? Honestly, I've been giving some serious thought to trying my hand at voiceover work...

Cool. Not my first guess, but if it works for you, I'm all for it.

[duckduck]

Treated myself to these:

Those are also magic; I put them on the wish list, and they appeared.

For flat, parallel jaws, they're unbeaten. For a more traditional "Polygrip" with serrated jaws (as they're called in Sweden, they're "Wasserpumpenzange" in German, and I'm not certain in English.) I prefer the Bahco over the Knipex:

<snip>
</snip>

The adjustment here is made by pressing the button on the back, which is a more positive size lock than the traditional "open wide, then slide" that Knipex made popular.

Water plump pliers are for plumbers. TEA nerds do need other tools: 

Knipex pliers wrenches are the killer. Smooth jaws and jaws moving in parallel. Available in all sizes and different grip material. Less damage to a nut than any other type of wrench. I've an normal size like an average plumping gnawer and a very small one, able to grip M3 nuts etc.

https://www.knipex.com/products/pipe-wrenches-and-water-pump-pliers/pliers-wrenches-pliers-and-a-wrench-in-a-single-tool/pliers-wrenchespliers-and-wrench-single-tool/8605150

Oh, no! Germany is now manufacturing crack in size XS:

https://www.knipex.com/pliers-wrench-xs

...must...resist...must...not...think...about...its...forged...jaws..and...jewel-like...precision

[DH7DN]

Buy now, regret later 

Knipex

[25 CPS]

I'm going to throw this out there since I know many of you have encountered ham radio operators.  And in this case, an aspiring ham radio operator.

What's the deal with the scanners blaring constantly whenever you have to talk to one of these people?  I hate having to alternately have to shout over and hear through the noise of their scanners.  If you're talking to someone, turn it off or turn it well down.

[med6753]

I'm going to throw this out there since I know many of you have encountered ham radio operators.  And in this case, an aspiring ham radio operator.

What's the deal with the scanners blaring constantly whenever you have to talk to one of these people?  I hate having to alternately have to shout over and hear through the noise of their scanners.  If you're talking to someone, turn it off or turn it well down.

Well, I'm not a ham but my scanner is going constantly.  But I do have the common sense and decency to switch it to mute when talking on the phone or if I have a visitor. And it's also on mute if I'm watching TV.

The only time it's switched off is when the Lady Cop is here. She has made it abundantly clear that the last thing she want's to hear when off duty is radio calls. I guess I can't blame her. 

 

[Cerebus]

Well, the discrete ADC design has got from this simulation:



to this, running on actual hardware:



Proof that all this test gear does actually get used, even if it is to design more test gear! 

It's fudged at the moment - a corner of the FPGA is pretending to be the analogue electronics to the rest of the FPGA - but at least it's wiggling the right wires in the right way and responding to feedback from the faked current steering, integrator and comparator. Looks like the next step is a dive into PCB design and see if I can get a board before the usual "Can't get anything done because it's Christmas". I love Christmas, but it's a right pain in the arse that what can normally happen by "next week" suddenly becomes "2nd week of January" as soon as Christmas looms.

Added to the whole "nearly Christmas" thing the PCB design which would normally be a one to two day job will stretch to three or four because for this baby I'm going to want to add in a lot of carefully thought out test points, built-in Z₀ probes and logic analyser takeoff points becuase I know that if I don't this board will be hell to debug, and if I do add all that it'll probably all work first time rendering all that work pointless. Sheesh, the price we pay for Murphy!

It doesn't trigger reliably at the moment, which suggests that I've got a timing issues that doesn't show up in simulation (where it works perfectly every time) but only on real hardware. Still, it's on an FPGA so I can safely move to "solder state" and debug the timing issue once I'm on a PCB with some minimum guarantees about signal integrity rather than the tangle of wires it is at the moment. Vis:

[Cerebus]

It doesn't trigger reliably at the moment, ...

Ha! Found it! 

Trigger pulse was too narrow and was probably failing a setup or hold time.  That's the thing with FPGAs, you have to leave timing that you'd normally calaculate in the lap of the gods because you often don't even have setup and hold timing data for the internal FFs.

I'm quite surprised that the STM32 talking to the FPGA was capable of producing too narrow a pulse as there are two RTOS calls involved in setting and clearing the trigger pin. Put a delay loop in as a POC, which works, and I can fix the substantive problem with a different style of synchroniser as the trigger pulse goes into the FPGA - that's for tomorrow as with that bug detection it's bedtime.

[vk6zgo]

I'm going to throw this out there since I know many of you have encountered ham radio operators.  And in this case, an aspiring ham radio operator.

What's the deal with the scanners blaring constantly whenever you have to talk to one of these people?  I hate having to alternately have to shout over and hear through the noise of their scanners.  If you're talking to someone, turn it off or turn it well down.

I do ham radio like I do messing with TE----- in my spare time (a rapidly diminishing asset!)
Thus, I very seldom have any kind of radio blaring in the background.

Other people have their TV set blaring when they answer the phone, & still others lose concentration when in a face to face conversation, distracted by something on their "smartphone".