Test Equipment Anonymous (TEA) group therapy thread

[med6753]

Yes, I am awake at 0230 hours local time. I'll putter around for a while and go back to bed. I mentioned last week that after starting low dose insulin that my fasting blood sugar was reduced but still slightly above the ideal mark. Got permission and blessing from doc to increase that dose from 10 units to 15 units and track it.

Next TE project? A few minor things and then beyond that I have no clue.  I can hear the sirens of Ebay calling my name.     

The second HV unit is still around, I think ...   

Yes, it is. But I need a break from jackassing heavy boat anchors for a while. 

[med6753]

This must be the hint the boss tossed in our laps yesterday.

https://www.eevblog.com/forum/testgear/new-next-gen-tektronix-scope/

[Cubdriver]

Edit to keep on topic since we've advanced a page....



I popped the cover off of the 4800A and took a few more pictures of it.  Normal HP construction of the era - well laid out and easy to access, no surprises.
Top view of open chassis:


The oscillator circuitry resides inside the shielded box in the front right corner:


Other pics at: https://pmanning.smugmug.com/Electronics/HP-4800A-Vector-Impedance-Meter  (Crappy iPad pics, at some point I'll take better ones with the DSLR)

-Pat

[capt bullshot]

Good news from the "Fun with (Ice-)TEA dept" on now it works wednesday:

Thanks to the tip by TERRA Operative, I have now access to the calibration menu at the WT1600.
To calibrate (adjust to be correct) the shunt input, one needs a 60Hz current source at various currents from 50mA to 5A. 50mA to 2A (1.99999A indeed) does the Fluke 5100B. For 5A, I went to the basement and fetched this amplifier from a storage shelf, along with the 1mOhm shunt resistor.



Using these, the Tek clamp on CT and two 34401A, I was able transfer the 2A from Fluke to 5A through this amplifier and the 33120A generator. Now the WT1600 shows pretty good results, and nicely agrees with the second Fluke 5101B. This gives at least some confidence into this non-traceable home lab calibration.
I didn't touch the calibration of the voltage and BNC input ranges, since I found them good enough in spec at former tests.

[capt bullshot]

I popped the cover off of the 4800A and took a few more pictures of it.  Normal HP construction of the era - well laid out and easy to access, no surprises.

Regarding "well laid out and easy to access" - I would have liked to see and show pics of the central logic board of the WT1600 power meter. Don't expect anything rocket science there, but at least which main CPU and DSP was used. But Yokogawa did a quite standard Yokogawa job in making this board as inaccessible as they could do.

[Cubdriver]

*wail* <--- siren

Not exactly. More like these deadly creatures. 

Looks like a redhead front and center - you're toast!   

-Pat

[tautech]

This must be the hint the boss tossed in our laps yesterday.

https://www.eevblog.com/forum/testgear/new-next-gen-tektronix-scope/

Yeah and we'd get more info about these from Alan (w2aew) than Dave's prepared to leak. 

[BU508A]

*wail* <--- siren

Not exactly. More like these deadly creatures. 

What, if Saskia had those guys in mind? 

[srb1954]

I popped the cover off of the 4800A and took a few more pictures of it.  Normal HP construction of the era - well laid out and easy to access, no surprises.
Top view of open chassis:



Other pics at: https://pmanning.smugmug.com/Electronics/HP-4800A-Vector-Impedance-Meter  (Crappy iPad pics, at some point I'll take better ones with the DSLR)

-Pat

Are those PCBs only tin coated or is just the lighting/camera that make them look that way?

On my 4800A the PCBs are fully gold plated as was normal for HP equipment of that era.

[Specmaster]

The perversity of the Universe tends to the maximum.

No, this time, you're just whining. Sorry to blunt it to you, but this is so completely the wrong tree to bark up against.

Seatbelts save lives. STFU and buckle up. End.

I've always worn seat belts. Right from the very first day I got behind the wheel with a learner's permit. Back then cars were lap belts only and you had to fish them out from under the seat because no one used them.

When I learned to drive, there was no such thing as seatbelts.

[med6753]

*wail* <--- siren

Not exactly. More like these deadly creatures. 

What, if Saskia had those guys in mind? 

Not a fan of raggae.

[med6753]

The perversity of the Universe tends to the maximum.

No, this time, you're just whining. Sorry to blunt it to you, but this is so completely the wrong tree to bark up against.

Seatbelts save lives. STFU and buckle up. End.

I've always worn seat belts. Right from the very first day I got behind the wheel with a learner's permit. Back then cars were lap belts only and you had to fish them out from under the seat because no one used them.

When I learned to drive, there was no such thing as seatbelts.

All the cars I owned or drove were 1964 or newer. I think lap belts were pretty much standard equipment starting in 1963 or 1964. 

[Vince]

What is this " Linear Technology " branded calculator sitting on top of the TE patient ?

Some rebranded off the shelf (which one ?) calculator, or did LT ask Casio or TI or whoever, to make them a custom calculator with their own specs / features / looks ??

[Vince]

Next TE project? A few minor things and then beyond that I have no clue.  I can hear the sirens of Ebay calling my name.     

I thought you said the purchase of your new A/C unit meant you were broke and no TE budget for you for the next few months ?! 

[capt bullshot]

What is this " Linear Technology " branded calculator sitting on top of the TE patient ?

Swag from embedded world fair some years ago

Some rebranded off the shelf (which one ?) calculator, or did LT ask Casio or TI or whoever, to make them a custom calculator with their own specs / features / looks ??

No, it's an off the shelf one with no special features. Not even one of the big brands, it says "abacus" on its back side. Rather a cheap look and feel knockoff from a Casio.



BTW: it has an "poke with a needle type" reset button on it's backside, and one needs to use that button sometimes WTF?

[med6753]

Next TE project? A few minor things and then beyond that I have no clue.  I can hear the sirens of Ebay calling my name.     

I thought you said the purchase of your new A/C unit meant you were broke and no TE budget for you for the next few months ?! 

By the end of this month the TE budget will be fully recovered. However, now that the new A/C unit is installed and has seen use already I suspect my electric bill might chew up that recovery. 

[bd139]

Ok an actual TE post. Black Star Jupiter 2010 arrived. Looks in good condition, appears to actually work fine although I have nothing to check that available at the moment.

Outside:



Insides view 1:



Insides view 2:



Very standard design akin to Thurlby / TTi and it is of the same heritage.

[bd139]

What is this " Linear Technology " branded calculator sitting on top of the TE patient ?

Swag from embedded world fair some years ago

Some rebranded off the shelf (which one ?) calculator, or did LT ask Casio or TI or whoever, to make them a custom calculator with their own specs / features / looks ??

No, it's an off the shelf one with no special features. Not even one of the big brands, it says "abacus" on its back side. Rather a cheap look and feel knockoff from a Casio.



BTW: it has an "poke with a needle type" reset button on it's backside, and one needs to use that button sometimes WTF?

These are made by a company called Kinpo: https://www.kinpo.com.tw/en-US/products/consumer-electronics

The TI, Casio, basic HP, generic ones are all made using the same hardware platform and software these days. The only thing that is customised is the plastic and branding. The basic OS is pretty nice though to be honest.

BUT as you will find out they are generally garbage hardware quality. I actually had to run out yesterday and grab a replacement Casio FX991EX because the 4 and integral button stopped working on my eldest's calculator.

[mnementh]

Since I burned my fingers with the evil raspberries (I do not like them...) this time I ask before.

Are you happy with the ESP32 based boards? Is the ESP32 running stable for you? Can be used in production?´
Many thanks.

I’ve stayed away after reading horror stories. Things like crashes when you write to flash during interrupts, undocumented behaviour and the ADC sucking complete balls. However there are very few SoC at that level which have the out of box features you might need and you can actually still get the things.

Ergo I’d put the engineering hat on, write your feature requirements down, do a KT decision analysis against that and STM32 and see what comes out.

As for seatbelts, I only wear them on Mondays, Thursdays and occasionally Sundays  *

_{* oh the power of carefully misstating positions}

I don't wear a belt on my seat anymore unless I'm going out to the store, a restaurant or some appointment. The rest of the time I'm either wearing shorts or it's a pants-free day. 

mnem
I am not my pants. No, I am not your pants, either.

[mnementh]

*wail* <--- siren

  Not exactly. More like these deadly creatures. 

Needs more redheads.

mnem
Too much is never enough...

[mnementh]

This must be the hint the boss tossed in our laps yesterday.

https://www.eevblog.com/forum/testgear/new-next-gen-tektronix-scope/

So Tek is releasing a MICSIG...? Okay... way to be a decade late to the party...

Hopefully their implementation will be more robust, tho.

mnem
 

[BU508A]

Ok an actual TE post. Black Star Jupiter 2010 arrived. Looks in good condition, appears to actually work fine although I have nothing to check that available at the moment.

Outside:



Insides view 1:



Insides view 2:



Very standard design akin to Thurlby / TTi and it is of the same heritage.

You are having now a good camera, now you need better lighting. 

[bd139]

You are having now a good camera, now you need better lighting. 

Hahaha so true. I actually have a couple of LED soft boxes and tripods here but they are packed away 

[Vince]

Hmmm.... looks like I have some kind of A/C problem like Papa Smurf. It's my fridge though.... it's getting hot here and the fridge is having a hard time keeping my supplies fresh. Thermometer I shoved inside says 15°C when a fridge is supposed to be 6°C....
Been that way for years to be honest. But this time I decided to tackle it.

The compressor is not running all the time. It comes and goes. So it does not look like a refrigerant leak, more like a dodgy thermostat, good news then, might be fixable.

So I disconnected the thermostat and bypassed it with a jumper wire at its connector. Compressor starts right away, yeah... it's good.

So needs a new thermostat... or maybe not ? Look at the back of it, there is a resistor crimped across two of the 3 terminals the thermostat carries.
That resistor looks overheated and its body and terminations are all cracked, brrr...
Colour bands on it suggest it's supposed to be 47K at 2%. A precision resistor in a freaking fridge ?!

I have no idea what it's for, but it sure doesn't look in good health. When I measure it in situ I get a short, though I don't know it it's actually died shorted, or if that resistor might be wired in // with some contact inside the thermostat, that might be closed.

Old man, who used to teach / train white good service/repair technicians before he retired 20 years ago, says he might still have some compatible thermostat at home, cool (but he lives 150kms away...). If not, he says a new thermostat costs only 20 Euros so not the end of the world ! I mean the fridge is probably almost 30 years old now, so a 20 Euros thermostat after 25+ years, to make it go another 10 years probably... I am not complaining at all !
Yes, I am not exactly the kind of person that fuels the consumerism and planned obsolescence business....

OK so let's attend to that resistor now. Hopefully it's all that's wrong and I don't even need a new thermostat !


Electronics : 47K 2% resistor. Trouble shooting.  First order closed-loop temperature control system. Sounds more techy that way eh ?!  )
TE : Fluke 11 DMM.
Supplies : jumper wire.

[GreyWoolfe]

Mandatory seat belt use became Federal law once, in 1974. Every new passenger vehicle sold in the USA had a starter interlock to prevent you from starting the car unless the driver and front passenger buckled their seat belt. The public outcry was so loud that the interlock was removed starting in 1975. And the interlock on the 1974 cars was easy to defeat.

As far as I know every state now requires mandatory seat belt use but there is no interlock. Just the reminder light on the dash and the nanny buzzer.

Here if Flori-DUH, we have lit signs on the sides of the roads that say, click it or ticket.  They must have paid someone a crap pot of money to come up with that.