Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

I juss' figgered he wudd on Furkbook... everybody like dat when dey on Furkbook.

mnem

[xrunner]

You want hair, here I am in ~1974. Looks like I got a rare signal on the old Radio Shack DX-150 shortwave receiver. A horrible thing to use but I didn't know any better so to me it was as good as the best military receiver. 

Also check the hip leather watch band!

[BU508A]

 

[bd139]

That is exactly how my mother used to do my hair but with a plastic mixing bowl. This was also after drinking gin usually so made for some interesting hair cuts 

[GreyWoolfe]

Some good news here. My daily insulin routine is having some positive effects. Since upping the daily shot from 10 units to 15 units my fasting blood sugar has come down dramatically. Tuesday was 120mg/dL. Yesterday 113mg/dL. This morning 109mg/dL. For a non-diabetic should ideally be 100mg/dL or less. But anything under 120mg/dL is considered "acceptable". So I'm getting there. 

Good news.

A word of caution if I may, and I'll add that you've said nothing to make me suspect you're doing this, so treat this as a public service announcement and not directed at you. A doctor I was talking to once said that it was "Important to remember to treat the patient or disease, not treat the numbers". With any physiological process that can spit out numbers ostensibly characterising how 'good' or 'bad' things are there's a tendency for both doctors and patients (also public health authorities and policy makers) to fixate on the numbers, sometimes to the detriment of the person/people being treated.

In a perfectly healthy individual you can expect the numbers to bounce around from day to day and it's important to remember that you're measuring a noisy process, with the analytical equivalent of 2 or 3 digit DVM, and also that the 'normal' figures are derived from population norms that are themselves noisy and sometimes from such small sample sizes that it'd be embarrassing to be caught relying on them. Thus the practical difference between 109mg/dL and 'normal' is a bit like the practical difference between 5.25V on a rail and the nominal 5V figure. Sure, if you've got a handy adjustment and an accurate enough meter you'd probably adjust that rail to 5.00V but you don't actually have to. As long as the device is working well 5.25V is fine, and similarly with disease processes that have 'numbers', as long as the patient is healthy that's the important thing, not that the 'numbers' are spot on. On the particular subject of diabetes I wonder what effect happens  in the US where 3 digit mg/dL figures are used, versus places that use mmol/L figures that are usually expressed as two digits - that 109 mg/dL would come out as 6.1 mmol/L. Does it predispose people to inappropriate over-precision because there are 3 rather than 2 digits in the number?

With diabetes we're quite lucky that HbA1c figures give a much better picture than regular blood sugar readings, so those are the numbers to pay attention to. Of course with HbA1c being a long term measurement they are much harder to tune in (long phase delay in the control loop). Beware doctors who inappropriately obsess on short term measures of physiology (like instantaneous blood sugar measurements) versus long term ones (like HbA1c) and/or the actual health of their patients. For the avoidance of doubt there are, of course, values of short term measurements that need treating as medical emergencies, it's quite right to react to 'numbers' that are so statistically significantly off the norm that they indicate an immediate or immanent problem.

Everything you stated is absolutely true. I fully realize and understand blood sugar numbers are a moving target and constantly change. My whole point in buckling down and checking it on a daily basis is because over the past 6 months my A1C has been climbing. That's the number that's most important when treating and monitoring diabetes. And now that I am on insulin I need to find that point where over an average period of time my instantaneous blood sugar numbers show a steady decline to what is considered "normal". And that will result in an A1C number to shows that I am successfully treating and managing the condition. I have seen what uncontrolled diabetes does to a person and it ain't pretty.

I have also.  My son-in-law doesn't even attempt to manage his diabetes.  He has diabetic retinopathy and has had multiple laser treatments and surgery on his eyes.  He has diabetic neuropathy, he has lost 2 toes and almost lost a third.  He has had stents in his legs because he has basically no blood flow to his feet.  Unfortunately, I believe that if he doesn't change his ways, and I see zero effort even with begging and pleading from our daughter, in a couple of years he will probably be on permanent disability and within 5 years, probably be dead.  Mrs GreyWoolfe and I hope for a miracle but I remain doubtful.

I track my numbers everyday like Papa Smurf, even keeping a spreadsheet of my numbers.  I am now consistently under 100 mg/dl, whether I check morning or night as I alternate.  This morning I was 94 mg/dl.  More importantly, due to my healthy eating habits, my A1C came down from 6.9 to 5.1.  My primary care has me do blood work every 6 months and part of the panel is fasting blood sugar and A1C.  She is very pleased with my progress, to say the least.

[Vince]

Got a palette parcel from Germany this morning, thanks BU ! 

My 1uF 630V yellow axial caps are here, I can now complete the recap of my Tek 180A Time Mark Generator, the last final cap it was missing 

.. but turns out I got a lot more than just caps !!

- A bunch of these vintage pF caps in a metal can cap, transistory looking

- A bunch of military grade µA709AHM vintage precision op-maps in a cool vintage TO39 looking can 

- x4 long nice quality test leads, x2 red and x2 black, love these, I can never have enough of them.

- A little battery powered thermometer with a long thin flexible probe... that will be perfect to monitor the temperature in my fridge, from the outside. No need to open the fridge anymore to check the thermometer I put in it. By the way my fridge timer still works perfectly, it's a winner ! No EMI problems Cap'tain  !    It's a winner, I think it's ready for patenting ! 

- A hollow-state Tektronix Mug ! OK now I can feel the pressure coming... I feel the obligation to soon resume restoration work on my old Tek scopes...

Thanks a million BU, I appreciate all of this very much !!! 

[Robert763]

@Vince
A small TE care package form the UK just went in the post.

[BU508A]

- A bunch of military grade µA709AHM vintage precision op-maps in a cool vintage TO39 looking can 

You are welcome Vince, my pleasure. 

I recommend to check a bit more closely all those LM709 ... 

[mnementh]

- A bunch of military grade µA709AHM vintage precision op-maps in a cool vintage TO39 looking can 

You are welcome Vince, my pleasure. 

I recommend to check a bit more closely all those LM709 ... 

Thanks, BU for again being all that TEA is supposed to be about.   

EDIT: Did you slip a thermistor in there for V...?

mnem

[Vince]

Wow looks beautiful.. must have cost a fortune to assemble/manufacture ! 

If you like to watch pictures of semiconductor dies, then you should check out Richis Lab.

Here is an example from a Motorola 2N3055 transistor. What I really like about those pictures about power transistors is that one can see the barrier layer, because Richi is driving them in reverse mode and then the B-E diode becomes a Zener.



B-E diode working as a Zener at 300mA:

OK just sacrificed a 2N3055 and tried the same experiment. Doesn't work, die doesn't light up. VERY disappointed !     

Maybe it can't be seen with the naked eye, or it needs a long exposure time to gather sufficient light, or it requires a special version of the 2N3055, I don't know.
All I can say it that it didn't work on my particular transistor, and I now have one less 2N3055, he died for nothing. I am sad now.

I have to correct myself regarding the B-E diode is becoming a Zener. This is only partially true. The main effect is, that the B-E diode is working in avalanche mode. Depending on the materials being used, the produced light can be anything from IR to blue (SiC for example). Richi states, that the light can be visible to the naked eye, but it is mostly very dim. So, if you want to see this effect, it is perhaps a good idea to sit in a dark room for about 10 minutes so your eyes can adapt to the darkness and then try again.

Here is a discussion about the glowing effect of B-E diodes working in avalanche mode:
https://www.eevblog.com/forum/projects/transistors-die-pictures/msg3068740/#msg3068740

Wow, a thread dedicated to the subject, with beautiful pictures at that ! So my little shitty experiment is pointless then ! 

.. but I did it ANYWAY, because nothing beats doing it YOURSELF, and seeing it with your own eyes !! 

So I sacrificed yet another  2N3055 transistor... this time I took my time to hack saw it, exercising as much care as I could in a hope I would not destroy / damage the pins/bonding wires inside 
So instead of trying to cut the very top of the cap, instead I cut it at the very bottom, because there is much more clearance with the pins, so less chances that the blade might catch them.
Also I removed the blade from the saw frame, and cut on pull, so I could control the blade better. It was a success, for the first time, 4th attempt, I now have a TO3 that survived its convertible top conversion !

That means I don't need to stick my SMD probes directly onto the die any more, which was hardly reliable and convenient, I experienced...
Now I can just use grabbers to connect to the outside pins, wire that to the power supply, and I have both hands free to play with the controls on the power supply, and hold the camera steady with both hands. It's getting luxurious can't you see ? !
Thanks to this much better controlled testing environment, I was able to achieve success, look at that !!!   

The B-E junction in reverse starts breaking down / conducting at about 15.2 Volts. To get this picture I put 1.2 Amp into it, Voltage rose to 18V or so. I closed the window shutters to make the lab dark. Then opened the shutters half way and noticed the camera could still pick-up the glow, using the highest ISO setting, 6400.

As you can see the glow does not spread across the entirety of the "path" / squiggly line, for some reason I am way too stupid to explain.
Upping the current has zero effect on this " issue " whatsoever. Past one ampere, upping the current does not increase the glow, it stays where it is.  Past 2 amps, suddenly the glow disappeared and was reduced to one single tiny dot in a corner of the die. I thought OK I blew it, too much current, had to happen... but then I lowered the current limit on the power supply and the glow came back ! It's still alive and going, this transistor is a warrior !!!     Everyone should have a 2N3055 in his life !

Wow that was a cool and fun experiment ! Everyone should do that ! 

Think I will archive the pics and my test results/notes on it, it was that cool.

EDIT : The experiment cost me more than a few TO3 pacakges... cost me also one of my Hirschmann long grabbers ! Package got so hot during the experiment that it badly melted the tip of the insulation of the black grabber !! 

[mnementh]

@Vince   A small TE care package form the UK just went in the post.

Awesome! This is what TEA is supposed to be about... TEAddicts helping TEAddicts fulfill their addiction. 

Thank you, Robert! 

mnem
 

[mnementh]

Wow that was a cool and fun experiment ! Everyone should do that !  Think I will archive the pics and my test results/notes on it, it was that cool.

EDIT : The experiment cost me more than a few TO3... cost me also one of my Hirschmann long grabbers ! Package got so hot during the experiment that it badly melted the tip of the insulation of the black grabber !! 

Hooray for "testing to failure mode" experimentation... 

But... am I the only one here who noticed that it kindof looks like Vince's glowing 2N3055 is flipping us the bird...? 

mnem
Vince is lit AF.  

[Vince]

@Vince
A small TE care package form the UK just went in the post.

 

[Vince]

- A bunch of military grade µA709AHM vintage precision op-maps in a cool vintage TO39 looking can 

You are welcome Vince, my pleasure. 

I recommend to check a bit more closely all those LM709 ... 

Oh I see.... 10 out of 12 have a tiny little red dot painted on top of the can... I guess that means they were all factory rejects, they don't work ?! 

But two of them sport a yellow dot rather than red. Yellow is better then red... not quite green, but better than red, so maybe that means they partially work.... they meet some but not all of their specs.

Will wire a few of them on a bread board anyway to see if there is life left in them, you never know, might still be good enough to blink an LED or something ! 

[GreyWoolfe]

New York airshow. 3 years ago. Most recent pix I have. Hair present then. Hair present now.

The chemotherapy has had a strange effect on my hair.  The hair on my head, mustache and goatee has thinned but I have lost most of my body hair.  Hopefully, it will grow back when the chemo is done.

[m k]

Some TE discussion for a change:

This ad https://www.tradera.com/item/340198/542487628/spectrumalalysator-tektronix-7613 purports to offer a 7613 mainframe with a 7L3 SA. It's being sold as faulty, and will need repair. Some of the powered up pics are possible clues to the fault, but I know next to nothing about the 7000 series.  Seller states "HV present, but the rest does not work so well. For starters, a liberal amount of contact cleaner will be required." The price is interesting, even if it will go up 100x, but I'd like some opinions on possible faults, so I know if it's worth fighting for.

I was inquiring if anybody around is about to visit Drottningholm.

BTW,
no wonder I have problems repairing things.
I'm measuring a CPU board but looking front panel schematics, again.
Bigger screen and closer would probably help.

BTW2,
HP 85053B Electronic Equipment Maintenance Kit in Vegas
https://eu.ironplanet.com/for-sale/Ty%C3%B6kalut-Nevada/6400148

[AVGresponding]

I picked up the new screen for the Agilent U1273A from the Post Office yesterday, and would have made a post but so many things went wrong I just ran out of time and energy.

Serpentine belt jumped off the Inshitnia again, in the Co-Op car park, haven't even looked under the bonnet yet, took the TiTTy to work today instead. I could also feel a cold coming on, courtesy of a work colleague, and I duly remembered to call him a cunt this morning.



The new screen fitted perfectly, and works perfectly; however, the meter does not work perfectly, there's a problem with the front end, volts (both dc and ac), ohms, diode check, all overread by 2-4%, drifting down from 4 to 2 over time.
Capacitance, ac and dc current are all spot on, so I'm (hopefully) ruling out the ADC, and suspect something in the V/Ω protection circuitry.





Then I couldn't upload any pics, as my phone decided to refuse to talk to my PC.

I have to say, this thing feels cheap compared with my U1401B, which rivals a Fluke 27 for heft. The rotary switch is not as good as its stablemate either, not even worthy of comparison with a Fluke or Brymen. Better than my Tektronix 912 though.



With 4 MOVs PTCs you'd expect it to be quite electrically robust. Not sure what the heatshrink covered parts are. Interesting that they went to the trouble of putting the range hybrid in a shielding can. Naturally, since it's a reasonably modern HPAK, schematics/service manual are unobtainium, so I'll have to do it the hard way.

[bd139]

Good to know the screen cleaned up.

Worth cleaning it properly with isopropyl around the front end before doing anything. All sorts of leakage paths around there due to the high impedance. I had similar issues with a couple of DMMs which were resolved by cleaning.

[AVGresponding]

Good to know the screen cleaned up.

Worth cleaning it properly with isopropyl around the front end before doing anything. All sorts of leakage paths around there due to the high impedance. I had similar issues with a couple of DMMs which were resolved by cleaning.

It's probably worth a punt; whoever was in here before me left debris on the inside of the screen, so cleanliness obviously wasn't uppermost in their mind.

[mnementh]

...BTW2,
HP 85053B Electronic Equipment Maintenance Kit in Vegas
https://eu.ironplanet.com/for-sale/Ty%C3%B6kalut-Nevada/6400148

Product Overview

The Keysight 85053B (Agilent) verification kit has a 3.5 mm connector and covers a frequency range of 300 kHz to 26.5 GHz. The 85053B supports the Agilent 8510A, 8510B, 8510C, 8719A - 8719ES, 8720A - 8720ES, and PNA series of network analyzers. This kit includes a 7.5 cm airline, stepped impedance airline, 20 dB and 40 dB attenuators.

Verification kits are used to verify that a network analyzer is operating within its specified performance.

List $10193.27 American Oil Notes each.

mnem
 

[mnementh]

I picked up the new screen for the Agilent U1273A from the Post Office yesterday, and would have made a post but so many things went wrong I just ran out of time and energy.

Serpentine belt jumped off the Inshitnia again, in the Co-Op car park, haven't even looked under the bonnet yet, took the TiTTy to work today instead. I could also feel a cold coming on, courtesy of a work colleague, and I duly remembered to call him a cunt this morning.



...The new screen fitted perfectly, and works perfectly; however, the meter does not work perfectly, there's a problem with the front end, volts (both dc and ac), ohms, diode check, all overread by 2-4%, drifting down from 4 to 2 over time.
Capacitance, ac and dc current are all spot on, so I'm (hopefully) ruling out the ADC, and suspect something in the V/Ω protection circuitry...

*chimes in* "Sick cunt stay home!" 

Too bad about the "more than one fail" on this one man... that new screen looks nipply. 

Any evidence of g'rilla abuse...? ie, maybe this unit was bashed together of faulty bits from repaired units?

Seems that's almost the only thing I find on fleaBay lately... 

mnem
 

[TERRA Operative]

As an Australian, I approve of this foul language.

[DC1MC]

Are you a Tek lover ? Are you German ? Do you have germoney ? Then the answer is this:

https://www.ebay-kleinanzeigen.de/s-anzeige/kennlinienschreiber-tektronix/2111929863-168-13379

[Vince]

Wow, only 800 Euros ?!   

That's freaking cheap !  Last one I saw here in Frog land was 2 years ago and guy wanted 2,500 Euros for it, "as is", not powered up, super crusty and no test fixture.

Still, 800 Euros is way more than I can afford... and I prefer my 575 anyway !! 

[mnementh]

Good to know the screen cleaned up.

Worth cleaning it properly with isopropyl around the front end before doing anything. All sorts of leakage paths around there due to the high impedance. I had similar issues with a couple of DMMs which were resolved by cleaning.

It's probably worth a punt; whoever was in here before me left debris on the inside of the screen, so cleanliness obviously wasn't uppermost in their mind.

What we need for things like this is a mouse-sized pressure-washer with a fitting that you can screw a quart of IPA onto and let 'er rip... 

mnem
What...? Pesky labels, silkscreen, or solder mask gotchoo down...? Now they're GONE!!!