Test Equipment Anonymous (TEA) group therapy thread

[Saskia]

what had happened ?
In the morning Hubby went to a cardiologist to take a stress ECG which was cancelled due to his physical condition. He needs to have a stress ECG to get his stomach surgery to fix internal bleeding, and he needs to be off blood thinners to go ahead with the surgery ... It's only been a year since his 3rd heart attack, so he is still on blood thinners, and surgery is a problem. As is covid vaccination btw ...

Anyway, the stress ECG was cancelled, a blood sample was drawn and forwarded to the lab. He did a normal ECG and was sent home.
at about 3:45 pm the cardiologist called to tell him that they found troponin in the blood sample which is an indicator of heart muscle tissue death, which in turn is an indicator of an ongoing heart attack and that he called the rescue services, Hubby should grab his stuff as the Chest Pain Unit in the next larger hospital was already informed.

Which he did. I informed by boss about a family emergency and told him that I was off for the rest of the day, the ambulance came by, as did the emergency physician and they lugged him into the Mayence university hospital CPU. (which does not allow relatives due to Covid ...)
There they continuously monitored Troponin levels plus the other markers and did their ECG. Fortunately they could not confirm the initial diagnosis, found problems with his potassium levels (which would explain his blood pressure problems) and told him that he really needed to get his stomach and esophagus fixed.

He is back home, and it seems that the decision to move to a place about 10 km away from the next large hospital complex was foresighted and prudent ...

It is not a good sign if you have to choose the place you want to live at with vicinity to emergency services as the main criteria ...

 

That's interesting. So Hubby was off for a stress ECG? Has he been exercising in anticipation of this? The reason I ask is that Troponin is a cardiac specific marker for cardiac muscle damage, not necessarily cardiac muscle cell death and you can find raised levels in people who've been getting cardiovascular exercise that is vigorous enough to promote cardiac muscle remodelling*. So its possible to get a false positive suggesting heart damage when in fact it's in the process of getting stronger.

I'm not suggesting that this is what has happened here but it's worth being aware of and drawing the medic's attention to the possibility if Hubby has a "type A" personality and has been doing the physical equivalent of swotting up before an exam.

They used to use a less specific test for Creatine Phosphokinase for the same purpose and you can find elevated CPK levels from skeletal muscle as well as from cardiac muscle. That's lead to some panics where athletes have been having routine tests and someone just saw the test numbers and didn't take all the circumstances into account. It happened to me in my fifties when I'd been hospitalised because of an asthma attack. They'd run a large panel of blood tests, more than were necessary because of why I was there (I suspect they do that in patients "of a certain age" in case they can catch something before it becomes a problem while they've got ahold of you), and found raised CPK levels. Lucky I was clued up enough to divert them from unnecessarily referring me to cardiology on top of having thoracic consultants buzz around me. They tend just to see the patient in front of them who is currently as weak as a kitten  and forget that the same patient the day before may have been perfectly capable of indulging in exercise tough enough to floor a thirty year old (in my case some heavyweight interval training on the bike) before an allergic response dumped them in a hospital bed.

* 
Rifai N, Douglas PS, O'Toole M, Rimm E, Ginsburg GS (April 1999). "Cardiac troponin T and I, echocardiographic [correction of electrocardiographic] wall motion analyses, and ejection fractions in athletes participating in the Hawaii Ironman Triathlon". Am. J. Cardiol. 83 (7): 1085–9. doi:10.1016/S0002-9149(99)00020-X. PMID 10190525.

Neumayr G, Gaenzer H, Pfister R, et al. (February 2001). "Plasma levels of cardiac troponin I after prolonged strenuous endurance exercise". Am. J. Cardiol. 87 (3): 369–71, A10. doi:10.1016/S0002-9149(00)01382-5. PMID 11165984.

Urhausen A, Scharhag J, Herrmann M, Kindermann W (September 2004). "Clinical significance of increased cardiac troponins T and I in participants of ultra-endurance events". Am. J. Cardiol. 94 (5): 696–8. doi:10.1016/j.amjcard.2004.05.050. PMID 15342317.

This is understood however due to his internal bleeding (esophagus / stomach hernia) there is no strenuous exercise for him, he is too week to carry 10 kg downstairs. The stress ECG was scheduled to see if he can in fact survive the esophagus/ stomach surgery. He has a history of cardiac events including at least 3 heart attacks, so when the cardiologist saw enhanced troponin levels he immediately suspected a heart attack and put out the alarm.
 

[Cerebus]

Foreground - I got a present from Daniel Bogdanoff today, along with a note to the effect of  "We haven't forgotten about you, a factory order for your 'scope is in, we've been hit by chipageddon as well".

Background - 53132A OCXO cooling off along with the "Taaaantssss!" to get the option 012 board back to factory condition.

[ch_scr]

Look, the dmtd-wannabe sprouted an additional comperator 
Bonus footage of the upcycled / 3d-printed wire pen and the fugly upside of the pcb with the wire links included

[ch_scr]

Did you take the heatshrink off Q3/Q5? according to the drawing they should be in a sleeve an in contact with that white ceramic washer (which is BeO so don't break it). If they are not in good therml contact you may have issues.

I pulled all the cards and took photos  so I could do a visual inspection.     Looks to me like Q3/Q5 were glued together!    I've never seen silicon grease harden like this but I don't often see 40 year old heat sink compound.

That is a very interesting way to couple two transistors thermally, have not seen that before. Not sure it's necessarily a very good way, with the heat having to travel along the case lids. Must have been good enough, cheap & small! I prefer the "Al-block with two trannys side-by-side" that needs more pcb space but I'd guess it gives (way) better coupling.

[nixiefreqq]

Did you take the heatshrink off Q3/Q5? according to the drawing they should be in a sleeve an in contact with that white ceramic washer (which is BeO so don't break it). If they are not in good therml contact you may have issues.

I pulled all the cards and took photos  so I could do a visual inspection.     Looks to me like Q3/Q5 were glued together!    I've never seen silicon grease harden like this but I don't often see 40 year old heat sink compound.

be very very very careful with that BeO washer.

it is not something you want to scratch, grind, file or break.   when BeO dust is inhaled it actually can kill you.


https://www.hse.gov.uk/pubns/indg311.pdf


edit  some of the german made hp pulse generators have BeO insulators in them too.  (the ones with slide switches).  use caution with them also.

[Cerebus]

Evil tant replaced.



I had a bit of a 'moment' while doing this. Replaced cap, put everything back together, left case off and powered up to run the self-test. Self-test OK, put the case on, powered up - self-test front end fail. Oh fuck!

Long story short, the secondary input cable that runs from the front panel channel 1 input to the rear panel channel 1 input had moved over a couple of inches to under the power supply - that apparently could generate enough spurious pickup to cause it to fail self-test. So, HP 53132A and 53131A owners beware, the routing of the rear input cables (if fitted) is critical and they are not secured in any fashion.

[Cerebus]

In other news. The two PCB orders I put in to JLCPCB yesterday are progressing. The cheap-and-cheerful board that fits the cheapest option (two layer, 1.6mm, green solder mask, HASL finish) is already in electrical test. The more costly board, differentiated only by being ENiG finished rather than HASL and submitted first, has only got as far as etching. Proof that picking any option other than the bog standard means that your board has to wait for enough other boards with the same process parameters to make up a panel.

We all knew that of course, but it's interesting to see the proof working out in practice. I wouldn't be surprised to see the standard cheapo board get dispatched before the end of the day while the other is going to be another day at least.

[Specmaster]

Just a quick update, the TTi SM630 scopemaster (its a scopemeter with 20Mhz scope, DMM, frequency counter and a timer) and with it came Feedback FG601 signal generator .01Hz to 1 Mhz have arrived all safe and sound, well-packed and quick test shows that they are both working fine. They are both in very good condition cosmetically and the SM630 even still has its carrying handle which also doubles as a tilting bail.
Took a quick squiss inside, the SM630 looks as good as the day it left the production line back in 1994, no problems inside at all, even the back-up battery measures good, but this will be replaced. It also came with 6 C cells, NiCd, RS ones that were probably fitted when supplied as the unit came from RS when new. Surprisingly, these have not leaked in these years,  dodged a bullet there. Plugged it in, powered up OK and seems to be working just fine and is in calibration, both as a DMM (autoranger) and as a scope, connected to my Heathkit IG-4505 scope calibrator it is spot, both in timebase, frequency and voltage. However, as I feared, the screen backlight is very dim, so that needs addressing if possible.

A similar tale to be told with the FG601, good cosmetic condition, both need a spot of cleaning, checked output, and it is also spot on and double-checked this on my Fluke PM3390B in digital mode, so all is good there as well. Took a look inside, and it only has 4 electrolytics, all made by Sprague and I checked these and what do you know, almost bang on, slightly higher in capacitance but all with very low ESR readings, so they can stay, and this thing was made in 1974, the same year that the UK introduced nationwide postal codes. So like bd, I have nothing really to do with these, they are useable straight off the bat, apart from backlight and the memory battery to replace.

Photos to follow later when I have done the shopping and cleared enough of the clutter off the bench to enable photos to be taken 

[bd139]

Sounds good - looking forward to that one.

As I'm off work this afternoon I completed the TOPS1 repair. Rotten transistor loom removed



New one made up. Sorry about the lacing - it's the wrong size for the job (round .8mm vs should be flat .5mm) but it'll have to do:



NOS transistors in situ with proper mounting hardware. Ignore the mess - that's just where I got rid of the oxide and some crappy camera angle damage amplification. Quick check for shorts from collector to chassis (done that before!)



Reinstalled and resoldered



Calibration in progress - all working!



All done



Now in that horrible state where everything works properly again 

[Neomys Sapiens]

Actually that reminds me. I have been staring at the internal circuits of ICs, particularly LM723s and looking for ways to make things do things that they shouldn't. I think I'm onto a way to abuse the LM723 in a way as yet unattempted. I will detail it if it doesn't turn into a dead end.

Also ALD1105 datasheet is an interesting read http://www.aldinc.com/pdf/ALD1105.pdf

ALD makes several interesting chips. But no matter under which company ID I placed my request, I have never been able to wrangle samples out of them. 

[med6753]

The Type 547 back in the penalty box until next week sometime. As a consolation brought up the Type 535A in the hopes that SOMEDAY the Type 547 will do the same without burning the house down. I did some quick checking of the +100V supply before buttoning it up. I did a resistance check to ground and it's 1.4K which is normal and the same freaking problem I had weeks ago. No short indicated with power off.  The supply is capable of approx 400ma. I installed a 500ma quick blow fuse in line and it did NOT blow.  The 6080 regulator tube that red plated will be trashed. I won't risk it. I have a spare and luckily they are common and not all that expensive. With the 87 I did a quick diode check of the vertical output transistors thinking that they may be cause. Nope, they checked OK. 

So what's the plan from here? Well, it's obvious I'm going to have to connect the external 100V supply again in the hopes that the defective part will finally reveal itself. It's almost like this scope needs a catheter like I did. Note, did. I'm good now. My suspicions lie with something with the name "Germanium" in them but we'll see. I'm going to disconnect the vertical output transistors while doing this work just as a safe guard. I hate covering the same ground again but I guess I have no choice. 

Oh and the Type 1A1 plug-in has been removed in favor of the Type 1A2. The Type 1A1 showed some of the same issues I saw when it was installed in the Type 535A. So it will go into the repair cue to fix at a later date. 

     

[med6753]

Sounds good - looking forward to that one.

As I'm off work this afternoon I completed the TOPS1 repair. Rotten transistor loom removed



New one made up. Sorry about the lacing - it's the wrong size for the job (round .8mm vs should be flat .5mm) but it'll have to do:



NOS transistors in situ with proper mounting hardware. Ignore the mess - that's just where I got rid of the oxide and some crappy camera angle damage amplification. Quick check for shorts from collector to chassis (done that before!)



Reinstalled and resoldered



Calibration in progress - all working!



All done



Now in that horrible state where everything works properly again 

Well if you're that bored wanna fix a 547 for me? 

[bd139]

If you buy the plane tickets 

[med6753]

If you buy the plane tickets 

How about if I loan you my canoe? 

[bd139]

How about if I loan you my canoe? 

I think you can go piss up a rope 

[med6753]

How about if I loan you my canoe? 

I think you can go piss up a rope 

Touche. LMAO.

[ch_scr]

...

Now in that horrible state where everything works properly again 

You haven't checked thoroughly enough then 

[Neomys Sapiens]

Found on Ebay.de - several multi-output lab power supplies:

https://www.ebay.de/itm/384311745066

https://www.ebay.de/itm/184979882953

and other interesting PSUs:

https://www.ebay.de/itm/334097543578

https://www.ebay.de/itm/174868289104

in the UK is a Farnell AP70-30 with whopping 30A/70V and interesting displays:
https://www.ebay.de/itm/224555646393 (Link is from Ebay.de)

and a FARNELL ET30/2:
https://www.ebay.de/itm/234009427179 (as above)

as well as a Farnell 11E301BT
https://www.ebay.de/itm/265244187067 (same)

and a Topward TPS-4000
https://www.ebay.de/itm/174866746070 (again)

and in the US a KEPCO ABC 25-4DM at solanotraders

[mnementh]

My thoughts are with you, I know that although my Mother had been very ill for a number of years, and in and out of hospital on a number of occasions, it still came as a hard thing to accept when during my daily visits to her in hospital, I was called in to see the consultant, and he uttered those words that really choked me up, that he was sending her back home into the hands of her carers for her end of life, it chilled me to the very core of my body. Once she was at home, the end came very quickly indeed. She got her last wish   

Mine went out how she wanted to. She was drinking a G&T and chilling in the arm chair with a book. Went to sleep and didn't wake up.

Book in question: https://en.wikipedia.org/wiki/Blood_Meridian

When I die I want to go peacefully in my sleep, just like my grandfather. Not screaming in terror like his passengers...

mnem
 

[mnementh]

what had happened ?
In the morning Hubby went to a cardiologist to take a stress ECG which was cancelled due to his physical condition. He needs to have a stress ECG to get his stomach surgery to fix internal bleeding, and he needs to be off blood thinners to go ahead with the surgery ... It's only been a year since his 3rd heart attack, so he is still on blood thinners, and surgery is a problem. As is covid vaccination btw ...

Anyway, the stress ECG was cancelled, a blood sample was drawn and forwarded to the lab. He did a normal ECG and was sent home.
at about 3:45 pm the cardiologist called to tell him that they found troponin in the blood sample which is an indicator of heart muscle tissue death, which in turn is an indicator of an ongoing heart attack and that he called the rescue services, Hubby should grab his stuff as the Chest Pain Unit in the next larger hospital was already informed.

Which he did. I informed by boss about a family emergency and told him that I was off for the rest of the day, the ambulance came by, as did the emergency physician and they lugged him into the Mayence university hospital CPU. (which does not allow relatives due to Covid ...)
There they continuously monitored Troponin levels plus the other markers and did their ECG. Fortunately they could not confirm the initial diagnosis, found problems with his potassium levels (which would explain his blood pressure problems) and told him that he really needed to get his stomach and esophagus fixed.

He is back home, and it seems that the decision to move to a place about 10 km away from the next large hospital complex was foresighted and prudent ...

It is not a good sign if you have to choose the place you want to live at with vicinity to emergency services as the main criteria ...

 

That's interesting. So Hubby was off for a stress ECG? Has he been exercising in anticipation of this? The reason I ask is that Troponin is a cardiac specific marker for cardiac muscle damage, not necessarily cardiac muscle cell death and you can find raised levels in people who've been getting cardiovascular exercise that is vigorous enough to promote cardiac muscle remodelling*. So its possible to get a false positive suggesting heart damage when in fact it's in the process of getting stronger.

I'm not suggesting that this is what has happened here but it's worth being aware of and drawing the medic's attention to the possibility if Hubby has a "type A" personality and has been doing the physical equivalent of swotting up before an exam.

They used to use a less specific test for Creatine Phosphokinase for the same purpose and you can find elevated CPK levels from skeletal muscle as well as from cardiac muscle. That's lead to some panics where athletes have been having routine tests and someone just saw the test numbers and didn't take all the circumstances into account. It happened to me in my fifties when I'd been hospitalised because of an asthma attack. They'd run a large panel of blood tests, more than were necessary because of why I was there (I suspect they do that in patients "of a certain age" in case they can catch something before it becomes a problem while they've got ahold of you), and found raised CPK levels. Lucky I was clued up enough to divert them from unnecessarily referring me to cardiology on top of having thoracic consultants buzz around me. They tend just to see the patient in front of them who is currently as weak as a kitten  and forget that the same patient the day before may have been perfectly capable of indulging in exercise tough enough to floor a thirty year old (in my case some heavyweight interval training on the bike) before an allergic response dumped them in a hospital bed.

* 
Rifai N, Douglas PS, O'Toole M, Rimm E, Ginsburg GS (April 1999). "Cardiac troponin T and I, echocardiographic [correction of electrocardiographic] wall motion analyses, and ejection fractions in athletes participating in the Hawaii Ironman Triathlon". Am. J. Cardiol. 83 (7): 1085–9. doi:10.1016/S0002-9149(99)00020-X. PMID 10190525.

Neumayr G, Gaenzer H, Pfister R, et al. (February 2001). "Plasma levels of cardiac troponin I after prolonged strenuous endurance exercise". Am. J. Cardiol. 87 (3): 369–71, A10. doi:10.1016/S0002-9149(00)01382-5. PMID 11165984.

Urhausen A, Scharhag J, Herrmann M, Kindermann W (September 2004). "Clinical significance of increased cardiac troponins T and I in participants of ultra-endurance events". Am. J. Cardiol. 94 (5): 696–8. doi:10.1016/j.amjcard.2004.05.050. PMID 15342317.

This is understood however due to his internal bleeding (esophagus / stomach hernia) there is no strenuous exercise for him, he is too week to carry 10 kg downstairs. The stress ECG was scheduled to see if he can in fact survive the esophagus/ stomach surgery. He has a history of cardiac events including at least 3 heart attacks, so when the cardiologist saw enhanced troponin levels he immediately suspected a heart attack and put out the alarm.

Ummm... *gulp* Any word yet on how bad the damage was...? I find myself also wondering why the stress EKG was canceled... but probably don't want to know the answer. 

mnem
*crosses claws, toes, wings and tail hoping for a hopeful prognosis*

[mnementh]

As I'm off work this afternoon I completed the TOPS1 repair. Rotten transistor loom removed... New one made up. Sorry about the lacing - it's the wrong size for the job (round .8mm vs should be flat .5mm) but it'll have to do...   NOS transistors in situ with proper mounting hardware. Ignore the mess - that's just where I got rid of the oxide and some crappy camera angle damage amplification. Quick check for shorts from collector to chassis (done that before!)

   (SNIP)   Now in that horrible state where everything works properly again 

You really should have splurged on the right stuff, instead of stealing the lacing from Cerebus' combat boots... 

mnem
 

[mnementh]

Quick E3630A teardown. Went looking to see which variety of RIFA it has in it.  Looking towards front panel board. All analogue apart from the TC14433 ADCs...

Oooooh... lookit all those adjustment pots to go Grape-Ape on!!!

mnem

[bd139]

As I'm off work this afternoon I completed the TOPS1 repair. Rotten transistor loom removed... New one made up. Sorry about the lacing - it's the wrong size for the job (round .8mm vs should be flat .5mm) but it'll have to do...   NOS transistors in situ with proper mounting hardware. Ignore the mess - that's just where I got rid of the oxide and some crappy camera angle damage amplification. Quick check for shorts from collector to chassis (done that before!)

   (SNIP)   Now in that horrible state where everything works properly again 

You really should have splurged on the right stuff, instead of stealing the lacing from Cerebus' combat boots... 

mnem
 

Yeah indeed. This is waxed cotton lacing. Designed for something a little larger 

[mnementh]

As I'm off work this afternoon I completed the TOPS1 repair. Rotten transistor loom removed... New one made up. Sorry about the lacing - it's the wrong size for the job (round .8mm vs should be flat .5mm) but it'll have to do...   NOS transistors in situ with proper mounting hardware. Ignore the mess - that's just where I got rid of the oxide and some crappy camera angle damage amplification. Quick check for shorts from collector to chassis (done that before!)

   (SNIP)   Now in that horrible state where everything works properly again 

You really should have splurged on the right stuff, instead of stealing the lacing from Cerebus' combat boots... 

mnem
 

Yeah indeed. This is waxed cotton lacing. Designed for something a little larger 

Hey, you use what you have to sometimes.  I may have... I say may have... used insulation stripped off of Cat5 conductors in a pinch to get a receiver on the sale table for the weekend.

mnem
 

[mnementh]

yes.

mnem
 

Heh-heh...

Sorry... there has been an unexpected delay caused by Amazon taking forever to deliver some A27 batteries. and now, due to a mishap during fitment/design of part B, I have to wait til Friday for some pogo pins before I can use it anyways.

I'll update once I have something meaningful accomplished... this is actually TEA related for a fucking change.

mnem

Ugghh... all that waiting on the A27 batteries so I could finalize the design... then I find they can't handle (well, at least the cheapies I got off Amazon) the current draw. So I run down to the local Dollarama for a A23 like I should've done yesterday... and now of course a redesign to fit the larger battery. 

mnem