Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

I have this. It works, most of the time. If not it's old fashion liquid flux and braid.

You just can't go wrong with a proper powered desoldering station, single-handed operation, loads of sucking, changeable tips zero rebound impact on the pcb etc therefore less damage done. No need for braid and it will pull all the solder out of plated through holes as well, less chance of damage to pads etc and will pads completely intact and flat.

[Ice-Tea]

IT GOES UP TO 11! 

[med6753]

IT GOES UP TO 11! 

Are they perhaps equal signs? 

[Ice-Tea]

Well, dunno what it stands for. But it's OL on the DMM

[capt bullshot]

IT GOES UP TO 11! 

Meh.

This one does minus one to ten

[Peter_O]

The HP6653A



has the output connectors directly on the pcb as the smaller HP66xxA power supplies.



To maintain the current of 15A max, they are two beefy brackets with two screws through the board each.
But nevertheless any stress on the cables moves the corner of the PCB and the brackets might get bumped when this 25 kg thing is moved around.

Luckily I've some 3D printers and so I printed this quick and dirty solution:

[factory]

ed.
If you find cheaper in the Euro zone, please share ! 

https://www.eleshop.nl/zd-8915-desoldeerstation.html?gclid=CjwKCAjw6dmSBhBkEiwA_W-EoGsWCirBt7LrNpIwoMLgYsc1zN4I4Mch59MlUqi2JkTq9zfrfflv-BoCr3YQAvD_BwE

I'll collect my cookie later today

Sorry, no cookie for you, because you people told me to search for " ProsKit SS-331 ", and yours is a different brand and model, albeit the same product obviously, so how could I possibly find it ?! 

You do however get a big thank you. 

99 Euros that's my budget for a decent tool like this. Plus this one has a pale blue that's similar to my old Weller iron, so it will blend in just nicely. I am not a fan of the modern trend of flashy bright colours, and weird looking childish toy-ish color schemes and user interfaces... Rigol and Hakko come to mind.

So, thanks a bunch for the link, I am saving it for later 

We had an older Duratool rebrand of the cheapo desoldering station (aka radio jammer) for a couple of years at work, after the Weller died, the Duratool lasted way longer than I expected.  But was disposed of when we downsized to one bench, we kept the Pace & Hakko.
Current version of the Duratool trash can filler here. 
https://cpc.farnell.com/duratool/d03324/desoldering-rework-station/dp/SD0229287?CMP=CPC-ebooks-BulkMar22

David

[Robert763]

IT GOES UP TO 11! 

Are they perhaps equal signs? 

Nope. I have a number of "Decade" boxes that have  11 or 12 steps, 0 to 10 ("X" for on a ESI DB877) or 0 to 11.
Makes best use of 30 degree index, 12W switches at least.....

[Cubdriver]

-Pat

[factory]

(Not sure off the top of my head what the 5216A uses as a frequency standard, but given that it's about 51 years old I'm impressed!  I suppose it can be considered well aged at this point in time.)

The 5221A, IIRC, uses mains frequency; it certainly came in two options, 50 and 60 Hz. Mine is spot on, compared to meters steered by my Meinberg GPS. 

The 5216, according to PRC68.com has, in some revisions, an 1MHz Bliley.

However, reading from the source, [hp] journal #8 from 1967, the time base in the 5216 is 10MHz. I did remember the clock source in the 5221 correctly, though.

My 5216A is an older version with 10MHz crystal (used in prefix 748 & below according to the manual), the main board is different too, as it has a divider to give the 1MHz output on the back.

Looking at the later version (from prefix 916) the 1MHz Bliley is just a crystal, again no fancy temp compensation or ovenized rubbish. 

David

[factory]

Honest comment from the seller: "They all turned on last week but one didn't turn on this week. Have been stored under a tarpaulin". Not the only things, from the look of it.

You forget this gem, again from that seller.
https://www.ebay.co.uk/itm/165415965228

I deliberately forget that gem, as I was bidding on it, just hope both feet are on it*, also would keep the meter frame as I've had too many damaged in various ways, also need the inside cover for my other 3406A, the rest probably belongs in the trash, if it's as badly corroded on the inside, the same as the outside. 

*never seem to be able to find this case size at low prices to borrow feet from.

David

[Cubdriver]

And the little HP badge.  Funny that they're often missing on otherwise pristine instruments, and yet here this dumpster fire is still sporting the one it came with.

-Pat

[tggzzz]

Honest comment from the seller: "They all turned on last week but one didn't turn on this week. Have been stored under a tarpaulin". Not the only things, from the look of it.

You forget this gem, again from that seller.
https://www.ebay.co.uk/itm/165415965228

I deliberately forget that gem, as I was bidding on it, just hope both feet are on it*, also would keep the meter frame as I've had too many damaged in various ways, also need the inside cover for my other 3406A, the rest probably belongs in the trash, if it's as badly corroded on the inside, the same as the outside. 

*never seem to be able to find this case size at low prices to borrow feet from.

I hope you got it; £16 for the 3rd bid seems reasonable.

And the little HP badge.  Funny that they're often missing on otherwise pristine instruments, and yet here this dumpster fire is still sporting the one it came with.

I have one of those badges on a name badge. You've made me wonder how much I could flog it for

[Vince]

Nixie DMM repair update

OK, been redoing the solder joints on the comparator board, sucking all the solder with my trusty solder sucker, a good one from Japan which I paid a fortune for at Farnell 5 years ago. 15 Euros or something IIRC. Sucks really well, rarely ever clogs and if it does, it's quick and effortless to open it up : opens from the top, just turn it a 1/8 turn and that's all, you can pull the guts out of it, remove solder, put it back in , quick twist to lock it, and back to work. Takes less than 30 seconds when I am lazy.
But there is recoil of course, so solder wick is sometimes used instead. Well, often... no recoil, so no stressing my wrist, no noise.. it's more "calm".. I like wick... but it's expensive. The solder sucker let's you suck lots of solder over and over again, for free. So I use both equally often I find.

Anyway, so I sucked all the joints from the front end of both comparator : S1 to S4 and S7. Circled in red on the board, and highlighted in yellow on the schematic.

When I went over the joints for the transistors, surprise... what is that.... at first it looked like the pad got lifted, all of them, and were dish shaped, towards me. Like a cup.. weird. Then I realized what I was seeing was some tiny metal insert they used. They installed the hollow insert into the PCB, then the legs of the transistors go inside the insert. The "cup" shape" goes to the solder side.
so I though hmm... another variable to the joint equation... I don't like variables. Maybe these inserts are causing my dodgy connection problem... so I removed them all. All 30 of them. Took a while, a bitch to grab while heating up the joint with the iron.

So now at least I could see the pad I was soldering too, so greater confidence in my new joints...

Also redid the joints of the two card edge connectors on that board. Two 12 way connectors.

Then plug the board back into the meter and fire it up, crossing fingers.... what would I get ? Eh ? I ask ?...

Offset is now -2375mV !!!!  YES !!! I mean, the bigger the better no ?! No ? 
Fuck me... I broke it ! 

HOWEVER.... it's not all bad !

I know... 2.5V offset is terrible...  BUT... there is GOOD news in there, yes there is, I swear ! 

Before you throw your arms in the air yelling how incompetent I am, that I should not be allowed anywhere near a soldering iron... listen to what I have to say for my defense :

The problem we were trying to solve was twofold :

1) There was this "thermal looking" effect : the offset would be super high from cold, then plummet within a few seconds, then slow down then take 20 minutes to slowly converge to 60mV or something, whereas the good board doesn't do that at all. From cold, it gives zero offset right off the bat and stays there.

2) Then once settled at 60mV, it would more and more often jump suddenly to zero, what it should be, hence exhibiting the symptoms of a bad connection somewhere.


Well..... now that I have redone these joints, OK, I do get a crazy, stupid weird sky high... offset. OK. BUT... it is STABLE !
Power up, I get 2350mV. A few seconds later... still the same. 5 minutes later, 30 minutes later.... still the same, doesn't drop neither quickly nor slowly !
Actually all it does is slowly fluctuate inside of a narrow window, between say 2350 and 2400mV, and stays inside that window.

It's been running for at least an hour now, and still solid.

So... I would venture into pretending that I somehow FIXED the two problems we trying to tackle, eh ?? 

So now I need to find why the offset is stupid high now.

Two possibilities I guess :

1) The heat of the soldering iron damaged one of the transistors.

2) I put the transistors in the wrong spot... S3 I paid attention, I desoldered/resoldered them one at a time.
Then the 4 of the diff pairs, they didn't get removed because the metal bracket and glue is holding them all together.
However the other row of 4 trannies (S4 and S7) circled in yellow on the board), right next to the row with the black bracket... these are not held by anything, so when I removed the metal inserts, they fell off the board by themselves...
I put them all on the bench, in the same sequence, so I could put them back in order.
Problem is... when I went to resolder them, I had forgotten from WHICH END of the row I was supposed to start inserting them ! 
So my guess is, maybe, that this row of 4 trannies is front to back... so I need to desolder them and put them back in reverse order...

Stay tuned...

EDIT : well now I think of it, these particular trannies should be interchangeable, they are not doing anything fancy... so... hopes are not high on this... problem must lie somewhere else... but I have no idea where... 

[Specmaster]

Nixie DMM repair update

OK, been redoing the solder joints on the comparator board, sucking all the solder with my trusty solder sucker, a good one from Japan which I paid a fortune for at Farnell 5 years ago. 15 Euros or something IIRC. Sucks really well, rarely ever clogs and if it does, it's quick and effortless to open it up : opens from the top, just turn it a 1/8 turn and that's all, you can pull the guts out of it, remove solder, put it back in , quick twist to lock it, and back to work. Takes less than 30 seconds when I am lazy.
But there is recoil of course, so solder wick is sometimes used instead. Well, often... no recoil, so no stressing my wrist, no noise.. it's more "calm".. I like wick... but it's expensive. The solder sucker let's you suck lots of solder over and over again, for free. So I use both equally often I find.

Anyway, so I sucked all the joints from the front end of both comparator : S1 to S4 and S7. Circled in red on the board, and highlighted in yellow on the schematic.

When I went over the joints for the transistors, surprise... what is that.... at first it looked like the pad got lifted, all of them, and were dish shaped, towards me. Like a cup.. weird. Then I realized what I was seeing was some tiny metal insert they used. They installed the hollow insert into the PCB, then the legs of the transistors go inside the insert. The "cup" shape" goes to the solder side.
so I though hmm... another variable to the joint equation... I don't like variables. Maybe these inserts are causing my dodgy connection problem... so I removed them all. All 30 of them. Took a while, a bitch to grab while heating up the joint with the iron.

So now at least I could see the pad I was soldering too, so greater confidence in my new joints...

Also redid the joints of the two card edge connectors on that board. Two 12 way connectors.

Then plug the board back into the meter and fire it up, crossing fingers.... what would I get ? Eh ? I ask ?...

Offset is now -2375mV !!!!  YES !!! I mean, the bigger the better no ?! No ? 
Fuck me... I broke it ! 

HOWEVER.... it's not all bad !

I know... 2.5V offset is terrible...  BUT... there is GOOD news in there, yes there is, I swear ! 

Before you throw your arms in the air yelling how incompetent I am, that I should not be allowed anywhere near a soldering iron... listen to what I have to say for my defense :

The problem we were trying to solve was twofold :

1) There was this "thermal looking" effect : the offset would be super high from cold, then plummet within a few seconds, then slow down then take 20 minutes to slowly converge to 60mV or something, whereas the good board doesn't do that at all. From cold, it gives zero offset right off the bat and stays there.

2) Then once settled at 60mV, it would more and more often jump suddenly to zero, what it should be, hence exhibiting the symptoms of a bad connection somewhere.


Well..... now that I have redone these joints, OK, I do get a crazy, stupid weird sky high... offset. OK. BUT... it is STABLE !
Power up, I get 2350mV. A few seconds later... still the same. 5 minutes later, 30 minutes later.... still the same, doesn't drop neither quickly nor slowly !
Actually all it does is slowly fluctuate inside of a narrow window, between say 2350 and 2400mV, and stays inside that window.

It's been running for at least an hour now, and still solid.

So... I would venture into pretending that I somehow FIXED the two problems we trying to tackle, eh ?? 

So now I need to find why the offset is stupid high now.

Two possibilities I guess :

1) The heat of the soldering iron damaged one of the transistors.

2) I put the transistors in the wrong spot... S3 I paid attention, I desoldered/resoldered them one at a time.
Then the 4 of the diff pairs, they didn't get removed because the metal bracket and glue is holding them all together.
However the other row of 4 trannies (S4 and S7) circled in yellow on the board), right next to the row with the black bracket... these are not held by anything, so when I removed the metal inserts, they fell off the board by themselves...
I put them all on the bench, in the same sequence, so I could put them back in order.
Problem is... when I went to resolder them, I had forgotten from WHICH END of the row I was supposed to start inserting them ! 
So my guess is, maybe, that this row of 4 trannies is front to back... so I need to desolder them and put them back in reverse order...

Stay tuned...

EDIT : well now I think of it, these particular trannies should be interchangeable, they are not doing anything fancy... so... hopes are not high on this... problem must lie somewhere else... but I have no idea where... 

If they are in the wrong order, it will make a hell of a difference, double check them again. You have 3 NPN and 1 PNP transistors there and different HFE's as well of course voltage ratings  etc.

[TERRA Operative]

Good thing you are documenting with photos, Vince!

Back in this post, you have your answer on the order of the transistors, looks like you got it right.

https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg4115050/#msg4115050

[dew]

Greetings,

Tektronix 2465BDM for sale
and some
Tektronix Cameras

I'm not interested, but I guess somebody here might be

[Neomys Sapiens]

The outlook for my Soar pen multimeter, which I had to exclude from the last round of DMMCheck testing, because it did not work at all despite full button cells, is rather bad. While I had assumed that it suffers from a corrosion issue, I was mislead by the green of the PCB getting reflected on the shining bright contacts.
Except..except..where is that rear half of the middle contact, which is connecting the two cells in series? It is a contact spring which is formed from sheetmetal and separated in the mid vertically. Then it goes over a plastic partition, which is molded into the shell. The rear half of that spring has broken off exactly at the apex of the partition. Unfortunately, springs of any kind are about the worst parts for improvised repair. No matter how diligently you cut and bend, suddenly the material isn't a spring anymore.  Of course, heat treatment could restore this, but this transcends the improvisation part. It is still laying in the open and nearby, as to make me think about it more. Would be a loss of a device which served me long and well and I would need a new one for my most compact kit. Meh.

[mnementh]

Sounds to me like a candidate for a Lixx upgrade. 

mnem
 

[mansaxel]

P.S. I have also used my latest tool for the first time. This is a pair of cable shears made by KNIPEX, type 95 05 165. It surely makes a clean cut.
https://www.knipex.de/sites/default/files/Product%20data%20sheet%20EN%2095%2005%20165.pdf

Cable shears are very addictive. I use them all the time if I'm working on power cable or coax. They simply cut, none of that side cutter battle. A light hand can use them to good effect to remove outer sheath on multi core cable or things like NYM-J et c as well. I've got a not-name US made pair that I've had for like 20 years. Not perfect, but still always comes out first when I'm doing bigger work.

[AVGresponding]

P.S. I have also used my latest tool for the first time. This is a pair of cable shears made by KNIPEX, type 95 05 165. It surely makes a clean cut.
https://www.knipex.de/sites/default/files/Product%20data%20sheet%20EN%2095%2005%20165.pdf

Cable shears are very addictive. I use them all the time if I'm working on power cable or coax. They simply cut, none of that side cutter battle. A light hand can use them to good effect to remove outer sheath on multi core cable or things like NYM-J et c as well. I've got a not-name US made pair that I've had for like 20 years. Not perfect, but still always comes out first when I'm doing bigger work.

The Japanese Steel that I bought are holding up well so far, well worth the £18 price. Used them when I had to tinker with some PVC-covered MICC yesterday, after one of the apprentices core drilled through it and put the existing fire alarm system into fault. This was just after he'd core drilled through the lighting circuit in the room we were working in...   

[Cubdriver]

P.S. I have also used my latest tool for the first time. This is a pair of cable shears made by KNIPEX, type 95 05 165. It surely makes a clean cut.
https://www.knipex.de/sites/default/files/Product%20data%20sheet%20EN%2095%2005%20165.pdf

Cable shears are very addictive. I use them all the time if I'm working on power cable or coax. They simply cut, none of that side cutter battle. A light hand can use them to good effect to remove outer sheath on multi core cable or things like NYM-J et c as well. I've got a not-name US made pair that I've had for like 20 years. Not perfect, but still always comes out first when I'm doing bigger work.

The Japanese Steel that I bought are holding up well so far, well worth the £18 price. Used them when I had to tinker with some PVC-covered MICC yesterday, after one of the apprentices core drilled through it and put the existing fire alarm system into fault. This was just after he'd core drilled through the lighting circuit in the room we were working in...   

I’m thinking you should probably get that drill out of his hands before he gets a hat trick.

-Pat

[david77]

...



...

Does anybody else feel deep discomfort when seeing components strewn around the PCB at random angles, or is it just me?

[Cubdriver]

It’s not just you.  We’re so spoiled these days with computer aided layout, nicely routed traces and neatly placed components.  Oh, and silkscreens.  Yay for silkscreens.

-Pat

[Cubdriver]

(Not sure off the top of my head what the 5216A uses as a frequency standard, but given that it's about 51 years old I'm impressed!  I suppose it can be considered well aged at this point in time.)

The 5221A, IIRC, uses mains frequency; it certainly came in two options, 50 and 60 Hz. Mine is spot on, compared to meters steered by my Meinberg GPS. 

The 5216, according to PRC68.com has, in some revisions, an 1MHz Bliley.

However, reading from the source, [hp] journal #8 from 1967, the time base in the 5216 is 10MHz. I did remember the clock source in the 5221 correctly, though.

My 5216A is an older version with 10MHz crystal (used in prefix 748 & below according to the manual), the main board is different too, as it has a divider to give the 1MHz output on the back.

Looking at the later version (from prefix 916) the 1MHz Bliley is just a crystal, again no fancy temp compensation or ovenized rubbish. 

David

My older 5216A has the old school crystal.


The newer one I was using the other day (mid 1971 production, 1040 engineering rev) has the newer Bliley crystal.


I haven’t had time to set up the Lucent rubidium standard yet, but will try to do so today and see how close things really are.  Everything had been on for a few hours when I took that picture the other day, so they’d had time to stabilize.

-Pat (on the bright side, I’ve managed to resist time nuttery thus far…)