Test Equipment Anonymous (TEA) group therapy thread

[worsthorse]

The next project. This represents all the can electrolytic capacitors in the 535A. Looks overwhelming at first pass but I'm going to do it in stages. Intention is the simply bypass the original cans and leave them in place. And use terminal strips to mount new capacitors under the chassis. But in at least 2 areas that won't be possible and the cans will have to be removed and the new capacitors installed top side.

So all I have to do now is get the courage to start. Moving the monster around to get to the capacitors is a royal PITA. But if I want longevity in the old beast it has to be done.
 

Go for it!

I'll make you a deal. I will set aside the TM500 plugins and crack open the TDS520 when you start this one. 

I am looking at about 100 SMD caps to remove, two or three boards that have to be meticulously cleaned, two hundred pads to be checked and tinned, then all those caps to be installed.  Assuming of course, that I don't find any trace or via damage right off the bat.   

[Sam Spastic]

At least you know your Weston cell and voltmeter have drifted the same amount.  Very nice!

Weston cells only drift when they are used up or damaged. Otherwise, the output voltage is always exactly what you expect once you compensate for temperature. That's what makes it such a useful reference, even today.

The fact that any noise on the cell's output is far below my ability to measure it makes it doubly useful. Instead of wondering if the meter is stable when watching a 10V reference bounce around +/- 20μV, you connect the Weston cell and as long as the temperature remains stable, a good meter just shows the same voltage, without any variation.

Saturated Weston cells drift with temperature and are relatively fragile, but can have a very long life.

Unsaturated Weston cells are more stable with temperature and are less fragile, so they were often used inside equipment. But they had a finite lifetime, and I believe you are unlikely to find a working one nowadays.

I have 3. One is in a Leeds & Northrop Millivolt Potentiometer. One is an Epply Standard Cell from 1948.  One is a new in box Weston. All have reasonable outputs but the L&N is at the extreme end of calibration.

I am NOT a voltnut. I am NOT a voltnut. I am NOT a voltnut.

[tggzzz]

At least you know your Weston cell and voltmeter have drifted the same amount.  Very nice!

Weston cells only drift when they are used up or damaged. Otherwise, the output voltage is always exactly what you expect once you compensate for temperature. That's what makes it such a useful reference, even today.

The fact that any noise on the cell's output is far below my ability to measure it makes it doubly useful. Instead of wondering if the meter is stable when watching a 10V reference bounce around +/- 20μV, you connect the Weston cell and as long as the temperature remains stable, a good meter just shows the same voltage, without any variation.

Saturated Weston cells drift with temperature and are relatively fragile, but can have a very long life.

Unsaturated Weston cells are more stable with temperature and are less fragile, so they were often used inside equipment. But they had a finite lifetime, and I believe you are unlikely to find a working one nowadays.

I have 3. One is in a Leeds & Northrop Millivolt Potentiometer. One is an Epply Standard Cell from 1948.  One is a new in box Weston. All have reasonable outputs but the L&N is at the extreme end of calibration.

I am NOT a voltnut. I am NOT a voltnut. I am NOT a voltnut.

And guess what just popped into my inbox <sigh>...

From: "Pete Manfre" <...>
Date: Thu, 6 Feb 2020 12:55:39 -0500
Subject: [test-equip-trader] Standard cells

I have 8 standard cells. See picture below.   All tested (on very very high
impedance unit).   All working well.   $30 each shipped CONUS Priority mail
insured.

They mostly look unsaturated, which fits with the "test-equip-trader". Many are Eppley Labs devices.

[med6753]

The next project. This represents all the can electrolytic capacitors in the 535A. Looks overwhelming at first pass but I'm going to do it in stages. Intention is the simply bypass the original cans and leave them in place. And use terminal strips to mount new capacitors under the chassis. But in at least 2 areas that won't be possible and the cans will have to be removed and the new capacitors installed top side.

So all I have to do now is get the courage to start. Moving the monster around to get to the capacitors is a royal PITA. But if I want longevity in the old beast it has to be done.
 

Go for it!

I'll make you a deal. I will set aside the TM500 plugins and crack open the TDS520 when you start this one. 

I am looking at about 100 SMD caps to remove, two or three boards that have to be meticulously cleaned, two hundred pads to be checked and tinned, then all those caps to be installed.  Assuming of course, that I don't find any trace or via damage right off the bat.   

Yea, I've seen videos on the SMD tant replacement on a TDS520 or similar. No thank you!   

I think by Saturday I will have built enough courage to start the 535A. I'll let you know. 

[nfmax]

You can never be too thin, too rich, or have too many function generators (I just got the second freebie 33120A going)

[capt bullshot]

[
This is probably due to the NTFS backing of Cygwin on windows more than anything. NTFS stores all tiny little files inside the MFT which is write blocked. So every time you write a pissy little file out (compiling and VCS stuff does this lots!) it has to lock the MFT, extend and then write the file, then unlock it. This causes MFT contention which reduces the effective IOPS to the disk to virtually nothing even if the thing is fast. In fact mechanical disks can suck less because the kernel has time to order the writes while it's waiting for the disk to go round!
...

Thanks, I didn't go into NTFS that far, but one can always notice Windoze slowing down to a crawling turtle's speed when copying a large set of rather small files, no matter if one uses that Exploder thing or cmdline (e.g. xcopy or robocopy).
BTW, the old machine from work flies like hell with this compile job if natively booted into debian (don't tell our IT dept, but I think that'll be my workaround, using the new windoze box just as the frontend for Outlock and Orifice)

[bd139]

If you need to do that it’s quicker to mount it on a Linux machine and copy the files 

[Cubdriver]

This was posted in the Tek Facebook group. Who is this? It HAS to be someone in here. At least with the accent narrow it down to a Brit.

Fess up!! 

https://www.youtube.com/watch?v=wL1N0_vJZTo&feature=youtu.be&fbclid=IwAR3_jSdLqBhTfCAnlLyb3cNYG_keI4BC9A_PNoLZxpDViFHFtkP9J4_fZKQ

ok, i confess.

it is me.

recognized myself by the two hp 5327 nixie counters in the background.

wait a second......i don't own a rush t shirt (or any tek equipment).  maybe it IS someone else?

We know it's not you - there are only two of them!!     (Though I must admit I was pleased to see them!)

-Pat

[Cubdriver]

The next project. This represents all the can electrolytic capacitors in the 535A. Looks overwhelming at first pass but I'm going to do it in stages. Intention is the simply bypass the original cans and leave them in place. And use terminal strips to mount new capacitors under the chassis. But in at least 2 areas that won't be possible and the cans will have to be removed and the new capacitors installed top side.

So all I have to do now is get the courage to start. Moving the monster around to get to the capacitors is a royal PITA. But if I want longevity in the old beast it has to be done.

   

C'mon, man - if you're gonna do it, do it right!



https://pmanning.smugmug.com/Electronics/Restuffing-can-electrolytics  (Start at image 66 for the second and more successful go-round)

-Pat

[Mr. Scram]

You can never be too thin, too rich, or have too many function generators (I just got the second freebie 33120A going) (Attachment Link)

Now you're just showing off!  How did you end up with a second freebie 33120A?

[worsthorse]

The next project. This represents all the can electrolytic capacitors in the 535A. Looks overwhelming at first pass but I'm going to do it in stages. Intention is the simply bypass the original cans and leave them in place. And use terminal strips to mount new capacitors under the chassis. But in at least 2 areas that won't be possible and the cans will have to be removed and the new capacitors installed top side.

So all I have to do now is get the courage to start. Moving the monster around to get to the capacitors is a royal PITA. But if I want longevity in the old beast it has to be done.
 

Go for it!

I'll make you a deal. I will set aside the TM500 plugins and crack open the TDS520 when you start this one. 

I am looking at about 100 SMD caps to remove, two or three boards that have to be meticulously cleaned, two hundred pads to be checked and tinned, then all those caps to be installed.  Assuming of course, that I don't find any trace or via damage right off the bat.   

Yea, I've seen videos on the SMD tant replacement on a TDS520 or similar. No thank you!   

I think by Saturday I will have built enough courage to start the 535A. I'll let you know. 

 

Yeah, I didn't really know what I was getting into when I got it.  Then I watched the videos on replacing tants. It doesn't look difficult so much as really tedious, at least until I have to start looking for damaged traces, etc. 

[SilverSolder]

[...]

If you want to compile stuff on Windows, do it in a VM with ext4.

[...]

Not sure I understand how that would work, you can't mount an ext4 file system in Windows...   can you?

[med6753]

The next project. This represents all the can electrolytic capacitors in the 535A. Looks overwhelming at first pass but I'm going to do it in stages. Intention is the simply bypass the original cans and leave them in place. And use terminal strips to mount new capacitors under the chassis. But in at least 2 areas that won't be possible and the cans will have to be removed and the new capacitors installed top side.

So all I have to do now is get the courage to start. Moving the monster around to get to the capacitors is a royal PITA. But if I want longevity in the old beast it has to be done.

   

C'mon, man - if you're gonna do it, do it right!


https://pmanning.smugmug.com/Electronics/Restuffing-can-electrolytics  (Start at image 66 for the second and more successful go-round)

-Pat

With the sheer number of cans in this 535A it would take me a year to re-stuff them. 

[worsthorse]

Wandering around ebay while waiting for my soup to heat up and found a TG501 for 700USD...

eBay auction: # 124055090591

Here's my favorite part (though the bit about what a bargain it is compared to retail is a close second):

If you make offer less than BIN, I will substitute an earlier TG501 that may have issues/need repair. The only way I will send you the TG501 at a lesser offer is if you are in a foreign country trying to reduce your import tax (based on ebay sell price) but are willing to make up the difference to me in a separate payment.

The seller is also offering an SG504 for, yes, 1000USD. 

eBay auction: #124052539499

I gotta say that is some optimistic pricing. The good news is my stack of TM500 plug-ins looks to be worth close to 13000USD. Who knew? 

[bd139]

[...]

If you want to compile stuff on Windows, do it in a VM with ext4.

[...]

Not sure I understand how that would work, you can't mount an ext4 file system in Windows...   can you?

Copy build output to host machine using:

https://help.ubuntu.com/community/VirtualBox/SharedFolders

With the sheer number of cans in this 535A it would take me a year to re-stuff them. 

I never got the idea of restuffing anyway. Hey lets make new shiny pipe bombs! 

[Cubdriver]

The next project. This represents all the can electrolytic capacitors in the 535A. Looks overwhelming at first pass but I'm going to do it in stages. Intention is the simply bypass the original cans and leave them in place. And use terminal strips to mount new capacitors under the chassis. But in at least 2 areas that won't be possible and the cans will have to be removed and the new capacitors installed top side.

So all I have to do now is get the courage to start. Moving the monster around to get to the capacitors is a royal PITA. But if I want longevity in the old beast it has to be done.

   

C'mon, man - if you're gonna do it, do it right!


https://pmanning.smugmug.com/Electronics/Restuffing-can-electrolytics  (Start at image 66 for the second and more successful go-round)

-Pat

With the sheer number of cans in this 535A it would take me a year to re-stuff them. 

There can't be THAT many of them!  The one in the photo sequence was only the second I'd ever done, and took just over an hour based on the timestamps in the pics - and that was going slowly and interrupting the workflow to take the pictures.  Practice speeds things up - though a bit rusty at this point from not having done one for a while now, my last was under a half hour.

And before shotgunning them I'd take a crack at re-forming.

-Pat

[bd139]

Fucking hell this is a good one:

https://www.ebay.co.uk/itm/202898493073

“This has been used for many years, and two of the knobs have also been 'lightly chewed' by the dog!”

 

[Specmaster]

The next project. This represents all the can electrolytic capacitors in the 535A. Looks overwhelming at first pass but I'm going to do it in stages. Intention is the simply bypass the original cans and leave them in place. And use terminal strips to mount new capacitors under the chassis. But in at least 2 areas that won't be possible and the cans will have to be removed and the new capacitors installed top side.

So all I have to do now is get the courage to start. Moving the monster around to get to the capacitors is a royal PITA. But if I want longevity in the old beast it has to be done.

   

C'mon, man - if you're gonna do it, do it right!


https://pmanning.smugmug.com/Electronics/Restuffing-can-electrolytics  (Start at image 66 for the second and more successful go-round)

-Pat

With the sheer number of cans in this 535A it would take me a year to re-stuff them. 

FWIW, my view on it is screw stuffing them, take them out of circuit and replace in what ever fashion you can. My concern would be to get it recapped and working again and to hell with what it looks like. 

[WastelandTek]

another vote for no stuffing

I do like the way Paul C does it.  He uses insulated standoffs soldered to the existing cans terminals.  The top of the chassis looks original and you don't have to mount terminal strips.

I just wish I knew where to get the standoffs he uses.

[nfmax]

You can never be too thin, too rich, or have too many function generators (I just got the second freebie 33120A going) (Attachment Link)

Now you're just showing off!  How did you end up with a second freebie 33120A?

Long story - a UK R&D lab was closed down by the foreign head office/manufacturing and the contents went part to storage and part overseas. Now spinning out a new start-up which is reviving the R&D activity in more or less the original location. There was an Expedition to recover as much of the vital materials as possible, and a load of other stuff came along for the ride. A lot of dross went into the container, as well as the important stuff. Sorting out what worked and what didn't, there were 2 of these generators broken, as well as a couple that did (fortunately). The dead bodies were diverted my way....

[Mr. Scram]

I like the stuffing results but it does look like a chore and then some.

[Cerebus]

Wandering around ebay while waiting for my soup to heat up and found a TG501 for 700USD...

eBay auction: # 124055090591

Here's my favorite part (though the bit about what a bargain it is compared to retail is a close second):

If you make offer less than BIN, I will substitute an earlier TG501 that may have issues/need repair. The only way I will send you the TG501 at a lesser offer is if you are in a foreign country trying to reduce your import tax (based on ebay sell price) but are willing to make up the difference to me in a separate payment.

If you're going to indulge in conspiracy to fraudulently evade tax it's a little stupid to leave written evidence sitting around in public. However, it is very helpful to any potential customers to clearly indicate up front that you're a crook.

[med6753]

The next project. This represents all the can electrolytic capacitors in the 535A. Looks overwhelming at first pass but I'm going to do it in stages. Intention is the simply bypass the original cans and leave them in place. And use terminal strips to mount new capacitors under the chassis. But in at least 2 areas that won't be possible and the cans will have to be removed and the new capacitors installed top side.

So all I have to do now is get the courage to start. Moving the monster around to get to the capacitors is a royal PITA. But if I want longevity in the old beast it has to be done.

   

C'mon, man - if you're gonna do it, do it right!


https://pmanning.smugmug.com/Electronics/Restuffing-can-electrolytics  (Start at image 66 for the second and more successful go-round)

-Pat

With the sheer number of cans in this 535A it would take me a year to re-stuff them. 

There can't be THAT many of them!  The one in the photo sequence was only the second I'd ever done, and took just over an hour based on the timestamps in the pics - and that was going slowly and interrupting the workflow to take the pictures.  Practice speeds things up - though a bit rusty at this point from not having done one for a while now, my last was under a half hour.

And before shotgunning them I'd take a crack at re-forming.

-Pat

There's at least 11 of them in the 535A. And in order to perform a re-stuff I'd have to remove/install every one of them. I want to avoid that and only remove (permanently) ones that must be to get access.

Reform? The scope has been in good order for weeks now. Those old caps are as reformed as they will ever be. Yes, they are good but for how long? Don't want to bet on it. They are being replaced.

[med6753]

another vote for no stuffing

I do like the way Paul C does it.  He uses insulated standoffs soldered to the existing cans terminals.  The top of the chassis looks original and you don't have to mount terminal strips.

I just wish I knew where to get the standoffs he uses.

I don't know where he gets those standoffs either. But my method will achieve neat and tidy results too. The terminal strip will be bolted down on the underside with one of the can bolts. The new caps mounted to the terminal strip. Under the chassis and out of sight.

But there will be a few....especially on the Vertical Amplifier side...which will have to be mounted top side. As I dive into this I will provide pictures and it will be readily apparent why that has to be done. Stay tuned.

[med6753]

Fucking hell this is a good one:

https://www.ebay.co.uk/itm/202898493073

“This has been used for many years, and two of the knobs have also been 'lightly chewed' by the dog!”

 

"Lightly chewed" ?