Test Equipment Anonymous (TEA) group therapy thread

[bd139]

If anyone in U.K. wants some easy money hit this: https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F293432894672

Heathkit CR bridge with magic eye. Go for £100+ usually including bust ones because it has leakage test for capacitors.

I was going to grab it but honestly I can’t be arsed to deal with tube stuff now.

[tautech]

Anyone want a itsy bitsy teeny weeny scope:
https://www.trademe.co.nz/antiques-collectables/clocks-scientific-instruments/listing-2497592780.htm?rsqid=6f40f0c80f454c539056deb775be8277-001

Currently @ 10 NZD

[Specmaster]

If anyone in U.K. wants some easy money hit this: https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F293432894672

Heathkit CR bridge with magic eye. Go for £100+ usually including bust ones because it has leakage test for capacitors.

I was going to grab it but honestly I can’t be arsed to deal with tube stuff now.

To late, I've just grabbed it. Thanks bd139 

[worsthorse]

I can't speak for the newer Metcals like BD139's, but the older SP200 and MX-5 have the switch after the transformer, so the transformer primary is always live whenever the thing's plugged in.

The Tek 2901 is like that; the OCXO's oven is permanenly powered when plugged in.

So is the 184...

[bd139]

If anyone in U.K. wants some easy money hit this: https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F293432894672

Heathkit CR bridge with magic eye. Go for £100+ usually including bust ones because it has leakage test for capacitors.

I was going to grab it but honestly I can’t be arsed to deal with tube stuff now.

To late, I've just grabbed it. Thanks bd139 

   We expect pictures 

[worsthorse]

I know, I know, I said I was going to take a break from fixing/refurbing and build a couple of kits. Then I walked into the TE storage vault (aka the furnace room) and saw the stack of TM500 plugins waiting to be worked on.  I decided maybe I should take on something that I understand for a change, so I pulled out these:



Three DM502s, one with the temperature option.  Seems like every time I bought a batch of TM plugins, there was a DMM in the pile. (I also have a couple of DM502As)  Anyway, I am going to put these through a check out and burn in procedure. Naturally the one I am most interested in - the one with the temp probe option - is in the worst condition. 

They all power up and there's no obvious component damage, but their state of usability is unknown. The plan is to test them, fix the busted bits, clean them up and try to sell all but one.

[xrunner]

I know, I know, I said I was going to take a break from fixing/refurbing and build a couple of kits. Then I walked into the TE storage vault (aka the furnace room) and saw the stack of TM500 plugins waiting to be worked on.  I decided maybe I should take on something that I understand for a change, so I pulled out these:

Oh yea - I got one of those, I think everybody has at least one. 

[mnementh]

I know, I know, I said I was going to take a break from fixing/refurbing and build a couple of kits. Then I walked into the TE storage vault (aka the furnace room) and saw the stack of TM500 plugins waiting to be worked on.  I decided maybe I should take on something that I understand for a change, so I pulled out these:

(Attachment Link)

Three DM502s, one with the temperature option.  Seems like every time I bought a batch of TM plugins, there was a DMM in the pile. (I also have a couple of DM502As)  Anyway, I am going to put these through a check out and burn in procedure. Naturally the one I am most interested in - the one with the temp probe option - is in the worst condition. 

They all power up and there's no obvious component damage, but their state of usability is unknown. The plan is to test them, fix the busted bits, clean them up and try to sell all but one.

I hate to be that guy, but I suspect they'd bring more just for the knobs & binding posts. *cringe*

mnem
*Currently praying to the God of Toasters*

[bd139]

Can confirm. I made a fair bit of cash more than the scope's value out of breaking my parts mule 465 

[Specmaster]

If anyone in U.K. wants some easy money hit this: https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F293432894672

Heathkit CR bridge with magic eye. Go for £100+ usually including bust ones because it has leakage test for capacitors.

I was going to grab it but honestly I can’t be arsed to deal with tube stuff now.

To late, I've just grabbed it. Thanks bd139 

   We expect pictures 

And you'll get them, it looks to be in reasonable shape as well. I can be used with modern capacitors as well, it's not restricted valve gear.

[mnementh]

Can you actually turn the voltage down low enough on the leakage test for the low-voltage caps typically found outside a SMPS nowadays? The ranges on that function are typically very coarse... like "High Voltage" & "Higher Voltage" and that's it... LOL

In Other News...

Welp... after praying to the God Goddess of Toasters, I have emerged victorious with a functional bagel-scorching unit once more. The scene was not quite as horrific as #dragonsfuckingcars but it came close; the post-mortem revealed a long coil spring that had escaped from a slider shaft and coiled up directly under a PCB with 120VAC on it. 

Amazingly, nobody was electrocuted nor was there fire; after repairing the errant spring (and reinforcing the retainer mechanism on the slider shaft to prevent future recidivism) I was pleasantly surprised to find the timer circuit still worked!

I am now toasting up a whole loaf of pumpernickel bread to celebrate. 

mnem
I was really getting tired of sooty claws from toasting it dwagon-style... makes everything you eat afterwards taste like old cold BBQ...

[bd139]

Damn and I'd just got dragons fucking cars out of my head. Aaaand clopping came back too for some reason at the same time

[Specmaster]

Thats a real nasty vision that 

@mnem, well I do have some high voltage caps that can be tested with it, I can also become another bd139 on the low voltage ones and blow the shit out them 

I've downloaded the manual and it says I can go as low as 25V so it will do some modern day low voltages but nothing lower than 25V. But its main purpose was to clean it up, repair if required and flip it on again to fund further more modern TEA purchases 

[med6753]

Started final set up of the 535A/CA plug-in. First items to check are vertical gain and time base accuracy.


Using the FeelTech FY2200SP Function Generator as signal source. Square Wave 0.5V p-p @ 50Khz. Insurance that it's output is correct via the Siglent SDS 1052DL DSO. The Siglent has original and unmolested factory cal and also has a factory cal sheet.



Channel A of the CA plug-in. Set to 0.1V/Div and mainframe set to Time Base A sweep speed of 5us/cm. 5 major divisions deflection. Dead nuts. No adjustment required. Channel B of the CA plug-in was the same.



Next is the sweep cal. Time Base A set to 10us. It's off. A time mark generator would be best here but I don't have one so I'll have to use the square wave.



Fluke 1900A connected to the Vertical Signal Out of the 535A to make sure it hasn't drifted.



Sweep cal adjusted. Now perfect. Checked Time Base B and it's OK. Also checked various other frequencies and it tracks properly.



Follow on is to check the compensation of the CA plug-in then perform some frequency response checks. That will be a follow on post. Once that's done this project is a wrap. 

[Specmaster]

Sweep cal adjusted. Now perfect. Checked Time Base B and it's OK. Also checked various other frequencies and it tracks properly.



Follow on is to check the compensation of the CA plug-in then perform some frequency response checks. That will be a follow on post. Once that's done this project is a wrap. 

Looking at the photo, I would say that it is slightly off still, more work required to be nuts. 

[med6753]

Sweep cal adjusted. Now perfect. Checked Time Base B and it's OK. Also checked various other frequencies and it tracks properly.



Follow on is to check the compensation of the CA plug-in then perform some frequency response checks. That will be a follow on post. Once that's done this project is a wrap. 

Looking at the photo, I would say that it is slightly off still, more work required to be nuts. 

Nope, per the manual the far left and far right of the trace are NOT considered within the cal points. And you are getting some parallax errors in the photo too.     

[med6753]

Here's another view. Same 50Khz square wave with Time Base A set to 5us. Perfectly aligned.

[Specmaster]

I've always gone for the best overall fit between central 8 columns because of the possible distortion on the outer 2 columns, I've ignored those 2, and I've always been able to get them dead nuts on those 8 with relative ease.

[worsthorse]

I know, I know, I said I was going to take a break from fixing/refurbing and build a couple of kits. Then I walked into the TE storage vault (aka the furnace room) and saw the stack of TM500 plugins waiting to be worked on.  I decided maybe I should take on something that I understand for a change, so I pulled out these:

(Attachment Link)

Three DM502s, one with the temperature option.  Seems like every time I bought a batch of TM plugins, there was a DMM in the pile. (I also have a couple of DM502As)  Anyway, I am going to put these through a check out and burn in procedure. Naturally the one I am most interested in - the one with the temp probe option - is in the worst condition. 

They all power up and there's no obvious component damage, but their state of usability is unknown. The plan is to test them, fix the busted bits, clean them up and try to sell all but one.

I hate to be that guy, but I suspect they'd bring more just for the knobs & binding posts. *cringe*

mnem
*Currently praying to the God of Toasters*

Yeah, you are right but I can't be bothered breaking shit down and selling the bits one post office trip at a time.  And once I get something working (or destroy it, as I did the 184  ) unless I really want it for my bench, I don't keep stuff around for too long.

While I go through periods of binge purchasing (the save the stuff from the dumpster phase a year back comes to mind) I am really not much of a collector.  I know... heresy! 

 

[worsthorse]

Here's another view. Same 50Khz square wave with Time Base A set to 5us. Perfectly aligned.

photo goes here

Nice piece of work med!

[Specmaster]

@menm Studying the photo it looks like there is a 5V setting on the output and I have found a dedicated C-3U service manual, the U standing for the UK model and it has the following DC ranges so is pretty good for modern low voltage capacitors as well, 5V, 25V, 150V, 250V and 450V. So hopefully when it arrives it will be after replacing the selenium diode with a IN4007 and a suitable dropper resistor winner winner, chicken dinner 


Edit, found a better photo on the eBay listing and is attached

[mnementh]

Hallmark moment: Taking care of my Sick son. Pump him full of cold medicine, let him watch Austin Powers and giggle. 

mnem
*couch-tuber-time widda son*

[Specmaster]

Hallmark moment: Taking care of my Sick son. Pump him full of cold medicine, let him watch Austin Powers and giggle. 

mnem
*couch-tuber-time widda son*

Great films, which one is that you're watching?

[mnementh]

Hallmark moment: Taking care of my Sick son. Pump him full of cold medicine, let him watch Austin Powers and giggle. 

mnem
*couch-tuber-time widda son*

Great films, which one is that you're watching?

I think just the first one is more than enough brain damage for one evening. 

mnem
"How did that get in there...?"

[mnementh]

   @mnem Studying the photo it looks like there is a 5V setting on the output and I have found a dedicated C-3U service manual, the U standing for the UK model and it has the following DC ranges so is pretty good for modern low voltage capacitors as well, 5V, 25V, 150V, 250V and 450V. So hopefully when it arrives it will be after replacing the selenium diode with a IN4007 and a suitable dropper resistor winner winner, chicken dinner 

Hmmm... yeah. Since the circuit CAN go down to 5V, modding to add more useful ~16V , ~35V and ~50V ranges should be a cinch. The models I've seen all had like a 150V range & a 350-450V range. Period.

Keep us posted if you decide to go there!

mnem
"Shagadelic Baybee!!!"