Test Equipment Anonymous (TEA) group therapy thread

[cyclin_al]

Introducing my new YouTube series. How not to package stuff….

This is the HP OCXO.  Haven’t opened it yet as I’m too busy 
 

Subscribed ... 

Yay my first subscriber 

Subscribed as well.

I’m going to do some proper content at some point. Probably forward engineering and repair stuff if I get the time.

I made a TEA channel a bit ago to also "do some proper content at some point."

Oh, and the TEA channel subscribed to you, too.

OCXO box works nicely. Surprisingly the unknown uncalibrated 5381A is only 0.4Hz off and rock solid. Now I need a GPSDO to check the OXCO against  .

I’m wondering if I bother with buying that 5334B or just use this and keep the OCXO box as a transfer standard until I find someone who can check it properly. It’s probably enough for my trivial requirements like this now.

Edit: I’m being an idiot.  Of course I need the 5334B 

What about a 5334A to go with it?

Is a 5335A close enough for you?

Here is one in Canada, probably within road trip distance of 25CPS or the dwagon:
https://www.ebay.com/itm/373116324971
I cannot quite make out in the photos what is listed on the options sticker.
Tempted myself, but have already overspent on home repairs and other necessary stuff (according to SWMBO...).

Same seller on fleabay also has a HP 3311A, Fluke 1900A, crimp tools and other items.

[bitseeker]

Bargain for you guys in the US: https://www.ebay.co.uk/itm/Agilent-E3648A-DC-Power-Supply-Parts-Unit-/184995561039?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l6249&mkrid=711-127632-2357-0

Unregulated output on channel one. I’d buy it if it wasn’t $100 for shipping and customs!

Schematics and service manual http://ridl.cfd.rit.edu/products/manuals/Agilent/power%20supplies/E3646AE2.pdf

Yeah, I've been resisting. Someone please buy it! I've already got three of them depreciating in my queue. 

[bitseeker]

Is a 5335A close enough for you?

Here is one in Canada, probably within road trip distance of 25CPS or the dwagon:
https://www.ebay.com/itm/373116324971
I cannot quite make out in the photos what is listed on the options sticker.
Tempted myself, but have already overspent on home repairs and other necessary stuff (according to SWMBO...).

Same seller on fleabay also has a HP 3311A, Fluke 1900A, crimp tools and other items.

Someone (Pat maybe?) once mentioned that HP made some 3311A in metal enclosure instead of plastic. Is that readily discernible in photos? The aluminum and plastic versions of the 3478A are easy to differentiate, but I've only ever seen the plastic version of the 3311A (that I know of).

I have a 3310A, 3310B, 3312A and 33120A. A non-plasticky 3311A might be nice.

[duckduck]

Bargain for you guys in the US: https://www.ebay.co.uk/itm/Agilent-E3648A-DC-Power-Supply-Parts-Unit-/184995561039?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l6249&mkrid=711-127632-2357-0

Unregulated output on channel one. I’d buy it if it wasn’t $100 for shipping and customs!

Schematics and service manual http://ridl.cfd.rit.edu/products/manuals/Agilent/power%20supplies/E3646AE2.pdf

Thanks for lining that one up for me. 

EDIT:

While I've got a post, here's one for med:

https://portland.craigslist.org/mlt/ele/d/portland-tektronix-529-oscilloscope/7362452602.html

EDIT EDIT:

Can anyone recommend a 4-wire kelvin leads/clips set with banana (safety OK) plugs? Looking for something dirt cheap, around USD25.

[bitseeker]

Go duck, go!

[med6753]

So earlier this evening I give the Type 547 a routine power up, as I've done several times over the past few days. Basically part of my burn in and test process. Only this time I'm greeted with no trace and the smell of something getting hot. Not again!  Quickly shut it down. Yep, the +100V indicating an overload. I think this time I got it shut down before the 6080 regulator tube destroyed itself. Did a DC resistance check of the +100V bus and no short indicated.  Same sort of problem seen several times before.

My initial temptation was to get out the BFH and start swinging. This has been one frustrating restoration. After I cooled down I decided for the time being, at least a week or perhaps more, to put it aside. It's obvious I'm going to have to put the external supply back on to troubleshoot this latest fail. But there's other things I want to do like build up the 2nd scope cart. So button it back up and into the corner of bench 2. And let it mock me, I'll just ignore it.     

[mnementh]

Just like my WaveTek BNC 630 arb mocks me from under the desk... Welcome to the club, buddy. 

mnem
Here, lemme buy you a brew.

[mnementh]

Introducing my new YouTube series. How not to package stuff….

This is the HP OCXO.  Haven’t opened it yet as I’m too busy 
 

Subscribed ... 

Yay my first subscriber 

Subscribed as well.

I’m going to do some proper content at some point. Probably forward engineering and repair stuff if I get the time.

I made a TEA channel a bit ago to also "do some proper content at some point."

Oh, and the TEA channel subscribed to you, too.

OCXO box works nicely. Surprisingly the unknown uncalibrated 5381A is only 0.4Hz off and rock solid. Now I need a GPSDO to check the OXCO against  .

I’m wondering if I bother with buying that 5334B or just use this and keep the OCXO box as a transfer standard until I find someone who can check it properly. It’s probably enough for my trivial requirements like this now.

Edit: I’m being an idiot.  Of course I need the 5334B 

What about a 5334A to go with it?

Is a 5335A close enough for you?

Here is one in Canada, probably within road trip distance of 25CPS or the dwagon:
https://www.ebay.com/itm/373116324971
I cannot quite make out in the photos what is listed on the options sticker.
Tempted myself, but have already overspent on home repairs and other necessary stuff (according to SWMBO...).

Same seller on fleabay also has a HP 3311A, Fluke 1900A, crimp tools and other items.

Yeah, he's aboot a hour from me. For CAD$25 shipping, I'd prolly rather let him... tho a quick gander at just the first page showed a number of items that aggregated might make it worth the trip.

I think it's probably a good thing I'm too busy moving.

mnem
*toddles off to.... 

[mansaxel]

So having fixed the GPS receiver in my hamfest buy  Rapco 1804 GPSDO I plugged it in to power and antenna and let it run. Unfortunately it never got within 90Hz of 10MHz.

<snip>

Stuck it back in the unit and all works.

This is why this thread is the best on the entire forum. Thanks.

[BU508A]

Maybe I should have a t-shirt printed with this on it? What do you think? 

Yes! Perfect.

OK, so if we were to make some TEA-shirts, where's the place to do it? There are so many on-demand vendors, but which ones are actually good?

Yesterday I've searched for the high-res versions of the pictures used and succeeded (The Tek scope is a 535).
I tried to do some gimp stuff but this bloody program is so awfully counter-intuitive! 

I'll try again this evening and will present then here my mediocre attempts.
When I'll have a result which I think may be good enough, I'll use spreadshirt here in Germany.
Ordered several t-shirts from them and I like them.

This is an example for one of those t-shirts:

[Andrew_Debbie]

I was prepping to change out the cans that provide additional filtering to plug-in and discovered something very interesting that just might be the smoking gun that explains why the +100V has burnt up. See picture. The red resistor top on the right. See those 2 bare wires crossing? Well, they aren't touching but you can't get a sliver of paper between them. Guess the voltages? +100V and +225V.  Could it be? Who knows. Never the less I moved them apart. 

We had a similar failure on the capacitor bank for the gradient amplifiers on our old MRI scanner. 

The negative supply bus bar shorted to the chassis,  which put a spike in the ground line for the entire rack.    From the photo it looks like maybe the bar deformed from years of high power pulses until it got close enough to arc.



The capacitor bank with the lid off.    There were four of these. 



The short took out three amplifiers out of six, another capacitor bank and both power supplies.   Everything with a green tag is new.

Edit:  Each amplifier output is 675VDC  800A iMax.    500A with a 50% duty cycle.    360Arms sustained.

[bd139]

Maybe I should have a t-shirt printed with this on it? What do you think? 

Yes! Perfect.

OK, so if we were to make some TEA-shirts, where's the place to do it? There are so many on-demand vendors, but which ones are actually good?

Yesterday I've searched for the high-res versions of the pictures used and succeeded (The Tek scope is a 535).
I tried to do some gimp stuff but this bloody program is so awfully counter-intuitive! 

I'll try again this evening and will present then here my mediocre attempts.
When I'll have a result which I think may be good enough, I'll use spreadshirt here in Germany.
Ordered several t-shirts from them and I like them.

This is an example for one of those t-shirts:

The original was done in Paint.net in a meeting in a rush. Unfortunately I don’t have the original files as it was a quick one  .  If you want something printable you’ll need a much higher resolution version. I’d probably use Inkscape and look for something that traces the original sisyphus and turns it into vector image, tidy it up then stuff a 547 in there instead, then render it down to a suitable raster image.

And yes gimp is a completely awful bit of software.

I might have a bash at this today if I get a few minutes but considering it’s 8am and I’ve been working for an hour already mostly with a fire extinguisher and sticky tape it’s looking like a proper Friday the 13th 

[bd139]

So having fixed the GPS receiver in my hamfest buy  Rapco 1804 GPSDO I plugged it in to power and antenna and let it run. Unfortunately it never got within 90Hz of 10MHz.

<snip>

Stuck it back in the unit and all works.

This is why this thread is the best on the entire forum. Thanks.

This thread is the best forum in the forum 

[tonyalbus]

Arrived yesterday... just for fun, becouse they are small.

2 baby scopes.

[tautech]

Just like my WaveTek arb mocks me from under the desk... Welcome to the club, buddy. 

mnem
Here, lemme buy you a brew.

Not one of these by any chance ?
https://www.eevblog.com/forum/repair/wavetek-2025a-0-2-2-200mghz-rf-sig-gen-repair/

[BU508A]

Attached my findings here.

@med6753: can you take a good hi-res picture of your 547 in a similar style like the ones shown below?

Edit: The pictures of the scopes are taken from this site: https://w140.com/tekwiki/wiki/Main_Page

Found a better picture of the Sisyphus:

[Cubdriver]

The Fluke 8300A arrived yesterday, packaged pretty well to my pleasant surprise.  It powered up without a hitch and has been sitting connected to a resistance standard overnight.  It's within 2 ohms of the standard it's currently connected to, so I'd say the resistance functions, at least, seem to be operational.  I'll connect it to the DC calibrator later to see how it fares there, and perhaps try to get the AC one operational, too.  More photos to follow once I take a good series with the DSLR rather than the iPhone.

Glad it arrived safely! I messaged the seller about your buying it, just to see what'd happen. They said, "Wow, what a small world! Maybe your friend will give you visitation rights."

 

Is the front panel plate loose on the right side? It looked a bit like it in the listing.

Good eyes - the faceplate is a bit loose on the right side.




Won't know how it's attached until I open it up, but the rightmost two inches or so are separated from whatever is behind them, like delaminated plywood.

-Pat

[Cubdriver]

EDIT:

While I've got a post, here's one for med:

https://portland.craigslist.org/mlt/ele/d/portland-tektronix-529-oscilloscope/7362452602.html

Damn - I'd be on that in a heartbeat if it wasn't on the far side of the country!

EDIT EDIT:

Can anyone recommend a 4-wire kelvin leads/clips set with banana (safety OK) plugs? Looking for something dirt cheap, around USD25.

The Kelvin clip leads in my Fluke 8300 photos are a set of these: https://smile.amazon.com/AST-Labs-Kelvin-5-pin-meter/dp/B00M8VSM90/ref=sr_1_4?dchild=1&keywords=ast+labs+test+leads+kelvin&qid=1628841642&sr=8-4 that I bought a few years ago and put stacking banana plugs on.

Looks like they now have them with safety banana plugs already installed, too: https://smile.amazon.com/AST-Labs-Kelvin-4-channel-Banana/dp/B01H4GZP8E/ref=sr_1_3?dchild=1&keywords=ast+labs+test+leads+kelvin&qid=1628841797&sr=8-3

Not HP quality, but I've found them to be perfectly functional for my purposes.

-Pat

[Cubdriver]

Is a 5335A close enough for you?

Here is one in Canada, probably within road trip distance of 25CPS or the dwagon:
https://www.ebay.com/itm/373116324971
I cannot quite make out in the photos what is listed on the options sticker.
Tempted myself, but have already overspent on home repairs and other necessary stuff (according to SWMBO...).

Same seller on fleabay also has a HP 3311A, Fluke 1900A, crimp tools and other items.

Someone (Pat maybe?) once mentioned that HP made some 3311A in metal enclosure instead of plastic. Is that readily discernible in photos? The aluminum and plastic versions of the 3478A are easy to differentiate, but I've only ever seen the plastic version of the 3311A (that I know of).

I have a 3310A, 3310B, 3312A and 33120A. A non-plasticky 3311A might be nice.

I'm not familiar at all with the 3311A (had to look it up), so t'was not I.

I too have a 3310A & B, then my stable jumps to the 3314A (Still surprises me every time I pick it up how looooooong that thing is - you see this cute little half-rack-wide 3U faceplate on the shelf, then go to move it and realize the damned thing is 17" (~43 cm) long.  It sits next to the 8904A, which has a similar panel size, but it's 3" LONGER than the 3314A.  Deceptive little buggers!)

-Pat

[Specmaster]

So earlier this evening I give the Type 547 a routine power up, as I've done several times over the past few days. Basically part of my burn in and test process. Only this time I'm greeted with no trace and the smell of something getting hot. Not again!  Quickly shut it down. Yep, the +100V indicating an overload. I think this time I got it shut down before the 6080 regulator tube destroyed itself. Did a DC resistance check of the +100V bus and no short indicated.  Same sort of problem seen several times before.

My initial temptation was to get out the BFH and start swinging. This has been one frustrating restoration. After I cooled down I decided for the time being, at least a week or perhaps more, to put it aside. It's obvious I'm going to have to put the external supply back on to troubleshoot this latest fail. But there's other things I want to do like build up the 2nd scope cart. So button it back up and into the corner of bench 2. And let it mock me, I'll just ignore it.     

Well, not everything is bad, some good came from it, you can now discount those two bare wires coming into contact with each other as being the problem.

[VK5RC]

5381A update.

...
For the sake of people landing on this via Google one day, the new blue resistors are Royal Ohm 220R 1% 0.25W and Displays are Kingbright SA03-11EWA which are drop in replacements.

If you do futz with these, make sure you run with the lid on as there's live mains in easy accidental brushing distance of the top of the chassis.

That turned out great, bd!

I really need to buy myself a DSLR again...

Made a template for ya to save so much typing:

"I really need to buy myself a(n) _______________ again..." -- bd139

 

Thanks for the update, I feel a repair job coming up 👍

[med6753]

Attached my findings here.

@med6753: can you take a good hi-res picture of your 547 in a similar style like the ones shown below?

Edit: The pictures of the scopes are taken from this site: https://w140.com/tekwiki/wiki/Main_Page

Found a better picture of the Sisyphus:

I don't have a hi-res camera. Just this crappy Nokia 925 phone.

It really doesn't matter if the pix is a 535, 545, or 547. They all look similar.

[med6753]

So earlier this evening I give the Type 547 a routine power up, as I've done several times over the past few days. Basically part of my burn in and test process. Only this time I'm greeted with no trace and the smell of something getting hot. Not again!  Quickly shut it down. Yep, the +100V indicating an overload. I think this time I got it shut down before the 6080 regulator tube destroyed itself. Did a DC resistance check of the +100V bus and no short indicated.  Same sort of problem seen several times before.

My initial temptation was to get out the BFH and start swinging. This has been one frustrating restoration. After I cooled down I decided for the time being, at least a week or perhaps more, to put it aside. It's obvious I'm going to have to put the external supply back on to troubleshoot this latest fail. But there's other things I want to do like build up the 2nd scope cart. So button it back up and into the corner of bench 2. And let it mock me, I'll just ignore it.     

Well, not everything is bad, some good came from it, you can now discount those two bare wires coming into contact with each other as being the problem.

True, but it's a small consolation after all the hours I put into it to get it to come up, and stay up, for many hours.

[tautech]

So earlier this evening I give the Type 547 a routine power up, as I've done several times over the past few days. Basically part of my burn in and test process. Only this time I'm greeted with no trace and the smell of something getting hot. Not again!  Quickly shut it down. Yep, the +100V indicating an overload. I think this time I got it shut down before the 6080 regulator tube destroyed itself. Did a DC resistance check of the +100V bus and no short indicated.  Same sort of problem seen several times before.

My initial temptation was to get out the BFH and start swinging. This has been one frustrating restoration. After I cooled down I decided for the time being, at least a week or perhaps more, to put it aside. It's obvious I'm going to have to put the external supply back on to troubleshoot this latest fail. But there's other things I want to do like build up the 2nd scope cart. So button it back up and into the corner of bench 2. And let it mock me, I'll just ignore it.     

Well, not everything is bad, some good came from it, you can now discount those two bare wires coming into contact with each other as being the problem.

True, but it's a small consolation after all the hours I put into it to get it to come up, and stay up, for many hours.

Welcome to the world of fixing obscure faults in CRO's. 
Learnt a lot but never made much dosh doing it such was the time spent of some of them. 

Still, I well get your passion for such things as the old classic Teks. 

[BU508A]

Attached my findings here.

@med6753: can you take a good hi-res picture of your 547 in a similar style like the ones shown below?

Edit: The pictures of the scopes are taken from this site: https://w140.com/tekwiki/wiki/Main_Page

Found a better picture of the Sisyphus:

I don't have a hi-res camera. Just this crappy Nokia 925 phone.

It really doesn't matter if the pix is a 535, 545, or 547. They all look similar.

I do really like the 535 because of all those nice red knobs.