Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

...So are they worth keeping, or just ticking time bombs and my life is worth more than a few old EMI filters ??

If they're not hermetically sealed (sounds like you've opened one to see?) and you have use for them, just replace the caps as you need them. The big problem with fixing the Schaffner filters is not the failure mode... it's the amount of utter assache involved in getting them apart, and almost impossible to do without destroying the thing.

I rebuilt oodles of similar-looking filters back in the day with the old Wollensak cassette players they used in the AV dept; they were Euro-production models, and when they got older would cause 60-cycle hum in recordings when running on US mains. New safety caps sorted them 100%.

mnem
 

[mnementh]

If this is as described (ie: used - previously owned but fully operational) and anyone is near to Chippenham (collection only) this is a bargain:  https://www.ebay.co.uk/itm/175177658083

Blasted enablers; I hate you all. I'm picking it up tomorrow, after testing.

Anybody want a Tek 2467? https://www.ebay.co.uk/itm/165357463536   

*wibble*   

Does not ship to US.   

Send him a message mentioning GSP? Check he knows how to pack a scope

I fucking hate you.     Very cordially, of course.

mnem

[mnementh]

Retaliatory Strike:       eBay auction: #384738419199

mnem
};=)~~~~<

[Vince]

Next advice please.

Still from the same old friend... got these 4 EMI line filters. 5 amps, 40 years old according to date codes (ranging from 1981 to 1983).
50x50mm by 28mm thick/high.

Can old filters be trusted, I mean the caps in them, or should I play it safe and throw them away ?

Sticker gives no internal schematic but assuming the usual layout, I tested them blind, and it seems for now at least, that they have not failed... but might explode I guess first time I power them up... so is it worth it...

Inductance betweden input/output is about 100uH.

Y caps measure about 7nF, and X cap about 3nF.

According to the markings, they are made by ' SAE '.

Looked them up, still in business today. They claim to be making top notch filters for industrial use, medical blah blah blah, since the early '70s.

https://www.saepower.com/emirfi-filter-products/

Might just be marketing BS, it's free to talk.
I am sure if I go to RIFA's website they will claim the same thing as SAE...


So are they worth keeping, or just ticking time bombs and my life is worth more than a few old EMI filters ??

You could power them up on the mains using a suicide cord. Experience says that if they are going to go it is within the first 15 minutes of having power applied. Needless to say, do this outside, unless you like the gentle scent of Eau de Rifa attached to all your clothing and soft furnishings for months to come.

Too late, I have already experience that fragrance the other day, remember, when my Tek 2467B released the magic smoke ! Lots of it indeed, and quite smelly... which says a lot coming from me because I am kinda " smell disabled " and can't smell anything usually, not even melting plastic which people can small instantly even from 10 meters away. But me, with my nose on it, I can't smell a thing.
So yeah I am sure this RIFA smell must be very strong for normal people...

[Vince]

...So are they worth keeping, or just ticking time bombs and my life is worth more than a few old EMI filters ??

If they're not hermetically sealed (sounds like you've opened one to see?) and you have use for them, just replace the caps as you need them. The big problem with fixing the Schaffner filters is not the failure mode... it's the amount of utter assache involved in getting them apart, and almost impossible to do without destroying the thing.

I rebuilt oodles of similar filters back in the day with the old Wollensak cassette players they used in the AV dept; they were Euro-production models, and when they got older would cause 60-cycle hum in recordings when running on US mains. New safety caps sorted them 100%.

mnem
 

Rebuilding an EMI filter ?! Never thought of that ! That's why I keep posting here, people always surprise me...

No I have not opened any of them, not sure why you think that ?

The one that looks a little different than the others is because although it's exactly the same part number, it's a little older (1981 vs 1983). The info on it is printed on a white and blue label, whereas the others have the same info printed in black directly onto their metal bodies, no label.

They look sealed.. yet might be possible to open them up anyway. It looks like they are held shut with a bead of solder all around. Gave it a try but my modest 50 Watt Magnastat soldering iron is not up to the task... maybe once I can afford a 130W PS900 Metcal unit with a large/chunky tip, I could stand a chance...

[tggzzz]

Send him a message mentioning GSP? Check he knows how to pack a scope

I fucking hate you.     Very cordially, of course.

(And fortunately I don't want a Wheatstone bridge to complement my KVDs. Better luck next time )

[Vince]

...However from the top of his head he did remember that yes it was indeed a 24V nominal supply voltage, and that accuracy was 10-9.
... which is splendid for my personal use... means it is one order of magnitude more accurate than my 8 digit Nixie counters ! So I could use this oscillator to feed all my Nixie counters... I have two of them with 5 digits, and two of them with 8 digits. And since it is the same Vintage as these counters, it's 1MHz, which is what these old counters take. They don't take 10MHz. So it's plug and play ! 

So there you go, my first step in time nuttery, I have my first Freq ref !!! 

My friend said he can't remember what the output impedance is, and that I should measure it.

Hmmm.... could be one last fun experiment to do before I put it away and resume sorting components ! Stay tuned !!

Of course, you cannot put it away until you've built it into a enclosure [..]

Actually I am indeed considering make a little enclosure for it as you suggest ! 
However any construction work has to be postponed until the garage is built, in a couple years all going well.
The living room is too much of a cluster fuck to do any work.
Unless you are thinking of an enclosure hastily put together in 10 minutes using cardboard boxes left overs, using scotch tape and a sharpie to draw the front panel " art work "....
...but I have more ambition than this, I want something decent, maybe even nice dare I say.

with a distribution amplifier and a nice low-noise linear power supply...

...Built using one of those transformers you couldn't decide  to do with.   

mnem

Hmmm... touché ! 

I didn't see that coming, but yes that would be a nice litle design and build exercise, and an excuse to mess around with these transformers and justify keeping them around... while keep the enclosure budget tight. Hmm I like the idea 

OCXO takes only 5 Watts top, when cold, dropping to half that once warm, so any of my tiny crappy transformers should be good enough. Just need to find one with high enough a voltage. 24Vdc, add 3 volts for a standard 7824 or 3 pin adjustable regulator, that's 27Vdc. So I need to find a transformer with at least 19 Volts RMS, sustained under 210mA load.

[mnementh]

Rebuilding an EMI filter ?! Never thought of that ! That's why I keep posting here, people always surprise me... No I have not opened any of them, not sure why you think that ?

The one that looks a little different than the others is because although it's exactly the same part number, it's a little older (1981 vs 1983). The info on it is printed on a white and blue label, whereas the others have the same info printed in black directly onto their metal bodies, no label.

They look sealed.. yet might be possible to open them up anyway. It looks like they are held shut with a bead of solder all around. Gave it a try but my modest 50 Watt Magnastat soldering iron is not up to the task... maybe once I can afford a 130W PS900 Metcal unit with a large/chunky tip, I could stand a chance...

Oh, sorry, I misunderstood. So what you meant was you were measuring the entire capacitance of the circuit, not the individual caps.   

 No, the ones I rebuilt were "sealed" with two ~5mm spots of solder; took but a trice to pop them open with the 150W GT7. Also used conventional ceramic disc and epoxy-encased polyester caps, not RIFAs. The service was done per a TSB from the MFR.

If the ones you have are hermetically sealed as you describe, def more assache than they're worth. I'd chunk 'em. They're livestock well beyond their best-by date.

mnem

[mnementh]

...Of course, you cannot put it away until you've built it into a enclosure [..]

Actually I am indeed considering make a little enclosure for it as you suggest ! 
However any construction work has to be postponed until the garage is built, in a couple years all going well.
The living room is too much of a cluster fuck to do any work.
Unless you are thinking of an enclosure hastily put together in 10 minutes using cardboard boxes left overs, using scotch tape and a sharpie to draw the front panel " art work "....
...but I have more ambition than this, I want something decent, maybe even nice dare I say.

with a distribution amplifier and a nice low-noise linear power supply...

...Built using one of those transformers you couldn't decide  to do with.   

mnem

Hmmm... touché ! 

I didn't see that coming, but yes that would be a nice litle design and build exercise, and an excuse to mess around with these transformers and justify keeping them around... while keep the enclosure budget tight. Hmm I like the idea 

OCXO takes only 5 Watts top, when cold, dropping to half that once warm, so any of my tiny crappy transformers should be good enough. Just need to find one with high enough a voltage. 24Vdc, add 3 volts for a standard 7824 or 3 pin adjustable regulator, that's 27Vdc. So I need to find a transformer with at least 19 Volts RMS, sustained under 210mA load.

Yeah, but now you see how scope creep invades everything. As soon as you start thinking about using this as a lab reference, you need a distribution amp. 

This means a big enough enclosure for multiple BNC jacks, and now your PSU design needs to allow for powering that as well, even if you do take the lazy route and repurpose a ready-made CATV or Video Distribution amplifier module for the purpose... if you do decide to design the amp yourself, now you're jumping from one rabbit-hole into a new one with whatever CAD software suite you decide to go with... and before you know it, you're totally    .

mnem
Exactly how this happened:   

[mnementh]

LOOK! Over There! A DIVERSION!!!    https://jwst.nasa.gov/content/webbLaunch/whereIsWebb.html

mnem
 

[Vince]

Rebuilding an EMI filter ?! Never thought of that ! That's why I keep posting here, people always surprise me... No I have not opened any of them, not sure why you think that ?

The one that looks a little different than the others is because although it's exactly the same part number, it's a little older (1981 vs 1983). The info on it is printed on a white and blue label, whereas the others have the same info printed in black directly onto their metal bodies, no label.

They look sealed.. yet might be possible to open them up anyway. It looks like they are held shut with a bead of solder all around. Gave it a try but my modest 50 Watt Magnastat soldering iron is not up to the task... maybe once I can afford a 130W PS900 Metcal unit with a large/chunky tip, I could stand a chance...

Oh, sorry, I misunderstood. So what you meant was you were measuring the entire capacitance of the circuit, not the individual caps.   

mnem

Yes, as I said I tested them "blind", ASSUMING what the internal construction/schematic could likely be. So I assumed the simplest, so a singe X cap, only two Y caps, and two inductors. Once I assumed that, then measuring everything from the outside terminals should lead valid results...

But enough guess work... I have it all figured out now : might not have a big enough soldering iron, but what I do have is a little vice and a hacksaw ! Works too ! 

So I opened one up... as you can see it's lined in thin cardboard all over, filled with black stuff which is very hard and brittle stuff, had a go at it, only destruction can follow, so absolutely not "serviceable", so no regrets here. One can see it has 4 inductors not just two, so the "one" must have been split in to, hence there must be some intermediary Y caps halfway the signal path, so my previous blind cap measurements must have been off.

So I guess to conclude, the most reasonable thing to do is to throw all of these filters away...

[Vince]

LOOK! Over There! A DIVERSION!!!    https://jwst.nasa.gov/content/webbLaunch/whereIsWebb.html

mnem
 

That's one hell of a TE , expensive one !! 

[mnementh]

   LOOK! Over There! A DIVERSION!!!    https://jwst.nasa.gov/content/webbLaunch/whereIsWebb.html

mnem
 

That's one hell of a TE , expensive one !! 

All built standing on the shoulders of nerds like us, and the very tools we still love and collect. 

mnem
     https://mars.nasa.gov/mars2020/

[Robert763]

If this is as described (ie: used - previously owned but fully operational) and anyone is near to Chippenham (collection only) this is a bargain:  https://www.ebay.co.uk/itm/175177658083

Blasted enablers; I hate you all. I'm picking it up tomorrow, after testing.

Anybody want a Tek 2467? https://www.ebay.co.uk/itm/165357463536   

*wibble*   

Does not ship to US.   

Send him a message mentioning GSP? Check he knows how to pack a scope

I fucking hate you.     Very cordially, of course.

mnem

I can forward it for you  Mind you as it has  MCP it may need an export licence.
I was tempted myself for a second. I have night vison and X-ray MCP imagers but no MCP CRTs.....

[Vince]

...Of course, you cannot put it away until you've built it into a enclosure [..]

Actually I am indeed considering make a little enclosure for it as you suggest ! 
However any construction work has to be postponed until the garage is built, in a couple years all going well.
The living room is too much of a cluster fuck to do any work.
Unless you are thinking of an enclosure hastily put together in 10 minutes using cardboard boxes left overs, using scotch tape and a sharpie to draw the front panel " art work "....
...but I have more ambition than this, I want something decent, maybe even nice dare I say.

with a distribution amplifier and a nice low-noise linear power supply...

...Built using one of those transformers you couldn't decide  to do with.   

mnem

Hmmm... touché ! 

I didn't see that coming, but yes that would be a nice litle design and build exercise, and an excuse to mess around with these transformers and justify keeping them around... while keep the enclosure budget tight. Hmm I like the idea 

OCXO takes only 5 Watts top, when cold, dropping to half that once warm, so any of my tiny crappy transformers should be good enough. Just need to find one with high enough a voltage. 24Vdc, add 3 volts for a standard 7824 or 3 pin adjustable regulator, that's 27Vdc. So I need to find a transformer with at least 19 Volts RMS, sustained under 210mA load.

Yeah, but now you see how scope creep invades everything. As soon as you start thinking about using this as a lab reference, you need a distribution amp. 

This means a big enough enclosure for multiple BNC jacks, and now your PSU design needs to allow for powering that as well, even if you do take the lazy route and repurpose a ready-made CATV or Video Distribution amplifier module for the purpose... if you do decide to design the amp yourself, now you're jumping from one rabbit-hole into a new one with whatever CAD software suite you decide to go with... and before you know it, you're totally    .

mnem

Oh I didn't think of the amplifier bit, uh.......... erm.... OK OK.... youplaboom... 

I certainly don't want a huge box and a big fan... and I am no RF expert.
I don't know, I will see what I can do ?! 

However I would think I would not need any fancy amplifier chip/ circuitry ?!

The output impedance of the oscillator is only 220 ohms and from the top of my head, the input impedance of my old counters, is much higher than that, so no need to amplify...
What I am more concerned about, is that each counter probably has different requirements about voltage levels and waveform (sine or square).
So the very first thing I would do, it dig out the old printed manual that I am lucky enough to have for every one of them, and compile all their requirements so I have an overview of what counter needs what, or can live with.

Then try to see if I can find a waveform and voltage level that can be compatible with all of them. If not, then make a few output stages/drivers that can be configured at will to produce whatever voltage levell of wave form that a particular counter wants.

Since the input impedance of the counters is not stupid low (not 50R I think), and it's only 1MHz we are talking about, which is at the reach of jelly bean logic chip I would think... then II could use just that.
Don't need any (voltage) amplification I would think since the OCXO puts out nearly 5Volts (4.85V or so). Don't need current amplification either for reasons explained above so... really I don't think it should be too difficult to come up with something that works ?! 

Maybe I am being naive due to total lack of experience and knowledge in this domain... but I am willing to at least give it a try. Will be educational and a fun design exercise. So nothing to lose really, only fun and experience to be gained... it's all positive.

Yeah ! I quite like this little project ! I think it will be high on my list of projects once the lab is operational !!! 

[mnementh]

I fucking hate you.     Very cordially, of course.

mnem

I can forward it for you  Mind you as it has  MCP it may need an export licence.   I was tempted myself for a second. I have night vision and X-ray MCP imagers but no MCP CRTs.....

MCP CRTs are STILL a controlled technology...? I mean... the original design goes back what... 70-something years? 

And I know I'm gonna regret it... but please let me know how painful it would be.

mnem
 

[med6753]

Success! With my bodged up jig and lots of Pennzoil Z-Q penetrating oil the galling or whatever has broken free and the shaft is turning independently of the outer ring. It still needs to be worked a while but with each rotation it's getting smoother and easier. I'm going to keep slowly working it today and then tomorrow degrease it and lube it some Lithium grease.

Whew! 

Edit.....and the detent is working perfectly.

 

[Cerebus]

LOOK! Over There! A DIVERSION!!!    https://jwst.nasa.gov/content/webbLaunch/whereIsWebb.htmll?units=metric

mnem
 

TFTFY

[mnementh]

Success! With my bodged up jig and lots of Pennzoil Z-Q penetrating oil the galling or whatever has broken free and the shaft is turning independently of the outer ring. It still needs to be worked a while but with each rotation it's getting smoother and easier. I'm going to keep slowly working it today and then tomorrow degrease it and lube it some Lithium grease.

Whew! 

Edit.....and the detent is working perfectly.   

   

Well done, Papa Smurf!!!

mnem
Never quit.   

[tautech]

Success! With my bodged up jig and lots of Pennzoil Z-Q penetrating oil the galling or whatever has broken free and the shaft is turning independently of the outer ring. It still needs to be worked a while but with each rotation it's getting smoother and easier. I'm going to keep slowly working it today and then tomorrow degrease it and lube it some Lithium grease.

Whew! 

Edit.....and the detent is working perfectly.

Well done Med ! 
Live by this motto: Patience and persistence can stretch a blowfly's arse hole over a bucket ! 

Sometimes the trouble is well worth the effort. 

[Peter_O]

...
Exactly how this happened:   

What can you use a server psu for if not printing something for it? 

[factory]

If this is as described (ie: used - previously owned but fully operational) and anyone is near to Chippenham (collection only) this is a bargain:  https://www.ebay.co.uk/itm/175177658083

Blasted enablers; I hate you all. I'm picking it up tomorrow, after testing.

Anybody want a Tek 2467? https://www.ebay.co.uk/itm/165357463536   

*wibble*   

Does not ship to US.   

Send him her a message mentioning GSP? Check he she knows how to pack a scope

The 214A was packed with foam padding & polystyrene in a fairly large CPC box, it arrived intact, but it doesn't do any harm asking about packing for international shipping.
I did have to contact the seller, as she forgot to send the PH163 power lead, this arrived with another purchase on Saturday. 
 
David

[worsthorse]

* worsthorse wanders in, looks around, and is happy to see that not much has changed... 

[m k]

All my old transformers, SLA bateries and even stripped chassis go to the metal re-cyclers. Last boot load raised £80 and I picked up a Time 1010 Voltage calibrator for £2 while I was there 

Dang,
different world again.
Here it's "be happy you don't need to pay" style.

BTW,
I once lost a tester and thought that no way I'm every now and then spending a grand just because I can't manage my stuff.
So I bought something cheaper and later found the first one, still there with spending.
Maybe one day I even find that minitester with only few leds, it's not really lost, just out of site.

[Specmaster]

Holy shit balls, just had an email from our energy supplier where we get our electric and gas from, and from 1st April, our bill is almost doubling to almost £300 a month, put that together with the increase in rent, rates, phone, internet, diesel for the car, all of which are also seeing massive increases, I have to decide between eating and TEA 

It looks as if I'm going to start flipping a few things in order to keep my head above the water line here, thanks to Brexit, Covid and silly boy Putin, geez what a rough ride this is going to be for a while.