Test Equipment Anonymous (TEA) group therapy thread

[tggzzz]

There's a Tek 1502 Time Domain Reflectometer[1] up for grabs on fleabay. Unusually, it looks like both it and its printer work. Mind you, the printer will only work until that roll of paper is exhausted, since the thermal paper with sprocket holes is unobtanium.

https://www.ebay.co.uk/itm/Tektronix-1502-Time-Domain-Reflectometer-with-working-printer/283855816390

No affiliation with the seller.

[1] one of my fetishes; I can't resist the twinkling display of a very portable 4GHz analogue sampling scope which allows you to see cable/connector/PCB discontinuities with a resolution of a couple of cm. I don't recommend storing them under water, unless you have recently verified all the seals are fully intact

[mnementh]

So do I allocate $ to non critical cool TEA or buy more Laser bits this week? Curse my current non budget

What could more cool than lasers..? 

Nixies and lots of knobs 

More worrying is Rocky Horror showing on the local idiot free to air tonight - will it cause Nightmares of Dragons in Fishnets 

I vote for LASER Sharks. Riding T-Rexes. With Ninjas. Doing Rocket Surgery.

mnem

[mnementh]

...Did either of you bother to even look at the article...?   

mnem
 

Nope, but they might have spotted the authors name...Dominic Cummins, the mastermind behind everything thats bad in British politics right now 

    I was talking about MY article, ya drillbit.         https://www.eevblog.com/forum/chat/3d-printer-yet/msg3032618/#msg3032618

mnem
I am Diogenes.

[mnementh]

Odin, far og klokeste av alle guder, gi meg veiledning, visdom og seier i mine anstrengelser

now I hope that I got that right, my norse is somewhat rusty.

Nei! Frøken, det er ikke lov å kjøre på motorveien med disse kattene! Er de til og med forsikret? Papirene takk!

  I always insure my road cats; for just such a contingency.

I thought I'd go through all the capacitors from the 4503 that I recapped and it was just as I suspected at the start when I wasn't convinced that doing a full recap is not always necessary, but most of us here do it any way, not a single capacitor actually warranted being replaced, all had very good ESR and capacity wise, were well within the spec by a good margin, so that was my first full recap and may well be my last without testing some of the caps at random. 

You and I both know the reasoning is not about "Are they good now?" but rather "Can I trust them to stay good for the next decade while this piece of gear is on my bench, and am I willing to put up with the brainfuck that ensues if not...?"

mnem
 

[Cerebus]

I've just made a great, stable 34MHz oscillator out of two 2N3904s and two 2N3906s. Yup, you guessed it - amplifiers oscillate and oscillators don't.  Rock solid though... 

Now, where's that pack of ferrite beads?

[mnementh]

Nutters!

Anyway, in-context, I doubt bean wants sharks in his house to mount his laser/s on, and do we really want powerful coherent gamma ray sources anywhere near us?
I mean, given that gamma ray bursts from quasars can sterilise an entire galaxy, and all, ijs   

https://youtu.be/3ANufwUPFm8

Well, DUH!!! That's why you put the sharks on T-Rexes, so he can turn them loose to roam the Outback at will. Takes up muck less shed space that way.

See an original 1973 Rocky Horror Picture Show T-shirt in the picture below. I can still get in it, but the fabric is becoming fragile.

Is that the fabric of the T-shirt, or the fabric of the body contorting to get into a T-shirt when it's more used nowadays to a small-check shirt and a comfy cardigan?   

Both the fabric and the material are more fragile now But the material is the limiting factor in this case (If you look carefully, you can see a split seam in the left armpit)

Keep The Faith, buddy.    Pass it on to the next generation.

mnem
*tinker-ily*

[Cerebus]

There's a Tek 1502 Time Domain Reflectometer[1] up for grabs on fleabay. Unusually, it looks like both it and its printer work. Mind you, the printer will only work until that roll of paper is exhausted, since the thermal paper with sprocket holes is unobtanium.

https://www.ebay.co.uk/itm/Tektronix-1502-Time-Domain-Reflectometer-with-working-printer/283855816390

No affiliation with the seller.

[1] one of my fetishes; I can't resist the twinkling display of a very portable 4GHz analogue sampling scope which allows you to see cable/connector/PCB discontinuities with a resolution of a couple of cm. I don't recommend storing them under water, unless you have recently verified all the seals are fully intact

Could have done with one of these an hour ago. I was just making up some BNC <=> RG316 cables with "not quite the right crimp tool", destined to be tested and then cut in half to make Z₀ probes. They look fine with a signal on them, but a TDR would have just given that extra bit of confidence that "the job's a good un".

[mnementh]

There's a Tek 1502 Time Domain Reflectometer[1] up for grabs on fleabay. Unusually, it looks like both it and its printer work. Mind you, the printer will only work until that roll of paper is exhausted, since the thermal paper with sprocket holes is unobtanium.

https://www.ebay.co.uk/itm/Tektronix-1502-Time-Domain-Reflectometer-with-working-printer/283855816390

No affiliation with the seller.

[1] one of my fetishes; I can't resist the twinkling display of a very portable 4GHz analogue sampling scope which allows you to see cable/connector/PCB discontinuities with a resolution of a couple of cm. I don't recommend storing them under water, unless you have recently verified all the seals are fully intact

I'd totally buy that, if it weren't halfway round the fucking planet and cost me a prince's ransom to get it here. 

mnem
*shameless TEA hussy*

[Specmaster]

I thought I'd go through all the capacitors from the 4503 that I recapped and it was just as I suspected at the start when I wasn't convinced that doing a full recap is not always necessary, but most of us here do it any way, not a single capacitor actually warranted being replaced, all had very good ESR and capacity wise, were well within the spec by a good margin, so that was my first full recap and may well be my last without testing some of the caps at random. 

You and I both know the reasoning is not about "Are they good now?" but rather "Can I trust them to stay good for the next decade while this piece of gear is on my bench, and am I willing to put up with the brainfuck that ensues if not...?"

mnem
 

Well sort of yes and no, there no real way of telling how old the caps are before you buy them. I mean, now and then you see a sale on some caps, now is that because they just over ordered and want to reduce stock holding, or is it that they might be years old anyway? Selling them cheap is fair enough, BUT there is a point in time when those caps would have been sold at their normal price, you might buy those, install them and then before you know it, you have the brainfuck that ensues anyway.....Just saying.....

[mansaxel]

  LOL IRL... That doesn't sound right; many of my friends on other boards have defended the EU Fiesta/Escort as having price/reliability comparable to Toyota Corolla/Camry. In other words, a cheap car that's good for 10 years even if you abuse it and longer if you take care of it. But thanks for the belly laugh; I needed it.

I'd argue that once Japan got their corrosion problems under control, they proceeded to make some of the most reliable cars in existence. Which Ford never, ever, have managed, starting with the Taunus and Granada, where the order of the day is fill up on engine oil and check the fuel   

Granted, the Japanese cars are boring and dull, but reliably so. OTOH, any Chevrolet, which is what Alamo gives you when you rent "mid-range", (my main source of info on US cars) has inherited the "boring and dull" part hook, line and sinker, but sort of missed out on the "reliable", so boring is sortakinda universal unless you pay silly money. Character, in positive terms can be had, if you look around. I like to think of my Volvo having some of it, even if it was conceived during the "Ford owns Volvo Cars" epoch (it's a 2001 V70) and it of course is subtle in "character" compared to, say, anything with a Lucas electrical system. But, they didn't fail on the "reliable". 365000 km and counting.

I would make it a mission to swap the controls around on the offending half of that thing fer damn sherr.

Now, I haven't opened the Uni-T, because since I got a working one (the first one, a christmas gift from Enabler, Mark 1, Mod 3 (the Wife) was a DOA), it's been very reliable. Within 15%.   

If those pots are chassis mount and cable-to-pcb, I might follow your idea. Or, I might not be arsed. Time will tell.

[0culus]

didn't bother me a bit. (Attachment Link)

Yes...yessssss...he's being slowly assimilated. 

So now that I have things on the distribution amp getting their frequency references from GPS, here's the 8664A feeding a CW into the 53310A. This capture has been running overnight, and the mean of the frequency distribution is only 16.8 microhertz off what the 53310A says is 433 MHz exactly. I'd say that's plenty of digits for me. 

Here's how to set up the 53310A for precision measurements like this:




Histogram: Fast Hist, accumulation on, 10 measurements
Sampling: Manual, 500 ms
Vertical: Span, 0.01 Hz or 10 mHz. Can go down to 5 mHz if you want.

[mnementh]

Unfortunately that bleeding edge sillycon was EXTREMELY sensitive to overheating unless you took precautions or else you would wind up with a hybrid chunk of sand.   

Not really THAT sensitive; just high-performance ICs that REQUIRE active cooling, and it was designed to provide that WITH THE CASE ON set on a bench. It was designed by engineers who knew a lot more about what they were doing than the average shaved simian who bought their product used 3rd-hand expecting it to be as forgiving as their hollow-state stuff. 

You wouldn't fault a modern high-current cumputing device for horking up its chips when the fan dies; why so unforgiving of a 30-year-old Tek product? It's not THEIR fault you used it in a confined space without finding, reading and heeding all the documentation that told you in bright red letters not to operate it without adequate ventilation. 

You just got caught by the sharp edge of the Tek learning curve is all.

mnem
Why am I still here...?

Holy shit....are you done beating me with the silly stick?? 

<whack!>  Thank you sir, may I have another?

<whack!>  Thank you sir, may I have another?

<whack!>  Thank you sir, may I have another?

 

-Pat

mnem
$32 for a fucking stick...? meh... I've made worse investments.

[med6753]

I thought I'd go through all the capacitors from the 4503 that I recapped and it was just as I suspected at the start when I wasn't convinced that doing a full recap is not always necessary, but most of us here do it any way, not a single capacitor actually warranted being replaced, all had very good ESR and capacity wise, were well within the spec by a good margin, so that was my first full recap and may well be my last without testing some of the caps at random. 

You and I both know the reasoning is not about "Are they good now?" but rather "Can I trust them to stay good for the next decade while this piece of gear is on my bench, and am I willing to put up with the brainfuck that ensues if not...?"

mnem
 

Well sort of yes and no, there no real way of telling how old the caps are before you buy them. I mean, now and then you see a sale on some caps, now is that because they just over ordered and want to reduce stock holding, or is it that they might be years old anyway? Selling them cheap is fair enough, BUT there is a point in time when those caps would have been sold at their normal price, you might buy those, install them and then before you know it, you have the brainfuck that ensues anyway.....Just saying.....

You may find this incredible but I agree with mnem. Anything approaching 30+ years old is suspect. I don't care if it tests good. Tomorrow it could start leaking. It's the old saying "pay me now or pay me later". I'd rather minimize the risk by changing them out.

And yes, some capacitor stock COULD be old. MAYBE 10 years. But guaranteed it hasn't been sitting around for 30 years if it's a legitimate source and not someone's stock sitting in a garage. 

[tggzzz]

There's a Tek 1502 Time Domain Reflectometer[1] up for grabs on fleabay. Unusually, it looks like both it and its printer work. Mind you, the printer will only work until that roll of paper is exhausted, since the thermal paper with sprocket holes is unobtanium.

https://www.ebay.co.uk/itm/Tektronix-1502-Time-Domain-Reflectometer-with-working-printer/283855816390

No affiliation with the seller.

[1] one of my fetishes; I can't resist the twinkling display of a very portable 4GHz analogue sampling scope which allows you to see cable/connector/PCB discontinuities with a resolution of a couple of cm. I don't recommend storing them under water, unless you have recently verified all the seals are fully intact

Could have done with one of these an hour ago. I was just making up some BNC <=> RG316 cables with "not quite the right crimp tool", destined to be tested and then cut in half to make Z₀ probes. They look fine with a signal on them, but a TDR would have just given that extra bit of confidence that "the job's a good un".

... or a bad 'un!

I have reason to believe that you could get £200 for one, so the current price (£40) is jammy git territory

Mnementh might like to ask the vendor whether they would ship to Canada.

[BU508A]

Here is a quick update to my broken USB charger in the Brennenstuhl plug board.
Reference: https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg3008604/#msg3008604

Today, the spare parts arrived from China, the MOSFET SVF4N65MJ and the controller IC IW1691-03.
I replaced the IC first, because the MOSFET didn't show any signs of malfunction. 
And this is the result:



I'd say: winner winner, chicken dinner! 

[Neomys Sapiens]

of course it's nutty. Do we want the source of a GRB anywhere near us ? near meaning less than 500 Mill. light years ?
don't think so ...
it's a matter of fact that scientists are working on gamma ray lasers, though, it's one thing that's needed for chip manufacturing to get past the 7 nm down to even smaller structures...
anyway.

For that too, yes. And some other fleeting goals.

[med6753]

I had to rebuild my 190VDC reference. For some reason the original LR8N3-G regulator decided to give up the ghost. I might have accidentally shorted it. Anyway, new regulator and it's back up.

It's not the greatest reference in that the regulator is spec'ed to 5% so it does bounce around. But it's suitable for spot checks.

[mnementh]

Jeezus H Christ a-hoppin' on a pogo stick... there's been a Civil Defense or whatever siren going off outside for the last 40 minutes, and nowhere can I find any information on what it's for, or even what the local EBS frequencies are.

Nothing on TV, all web searches for emergency broadcast take me to some moronic gov.ca website where I can sign up for EMS messages in case of emergencies.  Of course, nobody thought to include a live feed of any CURRENT emergency notifications on the site. 

Called the local police non-emergency line, they acted like I was crazy for wanting to know what the air raid sirens were for. Nothing on the local Weather frequencies. Interesting to know that we are about 60 kliks north of two nuclear power plants tho...

Guess the "State of Unpreparedness" isn't just a US thing; even tho they do seem to exemplify it.

mnem
 

[tggzzz]

I thought I'd go through all the capacitors from the 4503 that I recapped and it was just as I suspected at the start when I wasn't convinced that doing a full recap is not always necessary, but most of us here do it any way, not a single capacitor actually warranted being replaced, all had very good ESR and capacity wise, were well within the spec by a good margin, so that was my first full recap and may well be my last without testing some of the caps at random. 

Yebbut there's always the chance of damaging the board.

I currently ought to replace these, to remove spurs that are -70dBc down:




And I have to replace those Rifas for the obvious reason:



Fear is giving me the opportunity to improve my techniques and tools

[Neomys Sapiens]

Y'all just don't know any better. You paid for a Chevy Nova and got a Yugo; how wouldja know any better when all you've ever driven is a Opel?

Do you know, by the way, that Ford car manufacture in Europe exists solely to make Opel the second worst car being made?

Basically correct. Although, when I think 'yuck! - Opel' I have to remind myself that I drove one once. Got an Vectra 4x4 as a gapfiller and got so used to it that I kept it for over a year.

[med6753]

I thought I'd go through all the capacitors from the 4503 that I recapped and it was just as I suspected at the start when I wasn't convinced that doing a full recap is not always necessary, but most of us here do it any way, not a single capacitor actually warranted being replaced, all had very good ESR and capacity wise, were well within the spec by a good margin, so that was my first full recap and may well be my last without testing some of the caps at random. 

Yebbut there's always the chance of damaging the board.

I currently ought to replace these, to remove spurs that are -70dBc down:


And I have to replace those Rifas for the obvious reason:



Fear is giving me the opportunity to improve my techniques and tools

It looks like just a routine cap change to me. I would get rid of all of them, including that little yellow tant. Considering the total cost of the capacitors and the time/labor avoided later in troubleshooting it's cheap and a no brainer.

[BU508A]

I had to rebuild my 190VDC reference. For some reason the original LR8N3-G regulator decided to give up the ghost. I might have accidentally shorted it. Anyway, new regulator and it's back up.

It's not the greatest reference in that the regulator is spec'ed to 5% so it does bounce around. But it's suitable for spot checks.

You DO love your 8505A, don't you?     

[mnementh]

I thought I'd go through all the capacitors from the 4503 that I recapped and it was just as I suspected at the start when I wasn't convinced that doing a full recap is not always necessary, but most of us here do it any way, not a single capacitor actually warranted being replaced, all had very good ESR and capacity wise, were well within the spec by a good margin, so that was my first full recap and may well be my last without testing some of the caps at random. 

You and I both know the reasoning is not about "Are they good now?" but rather "Can I trust them to stay good for the next decade while this piece of gear is on my bench, and am I willing to put up with the brainfuck that ensues if not...?"

mnem
 

Well sort of yes and no, there no real way of telling how old the caps are before you buy them. I mean, now and then you see a sale on some caps, now is that because they just over ordered and want to reduce stock holding, or is it that they might be years old anyway? Selling them cheap is fair enough, BUT there is a point in time when those caps would have been sold at their normal price, you might buy those, install them and then before you know it, you have the brainfuck that ensues anyway.....Just saying.....

You may find this incredible but I agree with mnem. Anything approaching 30+ years old is suspect. I don't care if it tests good. Tomorrow it could start leaking. It's the old saying "pay me now or pay me later". I'd rather minimize the risk by changing them out.

And yes, some capacitor stock COULD be old. MAYBE 10 years. But guaranteed it hasn't been sitting around for 30 years if it's a legitimate source and not someone's stock sitting in a garage.

*faints dead away* Yup... capacitors are livestock; just like batteries they grow old and feeble and die with no other factor but time.

mnem
"9. Capacitors are Murphy's footsoldiers." ~The 10 11 Laws of TEA

[med6753]

I had to rebuild my 190VDC reference. For some reason the original LR8N3-G regulator decided to give up the ghost. I might have accidentally shorted it. Anyway, new regulator and it's back up.

It's not the greatest reference in that the regulator is spec'ed to 5% so it does bounce around. But it's suitable for spot checks.

You DO love your 8505A, don't you?     

I take it to bed with me every night. 

[Neomys Sapiens]

I'd argue that once Japan got their corrosion problems under control, they proceeded to make some of the most reliable cars in existence. Which Ford never, ever, have managed, starting with the Taunus and Granada, where the order of the day is fill up on engine oil and check the fuel   

We have a saying here, that goes:
'Mit dem Ford fort, mit dem Zug zurueck!'