Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

... instead used one of the most corrosive things she could have used, salt, so with that and...

Your blood, and most intra-cellular and extra-cellular fluids are 0.9% salt so, if salt were corrosive to bodily matter you'd fall apart in pretty short order.

I'm not so sure on that, neat salt brushed directly onto the teeth and into the gums? I'm no expert but that sounds highly abrasive to me wearing down the enamel and creeping beneath the gumline?

Corrosive? Abrasive? Which are you going for? BTW, salt as a dentifrice is as old as the hills. Soot and salt was a traditional, if odd sounding, toothpaste.

Don't they scream and fizz a lot.

[neo]

Was it on a negative voltage rail or something? In such a case, of course, ground is positive.

Two important bits to note,
It is on a negative rail but it is completely unmarked except for in the manual.
When i do something stupid i am extremely hard on myself..... even if it doesn't ultimately matter.


The cap blew itself to smithereens, had to use an ounce of IPA to get the crud back off besides wasting a 2 dollar capacitor and that 2 dollar capacitor with shipping is a 7 dollar capacitor. But nothing more expensive than that blew up.... that i know of yet.

[bitseeker]

Ah, OK. Glad it was just the capacitor. As for shipping, yeah, it's kind of a bummer for small quantities. It's also a pain trying to cluster parts needs in order to make a worthwhile order.

[Specmaster]

Was it on a negative voltage rail or something? In such a case, of course, ground is positive.

Two important bits to note,
It is on a negative rail but it is completely unmarked except for in the manual.
When i do something stupid i am extremely hard on myself..... even if it doesn't ultimately matter.


The cap blew itself to smithereens, had to use an ounce of IPA to get the crud back off besides wasting a 2 dollar capacitor and that 2 dollar capacitor with shipping is a 7 dollar capacitor. But nothing more expensive than that blew up.... that i know of yet.

I did surmise that you managed to blow the cap, hence your comment about $7, but don't be too hard on yourself, I think we have all done that or similar things at some point in our time, especially as the circuit board was not marked. Chalk it up one of life's experience and a lesson to double check next time.   

[neo]

Was it on a negative voltage rail or something? In such a case, of course, ground is positive.

Two important bits to note,
It is on a negative rail but it is completely unmarked except for in the manual.
When i do something stupid i am extremely hard on myself..... even if it doesn't ultimately matter.


The cap blew itself to smithereens, had to use an ounce of IPA to get the crud back off besides wasting a 2 dollar capacitor and that 2 dollar capacitor with shipping is a 7 dollar capacitor. But nothing more expensive than that blew up.... that i know of yet.

I did surmise that you managed to blow the cap, hence your comment about $7, but don't be too hard on yourself, I think we have all done that or similar things at some point in our time, especially as the circuit board was not marked. Chalk it up one of life's experience and a lesson to double check next time. 

My first time popping a cap believe it or not...

[Specmaster]

I believe it, don't they make you jump as well?

[tautech]

Was it on a negative voltage rail or something? In such a case, of course, ground is positive.

Two important bits to note,
It is on a negative rail but it is completely unmarked except for in the manual.
When i do something stupid i am extremely hard on myself..... even if it doesn't ultimately matter.


The cap blew itself to smithereens, had to use an ounce of IPA to get the crud back off besides wasting a 2 dollar capacitor and that 2 dollar capacitor with shipping is a 7 dollar capacitor. But nothing more expensive than that blew up.... that i know of yet.

I did surmise that you managed to blow the cap, hence your comment about $7, but don't be too hard on yourself, I think we have all done that or similar things at some point in our time, especially as the circuit board was not marked. Chalk it up one of life's experience and a lesson to double check next time. 

My first time popping a cap believe it or not...

To use Specmaster's sig:

That bl**dy Murphy is always watching waiting for a chance to strike ! 

[neo]

I believe it, don't they make you jump as well?

It takes alot to make me jump, this didn't. Then again it was buried in the instrument and i was too busy trying to flip it off. 

[Cerebus]

My first time popping a cap believe it or not...

I thought a while before I posted this. So far, I have never managed to make a cap pop accidentally. I've nuked a few resistors, and quite a few semiconductors, but never a cap.

I will now tip-toe around for the next few weeks, waiting for Murphy to catch up with me.

Edited to add: On thinking about it, I have had bloody Riva X-class caps go on me, but that doesn't count as it's not through application of my own stupidity.

[Brumby]

My first time popping a cap believe it or not...

I thought a while before I posted this. So far, I have never managed to make a cap pop accidentally. I've nuked a few resistors, and quite a few semiconductors, but never a cap.

I could say the exact same ... but ... this is why I won't:

I will now tip-toe around for the next few weeks, waiting for Murphy to catch up with me.

 

[bitseeker]

Likewise. I get enough of a reminder from old tantalum caps shooting into the air when powered correctly.

[bd139]

My first time popping a cap believe it or not...

I thought a while before I posted this. So far, I have never managed to make a cap pop accidentally. I've nuked a few resistors, and quite a few semiconductors, but never a cap.

I will now tip-toe around for the next few weeks, waiting for Murphy to catch up with me.

Edited to add: On thinking about it, I have had bloody Riva X-class caps go on me, but that doesn't count as it's not through application of my own stupidity.

I’ve had lots of them go on me:

1. A few mistakes when I was a kid and had no idea what I was doing. This was interesting because most of the ones I played with back then were axial and chassis cans extracted from old radios which have comedic levels of venting ie none. Experiment number 412.  Connect capacitor across AC winding. Result: hole in nan’s curtains.
2. A few not paying attention and not owning a current limiting supply. . One bounced off my head.
3. I suppose this counts but assuming that the line on an SMD tant was negative

And the most important:

4. Hundreds of sacrifices to the Flying Spaghetti Monster just because sacrificing them is fun. I will occasionally buy a bag just to blow up! Better entertainment than a Netflix sub.

Rifa X class are the suicide bombers in the rebellion against my sacrifices. They’ve got me twice now.

[beanflying]

How many volts does it take to blow a 500v electro 

Having beer and lots of nibbles in the late afternoon sun 

[bd139]

Not many volts if you use it wrongly

[beanflying]

I have a leftover lot of rather large unvented ones and I am about to salvage a Microwave

[bd139]

It's your moral obligation to add a large vent to each capacitor via the application of volts

[BravoV]

Touch down, its here ... 

Only the unit, printed manual and power cord only.    No probe. 

[bd139]

Ooh that looks interesting. Let us know how it goes. I am looking out for an SA at the moment so might be another thing to add to the "look out for" list.

Edit: boo hiss. Looks like a couple of resistors have burned as well. Might have to rebuild the vertical amp and test it properly outside the scope    Smells "interesting".

Replying to myself here on the Tek 465 ... it is operational again after a 2 hour replacement job. Looks like the transistor just gave up. There was no other damage other than to a resistor. I didn't have a suitably rated or valued one so I used two in parallel and that worked fine. There was a moment of annoyance when it showed large trace distortion so I pulled the transistor and measured hfe (DT830 FTW) and it was way off for that transistor. So I chucked another one in and it was fine. The one with the knackered hfe I'd already had on a breadboard so it might have been slightly toasted or zenered.

[neo]

Ooh that looks interesting. Let us know how it goes. I am looking out for an SA at the moment so might be another thing to add to the "look out for" list.

Edit: boo hiss. Looks like a couple of resistors have burned as well. Might have to rebuild the vertical amp and test it properly outside the scope    Smells "interesting".

Replying to myself here on the Tek 465 ... it is operational again after a 2 hour replacement job. Looks like the transistor just gave up. There was no other damage other than to a resistor. I didn't have a suitably rated or valued one so I used two in parallel and that worked fine. There was a moment of annoyance when it showed large trace distortion so I pulled the transistor and measured hfe (DT830 FTW) and it was way off for that transistor. So I chucked another one in and it was fine. The one with the knackered hfe I'd already had on a breadboard so it might have been slightly toasted or zenered.

Nice fix, it is nice to see one so simple. 

I've reached a point of fixing everything to such an extent that all i have left are annoying bastards and cosmetics. Cue the part of me ordering a 7A18 just for it's knobs.

[bd139]

Ah yeah it's annoying when it gets there. I'm actually having a clear out of dead stuff I'm never getting around to fixing. The near house move actually outlined how bad it was.

Many years ago I lost a battle against a Tek 453 and I'm considering buying another one so I can win that battle again. That's when it gets trouble

[neo]

Many years ago I lost a battle against a Tek 453 and I'm considering buying another one so I can win that battle again. That's when it gets trouble

Given that this is TEA i'm going to take a leap and say buying is definitely encouraged. 

[Specmaster]

Ah yeah it's annoying when it gets there. I'm actually having a clear out of dead stuff I'm never getting around to fixing. The near house move actually outlined how bad it was.

Many years ago I lost a battle against a Tek 453 and I'm considering buying another one so I can win that battle again. That's when it gets trouble

Congrats on your victory with the 465 although TBH, it never stood a chance against you. So you want to relive your battle with a 453 then eh. well has it happens there is one on sale that might just give you a challenge, and the biggest one would be the asking price I reckon https://www.ebay.co.uk/itm/TEKTRONIX-TYPE-453-OSCILLOSCOPE/222866547423?hash=item33e3e1a2df:g:QlEAAOSw2C1am~Mj 

[bd139]

Ooh now that's suitably manky looking. Not sure why my script didn't pick that one up!

Asking price is way too high for the condition. I'd expect £35 for that including delivery. It's missing CRT graticule cover and the panel cover so will probably skip that.

If you've ever peered into one of them they are bang in the middle of the solid state twilight zone. No tubes (apart from some very early models and then only the amp impedance buffers and they are nuvistors) and no ICs either.

[Specmaster]

Haha, that was my reaction when I saw it, the best use for that is a boat anchor, it made my 1740A look like it was new by comparison.

[bd139]

Yep they are boat anchors. There is the 454 of course which was a bit of a break through. 150Mhz bandwidth in a portable scope in 1968 (!). I might hang out for one of the actually.

They are built like apollo space craft. Cast, machined, neatly wired, incredibly well documented, the lot. Gold plated everything. Designed to withstand drops!

Vertical amplifier



More pictures: http://www.helo.de/helo/tek/portable/454/454_e.htm

http://elektronikbasteln.pl7.de/reparatur-eines-tektronix-454-oszilloskop-150-mhz.html