Test Equipment Anonymous (TEA) group therapy thread

[med6753]

Yep same observation here. 

Yea, I thought so. The 4XX series Teks are loaded with 1 uf, 2.2uf, 4.7uf, 6.8uf and 10uf tants and rarely does one short out. I think for future reference going to "risk" leaving them alone. Seems to be working so far.

[bd139]

I’ve had a 10uF go but not smaller ones. That went dead short so was quite easy to find. Also watch out as some of them are brown and look like silver micas. That kept me busy with that 7L12 for far too long.

[SilverSolder]

More than a few decades to go back to such a situation, surely? The 1960s, 70s, and early part of the 80s were the most militant era for the unions (until Thatcher destroyed their power).

Rather amusingly, the exchange rate graph clearly shows the pound losing most of its value in the first decade or so of our membership in the EU (then the EEC ofc).

Naturally some would see that as causation rather than mere correlation, but even a die-hard anti-EUer like me can see deeper than that   

What that graph is showing, more than anything else, is a crushed post-war Germany growing into the foremost economic power in Europe.

Agreed.  It might also be showing Britain moving from an Empire economy to relying on its own resources -  a big transition that was bound to hurt.

[mnementh]

As a kid, Monday evening meal was always cold cuts plus bubble and squeak.

Tuesday was rissoles...

Ooh I want kidney bean rissoles now. I accidentally ordered 8 cans of kidney beans from Ocado and have only made chilli so far. Thanks for inspiration.

Ifni save me; the first time I scrolled down this post, I read it as "Bubbles Tuesday with squeaky kidney bean assholes..."

mnem
Bubbles is back in town, and he's looking for you...

[Cerebus]

I've noticed some trends with failures on beaded tants. With some exceptions values 10uf and lower seem to hold up well. It's the 15uf to 47uf tants that seem to fail the most. With 47uf being the worst of all. Has anyone else noticed this?

Yes. I suspect that it's down to physical volume. Crudely, capacitance * voltage rating ~ volume. When you're making small caps there's less room for optimising the quantity of materials you're using, as the caps get physically bigger it become easier to minimise the volume of materials used. You've probably got a fixed mechanical tolerance you can work to, on a small cap this might represent 10% of the value, on a large cap 1% of the value, so for small caps you have to play safe and aim for the high side of your tolerances. For larger caps you can get 'closer to the wire'. To put it differently, based on fixed physical tolerances, a 1uF 6.3V cap the voltage tolerance might^* be +2V, on a 47uF 25V cap the voltage tolerance might also be +2V, so you get +32% and +8% voltage tolerance respectively.

Once you get bigger than some specific size your intended physical tolerance gets bigger than your quantum of physically achievable tolerance and it becomes a controllable parameter again. Hence that hump in the middle.

^*Totally made up figures.

[med6753]

First impressions with the Hakko....

625 degrees not quite enough for this double sided board especially on ground planes.

725 degrees much better for quick on and off.

[Specmaster]

First impressions with the Hakko....

625 degrees not quite enough for this double sided board especially on ground planes.

725 degrees much better for quick on and off.

I hope thats F and not C your talking there?

[med6753]

First impressions with the Hakko....

625 degrees not quite enough for this double sided board especially on ground planes.

725 degrees much better for quick on and off.

I hope thats F and not C your talking there?

C of course! 

Got the potential offenders removed and new installed. Forgot all about the four 100uf/25V tants on that board. Oh well, will catch them when I change the electrolytics. Going back together.

[tggzzz]

First impressions with the Hakko....

625 degrees not quite enough for this double sided board especially on ground planes.

725 degrees much better for quick on and off.

I hope thats F and not C your talking there?

C of course! 

Got the potential offenders removed and new installed. Forgot all about the four 100uf/25V tants on that board. Oh well, will catch them when I change the electrolytics. Going back together.

Then the 22uF 15Vbuggers will get you. Hope you have an 86.6ohm resistor available

[med6753]

First impressions with the Hakko....

625 degrees not quite enough for this double sided board especially on ground planes.

725 degrees much better for quick on and off.

I hope thats F and not C your talking there?

C of course! 

Got the potential offenders removed and new installed. Forgot all about the four 100uf/25V tants on that board. Oh well, will catch them when I change the electrolytics. Going back together.

Then the 22uF 15Vbuggers will get you. Hope you have an 86.6ohm resistor available

You can never be 100% unless you want to spend your life (and bank account) changing tants. Life is not without risks. 

Anyway, the 485 is back together and powered up with no smoke. Mission accomplished. Tomorrow do the final compensation adjustments and frequency checks. The remaining caps to be changed will be ordered and on hand for future change out.

[tggzzz]

First impressions with the Hakko....

625 degrees not quite enough for this double sided board especially on ground planes.

725 degrees much better for quick on and off.

I hope thats F and not C your talking there?

C of course! 

Got the potential offenders removed and new installed. Forgot all about the four 100uf/25V tants on that board. Oh well, will catch them when I change the electrolytics. Going back together.

Then the 22uF 15Vbuggers will get you. Hope you have an 86.6ohm resistor available

You can never be 100% unless you want to spend your life (and bank account) changing tants. Life is not without risks. 

Anyway, the 485 is back together and powered up with no smoke. Mission accomplished. Tomorrow do the final compensation adjustments and frequency checks. The remaining caps to be changed will be ordered and on hand for future change out.

Indeed, but a15V tant on a 13V rail?

[med6753]

First impressions with the Hakko....

625 degrees not quite enough for this double sided board especially on ground planes.

725 degrees much better for quick on and off.

I hope thats F and not C your talking there?

C of course! 

Got the potential offenders removed and new installed. Forgot all about the four 100uf/25V tants on that board. Oh well, will catch them when I change the electrolytics. Going back together.

Then the 22uF 15Vbuggers will get you. Hope you have an 86.6ohm resistor available

You can never be 100% unless you want to spend your life (and bank account) changing tants. Life is not without risks. 

Anyway, the 485 is back together and powered up with no smoke. Mission accomplished. Tomorrow do the final compensation adjustments and frequency checks. The remaining caps to be changed will be ordered and on hand for future change out.

Indeed, but a15V tant on a 13V rail?

I remember which one you are talking about from the other 485. Not to worry, I will change it.

[Specmaster]

Meanwhile, in other news, of topic but is of general interest to a lot of members, I have just stumbled across on YouTube a concert which is excellent, for those fans, the link is below should you wish to check it out.

[med6753]

There's also a band here in the States that does Floyd too and I've been told they are pretty good.

But in my mind nothing beats the real Gilmour/Waters/Wright/Mason. 

[Specmaster]

That is so true, but I'm watching this and being impressed on their take on their music, worth a look I think 

[med6753]

I still have the "Pulse" VHS tape and luckily a Toshiba VHS 4 head deck that still works. 

[bd139]

Damn I had pulse special boxed edition CDs (with flashing LED) and some fucker snatched my bag at the time. I was more pissed about that than the laptop (which was a shit Compaq that was sooo heavy)

[Specmaster]

I still have the "Pulse" VHS tape and luckily a Toshiba VHS 4 head deck that still works. 

You really ought to get that digitised onto a DVD ASAP to preserve it longer.

[Specmaster]

Damn I had pulse special boxed edition CDs (with flashing LED) and some fucker snatched my bag at the time. I was more pissed about that than the laptop (which was a shit Compaq that was sooo heavy)

Thats a real bummer.

[profanum429]

Well, had a low ball offer accepted on a HP 89410A, guess I own a giant VSA now.

[nfmax]

So plan this week is beef, tomato and lettuce sandwiches tomorrow for lunch. I'll do myself a nice stir fried beef thing on Tuesday. Then beef masala on Wednesday in the slow cooker.

I reccomend roast beef, mustard, and spring onion sandwiches. Use butter. Gives a nice sharp bite to it!

[med6753]

Damn I had pulse special boxed edition CDs (with flashing LED) and some fucker snatched my bag at the time. I was more pissed about that than the laptop (which was a shit Compaq that was sooo heavy)

I have that CD too. 

Edit, here it is. The batteries died years ago and I suppose I could get in there and change them.

[SilverSolder]

So plan this week is beef, tomato and lettuce sandwiches tomorrow for lunch. I'll do myself a nice stir fried beef thing on Tuesday. Then beef masala on Wednesday in the slow cooker.

I reccomend roast beef, mustard, and spring onion sandwiches. Use butter. Gives a nice sharp bite to it!

Coleman's mustard.  Few other brands seem to have the right level of aggression!

[bd139]

Damn I had pulse special boxed edition CDs (with flashing LED) and some fucker snatched my bag at the time. I was more pissed about that than the laptop (which was a shit Compaq that was sooo heavy)

I have that CD too. 

Edit, here it is. The batteries died years ago and I suppose I could get in there and change them.

That's the one.

Well I just spent 2 fucking hours debugging an RF amplifier to find out the LED I was using as a zener had an 0.8V voltage drop. It's supposed to be 2V. Fucks sake. Those were decent LEDs as well from RS. In the process of debugging I managed to blow up the NanoVNA as well

Just about had enough of shit today 

[mansaxel]

Coleman's mustard.  Few other brands seem to have the right level of aggression!

I prefer Bournier. In my opinion the best Dijon. When I'm making a local variant on the Reuben James, though, I prefer French's yellow, or a very good clone that is a lot easier to get in Sweden. It's known by the name "S-sandwich" because it only allows ingredients starting with "S" in Swedish; sourdough bread, butter ("smör"), salt boiled beef, sauerkraut, mustard ("senap"), and chopped celery ("selleri"). Insanely tasty.  Now I'm hungry, and I lack all the ingredients.