Test Equipment Anonymous (TEA) group therapy thread

[grizewald]

...Also a reasonable grasp of chemistry is required to satisfy my small boy's interest in rapid exothermic reactions.

That takes me back. Potassium permanganate and glycerine in a test tube made a great smoke bomb for setting off inside an old style BT phone box. Even more fun was constraining the reaction inside a thick glass fizzy drinks bottle and lobbing said bottle as far as possible once the first signs of the reaction starting were seen. The resulting bang was shockingly loud! 

[mnementh]

In fact all the food items for sale were at normal stock levels apart from those already mentioned.

Is the nation planning to live on pasta in rice gruel while they sob into their huge stack of tissues and toilet rolls?

People buying things other people have been seen buying because hysteria. My storage (which is always at or close to these levels) will see us good through two or three weeks with some (but not at rice-only levels) boredom in selections. We've got cooking and lighting methods independent of mains supply, and there is a plan for water.

I do not expect neither mains nor water supply running out, because most of these functions can be operated with skeleton staff.

We're out of TP. Going to COSTCO in an hour or so. Pray for me. 

mnem
Now where did I put my mace and TASER...?

[med6753]

To take our minds off the gloom and doom....and absolute stupidity for a moment I did some more troubleshooting on the 485 and I made progress but it is pointing towards an apocalypse.

See schematic. If I pull either Q686 and Q688 (BTW, both test OK) the scope powers up. That can really only point to one thing. U660. Somehow I damaged it (and the one on the other board too) probably due to this mystery nylon washer which I never saw nor does the manual give any direction on proper installation. U660 is unobtanium.

As a last resort I may try to find a suitable nylon washer and give it a try. But I don't hold out much hope it will make any difference.


Oh well. Gotta take the occasional loss. Can't win them all.     

What happens if you pull Q682?

Dunno and at this point don't care. Scope is re-assembled and put back into it's cabinet and tossed in the TE closet to possibly look at sometime in the future. Or never. Or if I find a parts unit REAL cheap I'll use that one as a basis to Frankenstein a good one. Have bigger fish to fry right now with projects that will yield results and not frustration.   

[mnementh]

Good morning, sunshine. Any skidmarks today...?     Just wanna be ready when Spec bd decides to unload that 'scope... 

mnem
*agitating-ily*

[med6753]

Good morning, sunshine. Any skidmarks today...?     Just wanna be ready when Spec decides to unload that 'scope... 

mnem
*agitating-ily*

If you must know I'm squeaky clean and the roids are not swollen and pain free. 

Don't you mean when bd decides to unload that scope? Is you confused? 

[mnementh]

Good morning, sunshine. Any skidmarks today...?     Just wanna be ready when Spec decides to unload that 'scope... 

mnem
*agitating-ily*

If you must know I'm squeaky clean and the roids are not swollen and pain free.     Don't you mean when bd decides to unload that scope? Is you confused? 

  Yes, you're absolutely right; duly noted and corrected. I blame an excess of blood in my caffeine circulatory system. 

mnem
No need to show me; a simple verbal report will do. 

[AVGresponding]

@beanflying, that's a nice looking meter, glad it's in on the dark side of the earth and I can't afford the shipping!   


@Specmaster, mansaxel, tautech,
Well I have the HP differential probe when I build a psu for it... but it still needs 10x and 100x tips.


I've done some measurements, and there's no continuity between the -ve o/p and earth.
However, when powered on there's 4.6VAC and -440mVDC between earth and -ve. I suspected Y cap coupling so I pulled it apart to look:



Ha bloody ha, VWR   
Ok lets take out some more screws, all machine thread, incidentally:



In like Flynn!

It's a switcher alright, which was pretty obvious from the lack of heft. The small black relay on the bottom left is the o/p switch, it's a DPCO, and isolates both -ve and +ve (all 4 pairs of o/p are paralleled, and it can be seen that set 4 is the first off the board, if I need to use the full current).
Probing the i/p side of the -ve rail on the relay (all the tp's seem to be gold plated, nice) gives a bit over 20Mohms to ground in either polarity, so I'm calling Y cap + high value resistor between earth and -ve.

In the absence of a diff probe I'll just use two probes and A-B, but given it's a switcher I'm not overly optimistic. On the other hand, it has bigger caps on the o/p than you'd see on a lab bench supply, so maybe it'll not be too bad. After all, max current is only 500mA so it shouldn't need a huge amount of decoupling.

It takes forever to ramp the V up in constant current mode; maybe because I set the current so low, 3mA since I don't have a suitable high current load to use at 300VDC. It took 4 minutes to stabilise to 157VDC @ 3mA into a 47k resistor.


The bluetooth audio module arrived just now, so I might take a few meters apart this weekend to see which I can hack it into:

[mnementh]

K... I'm off to COSTCO. If I'm not back in 4 hours, send out the rescue dogs.



mnem
 

[Brumby]

... with toilet paper.

[URI]

Corona virus has now infected Germany as a hole; school shutdown, home office, cancelled events/soccer games.
A N D:
Sold out Toilet paper (4 layer soft variant, 3 layer will be sold out soon..), kitchen roll, pasta, rice, laundry hygiene rinser and: plain soap (solid bar).   
We ran out of soap (ok, we took the last bar of soap from our stock) and I simply wanted to restock oner or two bars ... no hamstering.

This Pasta thing is remarkable: Empty shelves where the pasta sat and right next to it full shelves with pasta sauce!? 
Also no shortage of fresh milk products, fresh fruits and vegetables or canned fruit, canned vegetables or canned soups/stews.
So no problem in that department for me.   

Cool Nixie counter. Not at that price but very stylish  eBay auction: #143542015353

And now on to something completely different...   

This is indeed a very stylish piece of TE. Design icon (Designikone) was the first thought that struck me.
Not only the flat form factor (seems to be only 1HE high) but also the design of the slide switches, the front in that area or the knobs looks like it was holisticly designed not by an engineer but a true designer. Wow.   

I'm no Nixie fan boy but I do recognise the effort of squeezing those tubes in that flat housing.     

Mnem, I hope you can get hold of some toilet paper without too much fightingeffort.   

[Mr. Scram]

I was genuinely a bit embarrassed to buy bog rolls today. I ran out, I swear!

[AVGresponding]

Corona virus has now infected Germany as a hole; school shutdown, home office, cancelled events/soccer games.
A N D:
Sold out Toilet paper (4 layer soft variant, 3 layer will be sold out soon..), kitchen roll, pasta, rice, laundry hygiene rinser and: plain soap (solid bar).   
We ran out of soap (ok, we took the last bar of soap from our stock) and I simply wanted to restock oner or two bars ... no hamstering.

This Pasta thing is remarkable: Empty shelves where the pasta sat and right next to it full shelves with pasta sauce!? 
Also no shortage of fresh milk products, fresh fruits and vegetables or canned fruit, canned vegetables or canned soups/stews.
So no problem in that department for me.   

Cool Nixie counter. Not at that price but very stylish  eBay auction: #143542015353

And now on to something completely different...   

This is indeed a very stylish piece of TE. Design icon (Designikone) was the first thought that struck me.
Not only the flat form factor (seems to be only 1HE high) but also the design of the slide switches, the front in that area or the knobs looks like it was holisticly designed not by an engineer but a true designer. Wow.   

I'm no Nixie fan boy but I do recognise the effort of squeezing those tubes in that flat housing.     

Mnem, I hope you can get hold of some toilet paper without too much fightingeffort.   

Yep, they just announced here that English and Scottish Premier league football is cancelled.

That nixie counter reminds me of designer hi-fi from the late 60s/ early 70s.


EDIT: Forgot to link this in, one for the US folks to chase:
https://www.ebay.co.uk/itm/Heathkit-Capacitor-Checker-Model-IT-28/264664889907

[Cerebus]

That nixie counter reminds me of designer hi-fi from the late 60s/ early 70s.

That "sliding horizontal control thing" has a very Bang and Olufsen feel to it.

[URI]

That nixie counter reminds me of designer hi-fi from the late 60s/ early 70s.

That "sliding horizontal control thing" has a very Bang and Olufsen feel to it.

..like this one?:

[bd139]

I can hear the crackling already from those slide switches

[factory]

Cool Nixie counter. Not at that price but very stylish  eBay auction: #143542015353

And now on to something completely different...   

This is indeed a very stylish piece of TE. Design icon (Designikone) was the first thought that struck me.
Not only the flat form factor (seems to be only 1HE high) but also the design of the slide switches, the front in that area or the knobs looks like it was holisticly designed not by an engineer but a true designer. Wow.   

I'm no Nixie fan boy but I do recognise the effort of squeezing those tubes in that flat housing.     

Added that to my watch list a few days ago, as well as being a stylish 9 digit counter, it goes to 12.4GHz.
Shame about the silly price, I imagine a manual for it would be unobtainable too and GSP would bust all those slide controls off.

David

[med6753]

Some projects are simple and mundane. This is one of them. Tek 500 Series plug-ins are exposed to dust, dirt, and critters unless they are plugged into a mainframe or a 500 Series cart with slots for spare plug-in's. Since I have 2 plug-in's and one 535A that means the spare is exposed. No longer. Some scrap lumber and a bit of stain and it has it's own protective enclosure.   

[Specmaster]

... with toilet paper.

Just got back a quick trip to see what shopping I could get from our Sainsbury's and Asda stores. I could have taken loads of photos of the shelves, but they would look similar to the attached, Sainsbury's tinned vegetables and soaps etc and Asda toilet rolls shelves, photo shows but a small section of that rack, not a single toilet roll left of any size or description 

[AVGresponding]

That nixie counter reminds me of designer hi-fi from the late 60s/ early 70s.

That "sliding horizontal control thing" has a very Bang and Olufsen feel to it.

I don't think it was B&O I was thinking of, though since I just spent 20 minutes searching google images without luck, I can't be sure.
It's the chin that sticks in my memory.

The image searching did remind me of a couple of things; I really love the look of Pioneer blue line stuff, and that I have a Leak Delta 30 amp that could do with restoring.

It works, after a fashion; I got it given in the 1990s by a guy I was buying some speakers off. One channel was down, and I traced it to a duff transistor in the preamp stage.
Nice thing about these old things is they are 100% discrete through hole, and also the channels are on their own cards mounted onto a push connect backplane.
I was still a noob back in those days in many ways, and just swapped the duff one out for something like a BC337 or 2N3053 or something, icr, just to get it running.
Needless to say, the channels don't balance... would be nice to try and fix it properly now that I have the gear to do it.

[BU508A]

K... I'm off to COSTCO. If I'm not back in 4 hours, send out the rescue dogs.

[Specmaster]

That nixie counter reminds me of designer hi-fi from the late 60s/ early 70s.

That "sliding horizontal control thing" has a very Bang and Olufsen feel to it.

I don't think it was B&O I was thinking of, though since I just spent 20 minutes searching google images without luck, I can't be sure.
It's the chin that sticks in my memory.

The image searching did remind me of a couple of things; I really love the look of Pioneer blue line stuff, and that I have a Leak Delta 30 amp that could do with restoring.

It works, after a fashion; I got it given in the 1990s by a guy I was buying some speakers off. One channel was down, and I traced it to a duff transistor in the preamp stage.
Nice thing about these old things is they are 100% discrete through hole, and also the channels are on their own cards mounted onto a push connect backplane.
I was still a noob back in those days in many ways, and just swapped the duff one out for something like a BC337 or 2N3053 or something, icr, just to get it running.
Needless to say, the channels don't balance... would be nice to try and fix it properly now that I have the gear to do it.

Agree 100% with getting that Leak restored, they were really nice bits of kit back in the day, considered to be comparable to a Rolls Royce of Hi-fi amplifiers, those and Quad amps.

[Cerebus]

Seriously ?   

[Specmaster]

That nixie counter reminds me of designer hi-fi from the late 60s/ early 70s.

That "sliding horizontal control thing" has a very Bang and Olufsen feel to it.

I don't think it was B&O I was thinking of, though since I just spent 20 minutes searching google images without luck, I can't be sure.
It's the chin that sticks in my memory.

The image searching did remind me of a couple of things; I really love the look of Pioneer blue line stuff, and that I have a Leak Delta 30 amp that could do with restoring.

It works, after a fashion; I got it given in the 1990s by a guy I was buying some speakers off. One channel was down, and I traced it to a duff transistor in the preamp stage.
Nice thing about these old things is they are 100% discrete through hole, and also the channels are on their own cards mounted onto a push connect backplane.
I was still a noob back in those days in many ways, and just swapped the duff one out for something like a BC337 or 2N3053 or something, icr, just to get it running.
Needless to say, the channels don't balance... would be nice to try and fix it properly now that I have the gear to do it.

Agree 100% with getting that Leak restored, they were really nice bits of kit back in the day, considered to be comparable to a Rolls Royce of Hi-fi amplifiers, those and Quad amps.

I think that the B&O unit your thinking of was the 901 as below?

[AVGresponding]

Nope.

The half-remembered hifi I'm thinking of had a chin across the front with controls on it.


EDIT: Won the AMD V5900 on my maiden bid, though not quite in mnementh-jamminess territory in terms of price. Ordered a dp > hdmi adaptor from a UK seller on ebay, the race is now on to see which arrives first!

[bd139]

That's one ugly motherfucker that is.

I'm thinking about building myself an amp with one of these at the moment: http://www.ti.com/product/TPA3245

(either that or a nice pair of active speakers with fully analogue signal processing instead of passive crossover networks)