Test Equipment Anonymous (TEA) group therapy thread

[Cerebus]

I should find out where he lives and stab his tyres early in the morning 

In other news, frozen pigs just flew out of hell… it looks like it actually works.

Have ID’ed the probe sensor doesn’t work properly on one of the channels but that’s an easy fix. Might even work with a clean.

Now now, no criminal damage... the same effect more or less can be achieved with small bits of wood ie matchsticks, jammed into the valve. It lets all the air out, but doesn't damage anything. Or you can use a Schrader tool to loosen the valve core, to the same effect.

That still counts as criminal damage.

The damage caused as a result of the offence does not have to be permanent. As long as the damage caused affects the value or performance of the property,  this is sufficient to be classed as an act of criminal damage.

Examples of criminal damage ... Smearing mud on the walls of a police cell

If there's any work involved in correcting what's been done, or if it [temporarily] affects the ability to use the property it counts as damage.

Letting air out of tyres might even count as aggravated criminal damage as it introduces an element that might cause physical injury to a person.

[Specmaster]

Hopefully not an anal probe...


@Robert if you don't mind sharing, what did you offer on the Keithley 199? (no I'm not still annoyed that you beat me to the punch     )

£110.
If you want it I can pass it on unopened......

That's pretty good. No, it's ok thanks, as I said earlier my eyes are bigger than my wallet at the moment. Would you believe that we are still waiting to receive last year's pay rise, never mind this year's. When that eventually arrives I'll be in a less uncomfortable position...

Yes, I'd believe it, that's the way it is in the public sector, even if they say you have a pay rise, actually getting it is another thing, but it gives the Westminster mob another lie to sprout.

[Robert763]

New TEA
What could it be?

It's a General Radio 2220 Bug Hound. Used for tracing shorts and opens in PCBs and wiring. also good for genearl circuit tracing.
Unlike similar tools like ToneOhm and the HPP current tracer probe it uses AC signals and a phase sensitive detector. I'm looking forward to using it in anger.

So non-contact, or just very tiny current so as not to blow up stuff like the ShortSqweek and Huntrons?

mnem
 

Both.
Non-contact probe with LEDs to show current direction and contact with +- 50uV or 500uV

[McBryce]

I received a very special package, which certain people on this forum should appreciate. 

Well that's nice, but it has 2 things wrong with it, 1/ it has a really crappy LCD screen which seriously detracts from its usability, poor resolution and contrast, 2/ It doesn't  have an = key 

The second, is not really a problem, just an inconvenience and requires a small rewire of one's brain in order to work it correctly, the first is in my view a major design flaw especially when the cost is taken into account, a few cents more on the BOM and it could have been a winner. 

mnem
mmmm... creamed spinach color...

Gamegear was great if your father happened to own a battery factory, otherwise it was just annoying to see the GB guys playing all day while your batteries were eaten by a power hungry CCFL backlight. If you want to use one today: Swap the failed caps that have stopped the sound from working. Swap the other failed caps that have caused the screen to be unviewable and then convert the backlight to LED. Only then can you even consider using it.

McBryce.

[Vince]

It's Systron Donner DMM, model 7005A with options; 01 auto ranging, 02 AC volts, 03 resistance & 04 DC mA. Ignore the markings in red for mV (option 07), you can't have this option if DC mA 04 is fitted, as they use the same connector.


David

No printer output on this one, it's another option, needs an extra board with the wiring loom & connector.

Looked at the specs, wow it's one hell of cool DMM for sure, I understand why you worked the seller so much to get him to ship it to you !
So much features and performance and 6 digits, packed in such a compact form factor, I guess  engineers and students arrived early in the morning to secure one of those for the day ! 

The printer board I guess you could make one yourself, if the schematic is available ? The board layout document will then be of great help to.... well, lay out the board 
Looks like a sophisticated printer output as well... it handles polarity, my Rochar does not    Maybe I can work on remedying that.... 

[grizewald]

So, here's the innards of the Datron 1071 as I received it. Everything is spotless and dust free due to the complete lack of fans.
[...]

Thanks for all those nice pictures. I've forwarded the URLs of your Datron 1071 to bitseeker for his list.

And for entertainment reasons, here is the list of the repair videos from FeedbackLoop of his Datron 1071.

#47 - Datron 1071 7.5-digit multimeter repair
#48 - Datron 1071 display replacement part 1
#51 - Datron 1071 display replacement part 2
#90 - Datron 1071 LED display
#92 - Datron 1071 LED display followup

There are some more to come! I also realised I'd posted them full size so I just went back and edited my posts to change the
images to 500 pixel previews. They're still clickable for the full size versions.

I remember watching feedback.loop's videos. What a shame he ended up with a duff display. I've since bought a very basic 1061
with no options just so that I have a parts mule with a spare display and some of the unobtanium components if I should ever need
them.

Just like the Solartron 7075 that I have, the gas discharge displays are so nice to look at, particularly if you have eyesight which is
as crap as mine is becoming.

[mnementh]

On the (Woodworking) Bench This Morning: Anniversary Project Table

   I ordered the "Sanding Discs by the Foot" packet from Amazon... free delivery in aboot a week, but it only cost $11. That's less than a dollar a inch! I know a lot of guys and gals who'd gladly pay that! 

Anyhoo... it has discs from 40 grit up to 1500 grit; so far I've used one 320 grit disc and have all the runs & orange-peel spots smoothed out. Next will be finish pass; I'm thinking 600 grit. Might do it tonight, but likelier tomorrow AM when it's semi-cool out there.

SO close...

Another couple rounds of sanding with 600 grit, another couple coats of urethane. The runs on the edge I could live with, and the few fisheye spots are very ignorable... but there are a good half-dozen bristles stuck in this coat, which really pisses me off as I splurged for decent name-brand brushes this go-round. 

Right now vacillating over whether to try foam brushes, or cheat and get a rattle-can of oil-based urethane for the final coats. Hopefully I'll be able to get those bristles out just sanding with 600 grit.

mnem
"That's not sawdust... it's man-glitter." ~me

[mnementh]

New TEA
What could it be?

It's a General Radio 2220 Bug Hound. Used for tracing shorts and opens in PCBs and wiring. also good for genearl circuit tracing.
Unlike similar tools like ToneOhm and the HPP current tracer probe it uses AC signals and a phase sensitive detector. I'm looking forward to using it in anger.

So non-contact, or just very tiny current so as not to blow up stuff like the ShortSqweek and Huntrons?

mnem
 

Both.
Non-contact probe with LEDs to show current direction and contact with +- 50uV or 500uV

Ooooooh... does indeed sound like the PCB debugging Holy Grail. I can see why you're so pleased to find one. 

*adds another "must-have" to his watchlist... and slides it right up to the top*

mnem
Damn you Robert! Damn you to... New Jersey!!!

[Brumby]

Damn you Robert! Damn you to... New Jersey!!!

To New Jersey?  That's a bit harsh.  (Not that I've been there, but the reputation I've heard of is not stellar.)

[mnementh]

I should find out where he lives and stab his tyres early in the morning 

In other news, frozen pigs just flew out of hell… it looks like it actually works.

Have ID’ed the probe sensor doesn’t work properly on one of the channels but that’s an easy fix. Might even work with a clean.

Now now, no criminal damage... the same effect more or less can be achieved with small bits of wood ie matchsticks, jammed into the valve. It lets all the air out, but doesn't damage anything. Or you can use a Schrader tool to loosen the valve core, to the same effect.

That still counts as criminal damage.

The damage caused as a result of the offence does not have to be permanent. As long as the damage caused affects the value or performance of the property,  this is sufficient to be classed as an act of criminal damage.

Examples of criminal damage ... Smearing mud on the walls of a police cell

If there's any work involved in correcting what's been done, or if it [temporarily] affects the ability to use the property it counts as damage.

Letting air out of tyres might even count as aggravated criminal damage as it introduces an element that might cause physical injury to a person.

Mmmmhmmm... so inconveniencing someone wealthy enough to own a car is criminal and prosecutable... but destroying lives and making it impossible for whole segments of the population to house or feed themselves, much less own a car, is okay because it's monopoly corporations and politicians doing it, so is just business as usual.

Does cast a stark contrast on the concepts of High Crimes and Misdemeanors vs The Golden Rule, doesn't it? 

EDIT:   That actually is even more perverse than I originally thought. Consider this all-too-possible scenario:
Entitled dickbag parks in a handicapped spot repeatedly; often enough that someone who actually has the permit notices. Said victim calls the cops and lets the air out of his tires so he can't get away before they arrive. At worst dickbag receives a ticket he can probably get out of if he hires a lawyer; handicapped victim actually faces criminal prosecution and jail time.   

mnem
we are fucking doomed.

[mnementh]

Damn you Robert! Damn you to... New Jersey!!!

To New Jersey?  That's a bit harsh.  (Not that I've been there, but the reputation I've heard of is not stellar.)

Worse, they have musical theater. 

mnem
"Please stop sinning while I'm singing..."

[mnementh]

I received a very special package, which certain people on this forum should appreciate. 

Well that's nice, but it has 2 things wrong with it, 1/ it has a really crappy LCD screen which seriously detracts from its usability, poor resolution and contrast, 2/ It doesn't  have an = key 

The second, is not really a problem, just an inconvenience and requires a small rewire of one's brain in order to work it correctly, the first is in my view a major design flaw especially when the cost is taken into account, a few cents more on the BOM and it could have been a winner. 

mnem
mmmm... creamed spinach color...

Gamegear was great if your father happened to own a battery factory, otherwise it was just annoying to see the GB guys playing all day while your batteries were eaten by a power hungry CCFL backlight. If you want to use one today: Swap the failed caps that have stopped the sound from working. Swap the other failed caps that have caused the screen to be unviewable and then convert the backlight to LED. Only then can you even consider using it.

McBryce.

LOL... I was a GG-head; loved me some Ecco. Batteries were only a problem if you minded carrying a spare set of NiCds (okay, 2 or 3 ) in your backpack.

My solution was a a bit ugly: 4-Cell "bump-packs" held in with gaffer tape. But I was damned if I was going to spend more for one of the PowerBack packs than I did for my GG, especially when I was already buying NiCds in bulk for my RC car habit. I also made an adapter that let me run my sub-C car packs plugged into the AC adaptor port. The GG was designed to run off 6-cells of NiCd power with the external battery wart or 6 alkaline batteries; it has a pretty broad operating voltage range (Until caps got leaky and the BL CCFL got old and started drawing twice the usual current). Using the saddle-packs almost doubled the runtime from a set of AA NiCds back in the day.

mnem
 

[mnementh]

   ...In other news, frozen pigs just flew out of hell… it looks like it actually works.

Have ID’ed the probe sensor doesn’t work properly on one of the channels but that’s an easy fix. Might even work with a clean.

For 20 quid...? Def territory!

mnem
 

[Brumby]

Definitely not down-under territory.   

Congratulations.

[m k]

I broke my half style +4.0 market glasses and new ones are full sized with different type of lenses where only center is the real zoom.
Why I see sort of diminished things with those glasses?

I can see closer with them but things are smaller and sort of unreal.
Is that a focal point or some brain thingy?

[grizewald]

More Datron 1071

As I said in my last post about this meter, there's no such thing as a perfect one when you're talking about something from the mid '70s.
Mine was no exception, and although the meter powered up straight away when I received it and seemed to give plausible results when
reading a few voltage references and precision resistors, it was obvious that the meter wasn't entirely happy. First task was to check the
infamous Philips blue electrolytics.



Sure enough, with one end freed from the PCB, they measured:

Des.        Printed    Actual         ESR
               Value       Value
C45        47μF        34μF           8.1Ω        (Furthest away in the photo)
C46        47μF        34μF           6.4Ω
C47        33μF        28μF           8.1Ω
C48        33μF        25μF           10.2Ω
C49        10μF        9.7μF          4.5Ω
C50        10μF        9.4μF          7.6Ω

The replacements from Kemet and Vishay were a bit of a squeeze, but had rather better parameters:

Des.  New        New
         Value       ESR
C45   50μF       0.22Ω
C46   49.7μF    0.22Ω
C47   32.2μF    1.38Ω
C48   31.5μF    1.44Ω
C49   11.7μF    0.55Ω
C50   11.7μF    0.55Ω



I then checked the various power rails and found out of tolerance voltages and excessive ripple,
so it was time to turn my attention to that area of the meter. This is where the fun starts!

The power supply is implemented on the board that runs across the rear of the meter. Between that and the
rear of the case, Datron also crammed in all of the boards that handle the optional outputs, the front/rear
relays and the two stacked toroid transformers. It's kind of packed in there as you can see from
the photo below.


The only way I could easily work on the power supply was to separate the rear of the case with all its
boards from the rear PCB and remove the analogue, digital and current boards so that I had clear access to the
solder side of the PSU. I wasn't keen on my chances of being able to put it all back together again without
extensive photo documentation of what plug went where - there are no identifying labels on any of the plugs
that connect everything together, so I took my time and took many photos along the way. Finally, the rear
of the case was free!



continues in next post (which will be after I've eaten some strawberries and cream )...

[Specmaster]

465 should clean up nicely. Wonder if it works. Plug was cut off everything on the stand

Good all the knobs and shafts look to be OK, not bent from being clobbered or dropped, so it should clean up very nicely indeed, looking good so far.

[bd139]

   ...In other news, frozen pigs just flew out of hell… it looks like it actually works.

Have ID’ed the probe sensor doesn’t work properly on one of the channels but that’s an easy fix. Might even work with a clean.

For 20 quid...? Def territory!

mnem
 

Not quite. Full clean and check out…

Issues with channel switching. Looks like dirty switches and possibly a duff probe on my part. Hmm.

[mnementh]

Greetings TEA folk!

It's been far too long since I was here last, mainly due to a serious lack of time due to work pressure. As I'm on a nice long vacation from work at the moment, I spent a few days catching up on things here (as best one can for 2000+ pages) and have thoroughly enjoyed myself.

Despite having been pretty much overloaded with work, my GAS problem has continued unabated.

Welcome back, BTW... it has been too long.

A while ago I bought this T-shirt for my daughter:   

It reminded me of our conversations about the Koloboks.   

mnem
*toddles off to shop some spray varnish*

[Specmaster]

Put some bananas in before the potatoes too

Solartron. Also works apart from two missing decimal points. I swapped a couple of the rather ancient LED displays around expecting that to be the issue but it wasn’t. Hopefully the main IC isn’t at fault 

Should read 9.6245.

Got to go do some shopping now 

If those LEDs are socket based, more than likely to be bad contacts, give it a shot of contact cleaner and a few insertions and extractions to wipe the contacts?

[mnementh]

   ...In other news, frozen pigs just flew out of hell… it looks like it actually works. Have ID’ed the probe sensor doesn’t work properly on one of the channels but that’s an easy fix. Might even work with a clean.

For 20 quid...? Def territory!

Not quite. Full clean and check out… Issues with channel switching. Looks like dirty switches and possibly a duff probe on my part. Hmm.

Huh...? Since when did the acquisition have to be fully functional to be a Jammy candidate?  IMO, if it lights up (and the light isn't FIRE!) for 20 quid that's a helluva deal. And look how that cleaned up... you can spend a lot of money making one work and never get it looking that good. 

mnem
*eagerly awaiting updates and nekkid 465 pr0n*

[Specmaster]

<snip>
Mmmmhmmm... so inconveniencing someone wealthy enough to own a car is criminal and prosecutable... but destroying lives and making it impossible for whole segments of the population to house or feed themselves, much less own a car, is okay because it's monopoly corporations and politicians doing it, so is just business as usual.

Does cast a stark contrast on the concepts of High Crimes and Misdemeanors vs The Golden Rule, doesn't it? 

EDIT:   That actually is even more perverse than I originally thought. Consider this all-too-possible scenario:
Entitled dickbag parks in a handicapped spot repeatedly; often enough that someone who actually has the permit notices. Said victim calls the cops and lets the air out of his tires so he can't get away before they arrive. At worst dickbag receives a ticket he can probably get out of if he hires a lawyer; handicapped victim actually faces criminal prosecution and jail time.   

mnem
we are fucking doomed.

That's about it, it's like, at least in the UK, it is not illegal for someone to park their car on your driveway, but it is illegal for you to remove it or damage it in any way 

[mnementh]

I broke my half style +4.0 market glasses and new ones are full sized with different type of lenses where only center is the real zoom.
Why I see sort of diminished things with those glasses? I can see closer with them but things are smaller and sort of unreal.
Is that a focal point or some brain thingy?

My experience with drug-store readers is that unless you pay the bux for name-brand, as often as not the magnification numbers are literally pulled out of someone's arse. Also quality is very hit-or-miss; lens clarity and refractive distortion can be horrifyingly bad on the Chinesium lenses.

It's a good thing I only use them for working at the bench; if I needed them for reading or the computer, I'd be one headachy widdle dwagon.

mnem

[Specmaster]

Ok on way back from hamfest now.

That absolute turd arrived at 08:30 and emptied it again 

Did manage to grab a manky tek 465, a solartron 7150, some 10 turn pots, TO18 heat sinks and a book to sell. And I still have change from £25 

Is the turd a dealer?

Yes. Same one I mentioned to you last time. He waltzed off with a pile of kit and left the trash for everyone else. Turns up as a seller but doesn't set up, goes round and empties everything off and that's it.

There are no rules around this? In any case, if he's a known quantity and you can learn what vehicle he uses, it should be possible to run interference and stop him from getting there early, if you can organise a few people for joint action.

Do they just leave straight after, or do they eventually set up their stall? I guess the organisers shouldn't let them in early if they arrive with nothing to sell. 

David

Or of course, they could just make a rule that nobody buys/sells anything until the fest is officially open to the members and public, but that would scupper BD's plans as well 

[Vince]

COMPONENT SORTING

Yes... I thought I had sorted all my ICs, but I found some more in a drawer.

Among them a big, huge DIP24 package that read " 74HCT xxx "... I thought no way, how could it be so big..... so looked it up, a 74HCT154, and it's a 4 to 16 decoder. So well yes I guess you do need more than 20 pins to cram it in... still, you get used to logic chips being 14 or 16 pins, not a mega huge, ultra wide DIP 24....

Found another big DIP package, 28 pins, marked MAB8440, no idea what that was. Couldn't find a datasheet for it but found a few datasheets closely related.

Looks like it's an ancient, prehistoric 8 bit MCU, made by Philips, with I2C inside, but some documents make me believe that maybe it's based on an even more ancient processor, an 8048, which might have been made by Signetics, rather.  So me guesses that maybe Philips bought Signetics, evolved their old 8048 design a bit to add their obligatory I2C stuff in it, because well, Philips.

So looks like mine has 4KB of mask ROM, programmed at the factory. Also a whooping 128 bytes of RAM.

Found the datasheet for the CPU core of the 84XX , as well as the datasheet for the MAB8441 which apparently is the same as my 8440 but just with an 8 bit LED driver added to it. So could use that datasheet and just ignore the LED bits, I guess.

I wonder if there is a way to read the contents of the internal mask ROM.... can't be bothered to read all the details of the datasheets for now, too hot for that, and I prefer paper, hate reading on screens.
At the very least, I guess one can affirm that there must be SOMETHING in that ROM... or else they would not have packaged the die in that DIP package to begin with...
Maybe at the least, I could try to power it up, give it a clock signal with my sig gen, a reset pulse.... and see if comes back to life ? Maybe it will do something....