Test Equipment Anonymous (TEA) group therapy thread

[AVGresponding]

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.

[bd139]

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.

[AVGresponding]

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.

[Vince]

Pffff.... why not just stick to the simple, tried and tested method : just shove a potato in the exhaust tip, engine won't start and zero damage to the car ! 

EDIT : on some cars the exhaust tip is hidden behind the bumper, which makes it much less convenient... crappy access. In this case AVG's method is recommended as an alternative. Deflating the 4 tires takes more time but access to the valves is good. So I wold suggest potatoe if the exhaust tip is visible / accessible, and if not, deflate all 4 tires.

[bd139]

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 

[AVGresponding]

Pffff.... why not just stick to the simple, tried and tested method : just shove a potato in the exhaust tip, engine won't start and zero damage to the car ! 

EDIT : on some cars the exhaust tip is hidden behind the bumper, which makes it much less convenient... crappy access. In this case AVG's method is recommended as an alternative. Deflating the 4 tires takes more time but access to the valves is good. So I wold suggest potatoe if the exhaust tip is visible / accessible, and if not, deflate all 4 tires.

There's nothing to stop you doing both!   

[AVGresponding]

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 

Tin whiskers/corroded legs in the driver transistors?

[bd139]

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 

Tin whiskers/corroded legs in the driver transistors?

Possible. I’ll trace it out later. The thing has row and column drivers and the DP is seen as a row which is controlled by the main ASIC. The decimal point does work in ohms which suggests something might be amiss upstream on DC volts auto ranging.

[AVGresponding]

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 

Tin whiskers/corroded legs in the driver transistors?

Possible. I’ll trace it out later. The thing has row and column drivers and the DP is seen as a row which is controlled by the main ASIC. The decimal point does work in ohms which suggests something might be amiss upstream on DC volts auto ranging.

Ah, bummer.

[med6753]

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 

Do you still need some parts for your 465B? The 465 that you grabbed today may not have those same parts. And did you finally get that IC?

If you need something let me know.

Yeah the 465 today is useless for repairing this. I'm semi hoping it works as well  . I'm after the timebase ROM on the vertical board. I will PM you - any help appreciated!

OK, I'll wait for your PM.

[grizewald]

I'm amazed that Tek 465 actually works. Score!

[med6753]

I'm amazed that Tek 465 actually works. Score!

Not too worry. After a few power cycles at least one tant will flip the bird with copious amounts of magic smoke. 

[factory]

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

[factory]

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 

Could it be a bad connection? I had this with my Solartron 7075, it was working fine before I got it, when it arrived it would only display even numbers (original cal seals were intact), I reseated some connectors & have had no problems since.

David

[bd139]

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

He actually leaves around 10AM. Never sets up a stall. I will get his plate next time and start shit posting about it to event organisers.

[tggzzz]

Ok on way back from hamfest now.

I couldn't have gone; I was visited by a 1972 ice cream van full of ice cream It was equally full when it left, due to supply chain difficulties

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

Stop whining and copy him! If necessary, look in the left column of one of your posts.

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 

I thought "meh" until I saw the price.

Sounds like all the newly retired have bought the 465 they always hankered after, so market become softer. Or was it just "keep in garage not in house" manky?

What are you going to do with the 7150? I have a 7151 with cal until August 2020 that I ought to flog.

EDIT: I've now read more than your first tweet.

[bd139]

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 

Could it be a bad connection? I had this with my Solartron 7075, it was working fine before I got it, when it arrived it would only display even numbers (original cal seals were intact), I reseated some connectors & have had no problems since.

David

Possibly. Good idea. I’ll have a poke around it when I get a minute. The main ASIC is plessey so I bet something is broken inside it 

[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.

Top layer, left: the main analogue board.

Note the row of guaranteed dead Phillips electrolytics at the lower front of the board. I knew I would have to replace all of them as a matter of course. At the top left of the picture are the two selected 1N829 Zener diodes that provide the positive and negative reference voltages.

Top layer, right: the digital board.

The battery which powers the RAM with the calibration constants reads 3.6V. A classic 6800 CPU as the brains of the unit.
Both boards show date codes in the range of late 1986 to mid 1987, so this is a relatively new model, which is also evidenced by the lack of bodge wires anywhere. Under the heatsink is the Ferranti ZNA2035 A-D chip - made from pure unobtanium.
 
Once I'd extracted both boards from the case, there was evidence that the analogue board has previously been repaired as there were flux residues on the underside which hadn't been cleaned off.

Underside layer, left: GPIB interface and display control board.

Both boards with chips of the same vintage as the main boards on the other side.

Underside layer, right: the current, AC and ohms boards.

So the machine has the full set of boards. No obvious problems like discoloured tants on any of them, which is a relief.

But of course, it's rare to find one of these meters in perfect working order and this one was no exception...

edit:images shrunk to 500 pixel previews - clickable for full size

[bd139]

Ok on way back from hamfest now.

I couldn't have gone; I was visited by a 1972 ice cream van full of ice cream It was equally full when it left, due to supply chain difficulties

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

Stop whining and copy him! If necessary, look in the left column of one of your posts.

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 

I thought "meh" until I saw the price.

Sounds like all the newly retired have bought the 465 they always hankered after, so market become softer. Or was it just "keep in garage not in house" manky?

What are you going to do with the 7150? I have a 7151 with cal until August 2020 that I ought to flog.

EDIT: I've now read more than your first tweet.

I should change the avatar away from Ferengi. The Ferengi antics are now relegated to covering the fuel costs. I will be keeping equipment where possible and using it for a few projects.

It’s a 7050 not a 7150 to be clear. Typo when I was sitting in the car. I will probably keep it if I can fix it as it smells of 70’s electronics and sort of has 5.5 digits.

[vk6zgo]

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?

I think he is a globetrotter!

[Cerebus]

I just missed a hp 3435A.
It was for sale on the "Amateur Radio Western Australia" Facebook Group, for local pickup across town, at $A25!!

(Attachment Link)

I console myself by saying "Maybe it didn't work!".

That's only about 14 shillings and 6d in old money!

Not $1.45,---$25.00

That's "£12/10/0", I'll have you know!---at least in Oz "old money"

No, it's about 14s/6d at the value of money when 14s/6d existed, not 72¹/₂p at current value.

[factory]

There is a option in ebay to disable combined shipping, whether the seller turned it on by accident, or intent, or it's the default option is another matter.

I've finally had some success with getting international shipping added to an item I really wanted, annoyingly ebay made it very difficult for them, as international was disabled by default, then when they had turned it on most countries were still excluded by default, thankfully after several messages back & too last night I was finally able to buy it.
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

Wow, ncie bit of kit !! 

Sure was well worth the Ebay trouble, you have been rewarded.

Looks really nice, no less than 6 digits DVM, impressed. Must be really super accurate and fancy inside.

I mean my Rochar Nixie DVM is quite nice I find, at 0.1% accuracy, yet it has only 4 digits. So your new toy with 2 more digits must have truly incredible specs then, much better than 0.1%.
Also, my Rochar has pots on the front panel to adjust zero offset, and full scale deviation... so not super stable. But yours doesn't have that despite it's, I presume, much better accuracy. So it must be really state of the art inside.

Waiting for the tear down pics now...

Does it have a printer output at the back ?

When do you think you might be receiving it ??  A couple weeks ?

It's 100000 count with 20% overrange (except 1kV range), full specs attached.

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


Usually around two to three weeks for US stuff ATM.

I look forward to seeing pics of the innards.  The outards (front panel at least) look very similar to the Fairchild 7000, but with an additional digit.  Wonder if there was any incestuousness going on betwixt the two companies



-Pat

I believe Systron & Fairchild (TE division) either merged, or one took over the other  , hence why they look quite similar. See this random picture borrowed from ePay.


Will take lots of pictures when it arrives.

David

[tggzzz]

Not too worry. After a few power cycles at least one tant will flip the bird with copious amounts of magic smoke. 

Not necessarily; I've discovered Fluke  515As have several 20V tant beads on an 18V PSU line. They are all still intact, in both my 515As.

I got my second 515A at a Newbury hamfest, and found it had a strange error: the 0->1V Vdc ranges were all about 9.995 times the specified value, and the µV range was completely cockeyed. But the 0-10Vdc, 100Vdc and Vac outputs were all pretty good.

Fluke was clearly channelling B&O 70s audio amps, since each output was routed through several multipole switches (S2-S12 below), ugh.  The schematic was clearly drawn by a Rubylith PCB engineer: each board had its components crammed onto a single schematic, with individual components placed wherever there was space - and not moved after placement.  Ugh again. Given the relevant part of the schematic below; see if you can figure out how the reference J11-pin8 reaches the output "HI" A1-J1 post for each of the settings of S2-S12:



So naturally I presumed it was a faulty switch somewhere. Oh no. That would have been as boring as soduku.

I turned out that a previous owner had switched a guard connection with an output low connection. Obvious innit.

Fix that, and it all tweaks up pretty well. All I have left to do is manufacture a replacement for a funky knob clearly inspired by DEC PDP-11s (no, not additive printing ), and repair the red plastic 4mm banana post.



Those tants: I'll leave the next owner with something to allow them to think they have improved it.

[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
 

[BU508A]

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