Test Equipment Anonymous (TEA) group therapy thread

[mansaxel]

Locally (10-15km away) some of the small Bee Keepers lost a total of over 60 hives due to one local Potato farmer doing the wrong thing.

Without bees we're fucked.

Anyone need bits for one and or want to do battle with the seller to ship it its a cheap parts donor maybe eBay auction: #184975440512 Hp 432A Analog Power Meter

I've got one, which of course was cheap, as it lacked cable and mount. I've been meaning to play with thermistors and try to build a mount. Not that I think I'll get even close to the original in performance, but studying the circuit makes it look possible to at least make it an experiment.

Does anyone have a source for the connector? The newer ones look like a Kleintuchel, but this is somewhere between that and Großtuchel.

Non-TEA: I've finally gotten around to put a new lamp "glass" in the kitchen exhaust fan. Had to play around a bit with cutting and parting Plexiglas and finally came up with a method that works on larger and smaller pieces: Score on both sides by Stanley knife, say 5 cuts in the same groove is enough. Then clamp against edge of table and break off. It is often useful to clamp the small piece and break off the larger one.

Now, combined with a new pair of LEDs in the E14 sockets, I can see what I cook again.

[Specmaster]

As a first step we could try to stop dumping 1.300.000.000 metric tons of food every year.

100% agree with that, thats where the APP I use helps, "To Good To Go" it only works on both Android and IOS phones and or tablets, download it from the App store today and start helping to save both the planet and your pocket by rescuing food that shops near to you would otherwise be throwing in the dustbin because of its sell by date is close.

I often use it to get bags of baked items from Gregg's the bakers, Costa Coffee, Pizza shops and country Bakers, but there are green grocers, supermarkets, cafés  etc on the app. It all depends on your location at the time, go on, try it out, what have you got to lose?

[bd139]

Nothing like a food bargain as well. You will find me regularly in Asda just before closing. Got me 500g 5% mince for today’s dinner yesterday for 20p.

[Cymaphore]

Without bees we're fucked.

Quite frequently I have to develop regulators and make them work properly, evaluate, diagnose, qualify, debug them, and so on.

You develop some gut feeling in doing that. After a couple of years, you begin to notice things even in parts of diagrams and the motion of numbers. That's quite helpful, especially in complex systems. It's not taking away the actual work of calculating and hard confirmation, but it helps to be quicker in finding root causes. I think many people here experience it similarly.

If I look at all the issues we have with our biosphere, all those small regulator systems that add up, watercycles, oceans, production and consumption of certain carbon-gases, rates of extinction, change of air streams and ice, change of land, change of surface color of the planet, change of the oceans, increasing reduction in forest areas, ...

All of those are small regulator systems. Each and every one of those has at least one significant problem more or less directly related to us.

When I look at all those graphs, numbers and the "big picture" and apply my "professional gut feeling"... So many signs of already runaway regulators. If it was my machine at work showing all those signs, I would probably press the red button and calmly leave the room.

[Cerebus]

Tip:  you can bake these packets in the oven to recharge (dry) them, to be used again or after a humid period.  Just not too hot to burn the paper packet.

105ºC for 24 hours, in an electric oven. The latter ought to be obvious but it took some years to dawn on me that drying things out in an oven that produces "water of combustion" is a little counter productive.

[Cerebus]

Don't piss off French farmers: 

That might be a little bit difficult, French farmers seem to be permanently pissed off. I think it must be a job requirement or somesuch. 

[ch_scr]

Thanks to Capt'n Bullshot, my fire for time difference measurements has been rekindled.
I present: a DMTD based soley on (select) "logic" devices. Well it's all 74 series at least. Design exploits hopefully as much of the "analog" behaviour these can give.
Unbuffered inverter (74VHCU04) in self biased configuration make an ac-coupled input stage that should have a wide input power range. XOR as mixers as per Capt'n Bullshots example.
"Single-Bit Dual-Supply Bus Transceiver" (74LVC1T45) to give the XOR a (hopefully) more graceful output from a independent stabilized rail.
For output comperators after the LPF: Schmitt trigger buffers (74AHC1G17). For the hell of it, didn't have another comperator handy and these jumped me in a moment of overconfidence.
At least that's my defence if they turn out as single point of major performance degradation.
Mostly star-power-point layout and ample decoupling and ferrite beads. Logic lines feature series termination to take the edge off. LPF includes a ferrite bead to reduce fast edges going through.
This either works or it doesn't  Place your bets if this is a good idea, and if it breaks: where? 

[bd139]

Here we go. Pile-o-stuff arrived. All packaged in one box. Everything was neatly taped up with masking tape so it was plug side out, wrapped in bubble wrap then placed in a correctly sized box full of polystyrene chips. I am impressed!



Haven't powered anything up yet as still working. Not sure how long I want to bring the solartron up for in case the mains filter explodes.

Both are labelled as ex DTEO (Defence Testing and Evaluation Organisation) and are MoD labelled and crow footed 

Edit: quick power up test:

1. Tek 475 has some sickness. Horizontal is only spanning half the display (hopefully not tube damage!), one cracked knob and one loose shaft. I will take it to bits later and work that out. Probably repairable.
2. 7150 plus appears to be working fine but will check out properly later in short controlled bursts so the mains filter doesn't have time to go up 

[Cerebus]

If it was my machine at work showing all those signs, I would probably press the red button and calmly leave the room.

Unfortunately, were you to follow that action in the grand scheme of things you'd find yourself with Elon Musk, Richard Branson, Jeff Bezos and a handful of their minions for company. Not an attractive proposition.  And by minions I don't mean nice little yellow folk like Kevin, Stuart and Bob.

[bd139]

Quick update on the 475. It was advertised and shown fully working and now does not - deflection is not occurring at all towards the right hand half of the tube. This suggests that either the wire has come off, there is tube damage, something is dislodged inside it or there's an amp issue somewhere.

Going to approach the seller first...

As advertised:



As tested:

[Specmaster]

Here we go. Pile-o-stuff arrived. All packaged in one box. Everything was neatly taped up with masking tape so it was plug side out, wrapped in bubble wrap then placed in a correctly sized box full of polystyrene chips. I am impressed!



Haven't powered anything up yet as still working. Not sure how long I want to bring the solartron up for in case the mains filter explodes.

Both are labelled as ex DTEO (Defence Testing and Evaluation Organisation) and are MoD labelled and crow footed 

Edit: quick power up test:

1. Tek 475 has some sickness. Horizontal is only spanning half the display (hopefully not tube damage!), one cracked knob and one loose shaft. I will take it to bits later and work that out. Probably repairable.
2. 7150 plus appears to be working fine but will check out properly later in short controlled bursts so the mains filter doesn't have time to go up 

Yay, I was correct, it did get properly packed and well wrapped in bubble wrap 

Good idea with the 7150plus, the bloody filter in that is a pipe bomb waiting to go off, also bloody expensive if you replace it like for like 

[Specmaster]

Here we go. Pile-o-stuff arrived. All packaged in one box. Everything was neatly taped up with masking tape so it was plug side out, wrapped in bubble wrap then placed in a correctly sized box full of polystyrene chips. I am impressed!



Haven't powered anything up yet as still working. Not sure how long I want to bring the solartron up for in case the mains filter explodes.

Both are labelled as ex DTEO (Defence Testing and Evaluation Organisation) and are MoD labelled and crow footed 

Edit: quick power up test:

1. Tek 475 has some sickness. Horizontal is only spanning half the display (hopefully not tube damage!), one cracked knob and one loose shaft. I will take it to bits later and work that out. Probably repairable.
2. 7150 plus appears to be working fine but will check out properly later in short controlled bursts so the mains filter doesn't have time to go up 

Yay, I was correct, it did get properly packed and well wrapped in bubble wrap 

Good idea with the 7150plus, the bloody filter in that is a pipe bomb waiting to go off, also bloody expensive if you replace it like for like 

Will you be replacing the input jacks for modern shrouded one's? The holes will need enlarging if you do and the red and green sockets will also the PCB to be trimed almost to the edge of the circuit traces on it, so care is required.

[Specmaster]

Quick update on the 475. It was advertised and shown fully working and now does not - deflection is not occurring at all towards the right hand half of the tube. This suggests that either the wire has come off, there is tube damage, something is dislodged inside it or there's an amp issue somewhere.

Going to approach the seller first...

As advertised:



As tested:

Is it on both channels? Asking because you tested it on channel 1, but as advertised it was channel 2?

[bd139]

Quick update.

Tek 475. Spoke to the seller who's response was basically "you're probably holding it wrong"  . So I thought fuck it and cracked it open and went through the usual diagnostic steps. Had a look and the horizontal deflection plate wire was resting on the chassis, probably from a knock. Have bent it away and it works now. Total fix time < 5 mins. Still got it  . The power supply looks a bit noisy so will need a recap by the looks. I will of course measure that first!

Good news is it's a VERY late one. Date coded 1982 and they were discontinued in 1983.

Solartron 7150 plus. I'm going for the original part from RS (£29). Job done properly. As for shrouded jacks, no I'm going to leave them. This is going to be used for low voltage electronics work with mostly pomona clip leads so I don't need mains protection. If I'm going to do anything mains the Fluke 87 or 25 will come out.

[med6753]

The 475: One of the horizontal deflection plate wires popped off.

Edit...posted same time you did. I called it.....deflection plate wire off. 

[Cymaphore]

If it was my machine at work showing all those signs, I would probably press the red button and calmly leave the room.

Unfortunately, were you to follow that action in the grand scheme of things you'd find yourself with Elon Musk, Richard Branson, Jeff Bezos and a handful of their minions for company. Not an attractive proposition.  And by minions I don't mean nice little yellow folk like Kevin, Stuart and Bob.

That's not a suitable approach for the grand scheme of things anyways. I think there is no easy way out. I don't have a solution. I try to do my part in not contributing to the problem as much as I can, but besides that I lost my hope about it. Everything else is outside of my control anyways, people have to make up their own mind.

I think photovoltaics is a great and important technology. But that doesn't put me into "Team Solar Roadways Delusionists United".

Concluding, that great action would be needed to even have a change of dealing with the consequences of our actions and what's happening to our planet doesn't put me into "Team Billionare Spacenuts".

[med6753]

bd, if re-cap is required on the 475 use this adapter kit. Sez it's for 465 but I think 475 is identical.

https://www.ebay.com/itm/273254508468?hash=item3f9f3ce7b4:g:vwsAAOSwMxRgeyzu

[bd139]

Thanks for the link. It's actually cheaper if I design my own and get it shipped from JLCPCB 

So I did a quick ripple check with DMM And the 110V has 12V RMS ripple on it. All the other rails are good. Culprit found 

[Vince]

BD do you mean JLCPCB can do round/circular boards ??
.. or any arbitrary shape  ? I suppose they charge through the roof for non-rectangular boards no ?
How do they price this service ? Requires a supplement I guess !

[bd139]

They cut any shapes AFAIK. Never tried!

[tggzzz]

Nothing like a food bargain as well. You will find me regularly in Asda just before closing. Got me 500g 5% mince for today’s dinner yesterday for 20p.

Looking for "yellow labels" has several advantges apart from cost:

• speed: fewer things to look at, fewer choices to make
• serendipity: you look at things you wouldn't normally see, maybe even liking them so much you buy them again

[med6753]

Thanks for the link. It's actually cheaper if I design my own and get it shipped from JLCPCB 

So I did a quick ripple check with DMM And the 110V has 12V RMS ripple on it. All the other rails are good. Culprit found 

OK, if you can that route go for it. If you recall I used those adapters when I re-capped a 465B a few years ago. Worked great. 



Yea, 12V RMS ripple on the 100VDC is NFG. 

[Specmaster]

Nothing like a food bargain as well. You will find me regularly in Asda just before closing. Got me 500g 5% mince for today’s dinner yesterday for 20p.

Looking for "yellow labels" has several advantges apart from cost:

• speed: fewer things to look at, fewer choices to make
• serendipity: you look at things you wouldn't normally see, maybe even liking them so much you buy them again

Thats much the same thing with that app as well, you get no guarantees as to what you will be given, apart the approx value is going to 3 to 4 times the price paid. On one occasion, I grabbed a bargain from Gregg's and was given 2 bags for the price of 1. Simply stick what you can't eat that day in the freezer, job done.

[tggzzz]

1. Tek 475 has some sickness. Horizontal is only spanning half the display (hopefully not tube damage!), one cracked knob and one loose shaft. I will take it to bits later and work that out. Probably repairable.
2. 7150 plus appears to be working fine but will check out properly later in short controlled bursts so the mains filter doesn't have time to go up 

1: can even be one lead has fallen off the CRT x deflection (EDIT: I see I'm all-knowing )
2: short = <<30s, I presume - based on my experience with a 2445b

[Robert763]

Went to a provincial hamfest today, the first one for years.

Lots of stuff that should be put in recycling waste bins, lots of beer bellies, too few masks, fortunately most stalls were outside.

Was about to look a brass and mahogany box with many an in resistors, but the bloke in front of me nabbed it. Got something else that I don't need, condition unknown. If it works I'll flip it, if not then it cost less than the petrol any way.

We've got one coming up.
I've  grabbed some bargains over the years.

One time I noticed a nice leather case, & thought "that might be useful!"------at $A4.00, what was there to lose?

The guy popped it open, & there was a Levell audio oscillator in there ---a non- functional one!

I took it home, & it just turned out to be the FOUR 276  9v batteries dead.

These are "unobtainium" in Oz, (always were, our 276P batteries had a phenolic plug, instead of the press stud connectors).
Some appropriate AA battery holders fixed that problem, & away it went.

It's still going strong, & I must say, for something that looks "El Cheapo", it "punches well above its weight" when it comes to both specs & usability.

Bugger all hamfest wise in this part of the country at the moment. The usual ones where I end up with half a car of stuff (easier for me than many  ) are postponed until 2022. The closest one is actually St Neots which is still a fair trek from me.

I should probably do that one and go for a walk somewhere around there in the afternoon.

I'll be at St Neots.
 Possibly selling, I haven't decided yet.  A lot depends on SWMBO coming to mind the stall while I look around.