Test Equipment Anonymous (TEA) group therapy thread

[bd139]

Hahaha sorry. I’ll keep an eye out here for cheap SP hand pieces.

I’ve got this on the watch list at the moment. Someone else please outbid me 

https://www.ebay.co.uk/itm/254733136183

[med6753]

And now for my original reason for logging in tonight:

Does anyone know what a fair price is for a used working Fluke 8060A multimeter?
I might be able to get one locally if I am lucky.
I want *need* more multimeters, handheld or bench.
(to be honest, I should at least get some proper leads for the few I already have before getting more)

The recent inexpensive Fluke 27's available in the US were too expensive when shipping and crossing the border was factored in.

I paid US$70 which probably is a bit much, but it works and the display is pristine. Add GSP and the pain is obvious.

Still looking into an Israeli 27, because some of them come with the HV probe.

In reality, I should care for my bank account and wait for the Gossen unit I did buy last week. 

I’ve never seen anything remotely worth paying the massively inflated prices for, most items from Israel look like they’ve been dragged through a swamp first.

25s are safe for use in an explosive atmosphere; I expect 27s are the same.

A swamp in Israel?

Perhaps he meant a salt swamp?    Sometimes good deals can be had from Israel. The replacement CCD hybrid modules for the 2430 came from one of those sellers. And considering that they sent me 2 of them for the advertised price of one and no additional desert sand included made me a happy camper. 

[Robert763]

Hahaha sorry. I’ll keep an eye out here for cheap SP hand pieces.

I’ve got this on the watch list at the moment. Someone else please outbid me 

https://www.ebay.co.uk/itm/254733136183

I'm already watching it but not going to outbid you

[med6753]

Hahaha sorry. I’ll keep an eye out here for cheap SP hand pieces.

I’ve got this on the watch list at the moment. Someone else please outbid me 

https://www.ebay.co.uk/itm/254733136183

I'm already watching it but not going to outbid you

Doesn't ship to USA.

[Specmaster]

Hahaha sorry. I’ll keep an eye out here for cheap SP hand pieces.

I’ve got this on the watch list at the moment. Someone else please outbid me 

https://www.ebay.co.uk/itm/254733136183

Sorry, no can do, go on you know you want it 

[bd139]

Zen Internet + OpenReach I am impressed.

Yesterday - 20 pair trunk cut. Reported at 10:30



Issue resolved this morning at 11:45  .

Hats off - they really did a damn good job.

[BU508A]

And here is something for the laughs. Electronics are involved as well.

[Fungus]

Still looking into an Israeli 27, because some of them come with the HV probe.

Mine came from the USA with the HV probe (ex-army - had a US army calibration sticker on it and looks like regular calibration was the only use it ever got).

[Fungus]

Does anyone know what a fair price is for a used working Fluke 8060A multimeter?
I might be able to get one locally if I am lucky.

I paid US$70 which probably is a bit much

Nah, that sounds about right.

[Saskia]

just made arrangements to pick up another 24 boxes of electronics parts ...

[med6753]

Zen Internet + OpenReach I am impressed.

Yesterday - 20 pair trunk cut. Reported at 10:30



Issue resolved this morning at 11:45  .

Hats off - they really did a damn good job.

Not just your line but a trunk line? How the hell did they do that? Were they blind? 

[bd139]

I think they had one eyebrow between the three of them.  That’s all I’m saying.

[BU508A]

I think they had one eyebrow between the three of them.  That’s all I’m saying.

This is a sure sign that Werewolfes were involved.   

[mnementh]

I'll see if I have any of those Tartan boxes in my toolbox. 

Naahhh... not overheating. This thing is all MOSFET; virtually no heat generated at idle. It has 2 40mm fans in LO-HI compressor mode (one high volume fan direct into a high velocity fan for higher total static pressure) to get lots of cooling in a small package. Their minimum RPM is based on the idle requirements of a multi-XEON or similar server; still a considerable amount of current draw. Any quieter fan would also be slower, and would do the same thing due to lower Tach output.

I've tried several recommended mods; even scabbed in a 7808 to power them (they're PWM controlled); but like I said... anything that successfully dropped RPM to a tolerable volume also made the PSU immediately either shut down after a few seconds or go into limp/POST-loop mode.



I'm currently working on a rear housing with a muffler built in; that's what this thing is. Just my 3DP is being all kinds of a dick to me right now. Guess it didn't like being moved. 

mnem
*knocks self unconscious with a compressor mallet*

I am guessing the PSU is monitoring the fan RPM and expects it to be above some minimum.  So when you drop the RPM, it goes below some threshold and the PSU goes into an error state.  The counter/divider idea was to trick the PSU into thinking the RPM is in the proper range, even though the actual RPM is less.

Could you use a Signal Generator to test that theory?  Disconnect the fan RPM line and feed a generated signal into the RPM monitor, and then you can take over control of the fan.

Mostly, it is about the enclosure being two sheets of metal lower than 1.75". In those 42mm you simply can't put a horizontal-flow fan that pushes enough air to cool the PSU without revving it. 

Additional constraints come into play in the intended application, where you need to pull air in one end, and push it out the other, and you will have another unit on top, another below, and another to one side. The supplies will typically be placed in pairs for A/B supply, into 1HE computers stacked 40 to a bay frame, so there is really no alternative to create a pretty narrow high-speed jet of cooling air.

I've experienced this exact supply in a parallel super computer consisting of 442 compute nodes in 12 rack cabinets. The heat load when the moron HVAC engineer shut the cooling off to do something that did not require shutting the cooling off was impressive. Temperature rise rate more than 1° science-degree per minute, starting at 24°...

I was going to write a whole long diatribe about the role of failure in design... but this is the nuts/bolts of it. I spent some time futzing around with a PWM dev board trying to trick the thing; it appears the POST includes a test loop where it ramps up the RPM and monitors it to make sure it "sees" the fan. There is an I²C bus connection at the pin header, which indicates to me that the server can modify fan speed to some extent in software as well; not sure if that includes revving down as well as up. A fixed signal will not work. A divider might... but it monitors two fans at the same time which operate at different RPM. It was at that point I stopped to re-evaluate my engineering scope and realized that the RPM isn't the problem; the noise at idle is. If it ramps up under load, it NEEDS to... just like my DPS-1200s.

I'd stick a 8 pin PIC in the circuit. measure the generated fand voltage / PWM and generate correct RPM to keep the control circuit happy. You could also use it to actually switch the fans to high speed when you need too. one of the 8 or 14 pin PICs with internal clock is more than adequate, no support components required.

That's great if I really wanted to spend a week polishing my programming skillz to develop a hindbrain for the thing. Hello, my name is mnem, and my Kung-Fu is weak. Have we met...?

This is why I decided to attempt a mechanical noise-abatement solution that allows the PSU to operate as intended rather than trying to trick the thing into thinking it's still shoved up a Dell server's arse.
 
mnem

[mnementh]

Obviously the halo was 'shopped into that pic... 

mnem
 

Well, they say beauty is in the eye of the beholder. Conclusion: Lady Cop must have been the photographer of that picture 

Beauty...? What does THAT have to do with anything in that picture...?  We were talking aboot the errant halo that somehow appears over your head, of all places.

mnem

[med6753]

I think they had one eyebrow between the three of them.  That’s all I’m saying.

Not quite sure what that means but I'll run it. 

And what the hell was a telephone trunk line doing in a tree anyway? We use telephone POLES over here. 

[med6753]

Obviously the halo was 'shopped into that pic... 

mnem
 

Well, they say beauty is in the eye of the beholder. Conclusion: Lady Cop must have been the photographer of that picture 

Beauty...? What does THAT have to do with anything in that picture...?  We were talking aboot the errant halo that somehow appears over your head, of all places.

mnem

Mae West is my hero. She didn't give a shit what anyone thought and if she wanted something she was going after it. 

[mnementh]

Hahaha sorry. I’ll keep an eye out here for cheap SP hand pieces.

I’ve got this on the watch list at the moment. Someone else please outbid me 

https://www.ebay.co.uk/itm/254733136183

Sonuvacrap! With tweezers and both stands! If they shipped here, I'd be tempted... you won't regret it.

mnem
 

[bd139]

I think they had one eyebrow between the three of them.  That’s all I’m saying.

Not quite sure what that means but I'll run it. 

And what the hell was a telephone trunk line doing in a tree anyway? We use telephone POLES over here. 

The single eyebrow here signifies inbreeding and low intelligence. These guys were so stupid they had one eyebrow between them.

As for poles we do as well here. But not on my place. The issue is that the cable runs along the front of the building and down the side then under the ground to the cable conduits under the pavement (sidewalk). Some stupid fucker planted a fig tree next to where the cables emerge and was told to remove it because it was damaging the foundations. So he hired the lowest bidder to do it who immediately cut the cable in half because dumbasses. 

Karma has been served though because the trunk cable that runs from the building to the street had to be replaced briefly replaced so they had to dig up half his garden and the rest is covered in mud and footprints 

[mnementh]

"Only two things are infinite; the universe and human stupidity. And I'm not sure about the former..." Albert Einstein

mnem
 

[BU508A]

The single eyebrow here signifies inbreeding and low intelligence. These guys were so stupid they had one eyebrow between them.

Hmmm...

[med6753]

I think they had one eyebrow between the three of them.  That’s all I’m saying.

Not quite sure what that means but I'll run it. 

And what the hell was a telephone trunk line doing in a tree anyway? We use telephone POLES over here. 

The single eyebrow here signifies inbreeding and low intelligence. These guys were so stupid they had one eyebrow between them.

As for poles we do as well here. But not on my place. The issue is that the cable runs along the front of the building and down the side then under the ground to the cable conduits under the pavement (sidewalk). Some stupid fucker planted a fig tree next to where the cables emerge and was told to remove it because it was damaging the foundations. So he hired the lowest bidder to do it who immediately cut the cable in half because dumbasses. 

Karma has been served though because the trunk cable that runs from the building to the street had to be replaced briefly replaced so they had to dig up half his garden and the rest is covered in mud and footprints 

Oh OK...over here someone with a unibrow is to be regarded with suspicion. 

Edit....or is single eyebrow and unibrow the same thing?

[bd139]

Yep.

[SilverSolder]

Obviously the halo was 'shopped into that pic... 

mnem
 

Well, they say beauty is in the eye of the beholder. Conclusion: Lady Cop must have been the photographer of that picture 

Beauty...? What does THAT have to do with anything in that picture...?  We were talking aboot the errant halo that somehow appears over your head, of all places.

mnem

Mae West is my hero. She didn't give a shit what anyone thought and if she wanted something she was going after it. 

"Goodness has nothing to do with it, dearie!"  -  classic! 

[Saskia]

Metcal PS800 any good ?