Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

Well, while you Aussies and Brits are comparing weather notes it looks like the change has finally happen here about 2 weeks later than typical. The snow pack is finally all gone. For the next week day time temps are going to be +15 C with night time temps just below freezing. Migrant birds have finally started to arrive...again about 2 weeks later than normal. Most ponds and streams are now ice free but still no sign of the frogs/toads with their mating calls. That should happen this week. Crocus are blooming in sunny areas. Daffodils are sprouting.

I guess Spring is finally here. 

Yup. Heard the geese a-honkin' t'other morning... and my eyes are all puffy, and stuffy sinuses. Spring is definitely here. Time to start taking my Claritin again, and rotate the snowblower into the back shed/lawnmower out to the front shed...

But not time to put the wellies and sneaker-condoms away... yet.

mnem

[Robert763]

Worst rain I ever saw was in a dessert of all places. It was Jordan in 1996. We were driving a Discovery and the rain was so heavy you could not see anything. I was the passenger and had to open the door and kneel in the foot well looking down to see the edge of the road so we could pull over without droping off the elevated road.

[THDplusN_bad]

Yeah I know why. There's a 14Hz offset between the reference clocks. That doesn't answer which one is correct, so I'll probably buy a Bodnar GPSDO and use that as the primary reference i.e. the third counter which is GPS disciplined.

That is however moot because the Racal just blew up rather smellily (is that a word)? Looks like the failed ZTX550 before was because a tant on the LC pi filter on the hybrid DC line was going intermittent short. It just went total short and burned up the L 



I think I'm going to have to replace all the tants in this one as a precaution. There's about 30 in it.

Ah, I love the smell of burned tantalum caps in the morning! Not! You have my sympathy - I passionately hate it when those "tants" cause the damage they are known for.
Good luck with the replacement work. I have developed a habit to replace them with low-ESR electrolytics..

Cheers,

THDplusN_bad

[tggzzz]

Worst rain I ever saw was in a dessert of all places. It was Jordan in 1996. We were driving a Discovery and the rain was so heavy you could not see anything. I was the passenger and had to open the door and kneel in the foot well looking down to see the edge of the road so we could pull over without droping off the elevated road.

Worst cloud I was ever in (or more accurately underneath) was like that.

The only way you could tell whether you were moving or not was to touch the ground with your skistick and see whether your shoulder moved.
You couldn't see a 12in drop until your ski went over it.
I saw someone stop and then fall sideways until the only thing you could see was the bottom of her skis: she couldn't see the very large hole she had skiied into.

Strangely, poles marking the edge of the piste were visible 100m away.

[mnementh]

Urrrk.

Testing revealed no continuity between any of the 4 major metal chassis components of my new PC case, even though they are in principle connected. None. Nada. Zilch. Also true of the 2nd chassis, still waiting in the box to go back to Amazon.

Black may be beautiful, but black epoxy paint is a fuggin' bitch. 

mnem
 

[bd139]

Heads up: bikersnhs user on eBay listing a bunch of Heathkit stuff underpriced. Not interested myself.

[Specmaster]

Just received my new USB-A to Lightning charging leads for my iPad, plugged them in to my multi-way USB-A hub, wired back to a 10A meanwell 5V power supply, but still wont charge the iPad, but will charge my phones, desk lamps etc?

Grab my other multi-way chargers, 6 ports, 4 marked with "i" and 2 with "G", plug the iPad into any of the "i" marked ports, it charges, plug into either of the 2 "G" ports, nothing and yet any of the phones and desk lamps etc will work in any of the ports.

Looked up the details on Amazon for the 6 way charger with the "i" and "G" ports and I noticed this statement, "High-speed charging rate.
All USB outputs are fit for kinds of USB powered device, can charge 6 devices with full speed at the same time. We design port5 and port6 for Android system based tablets, and port1–4 for iPad series tablets, but smartphones and other USB devices can ignore the code of USB outputs, they can be charged via plugging in any one of these outputs."

So does the iPad and iPhone require all 4 cores of the charging lead to be connected to allow charging to take place but Android only require the 2 main power cores?

The charger in question is here https://www.amazon.com/universal-family-sized-supported-different-standards/dp/B00GN9B4N4

[bd139]

I suggest you watch and read this https://learn.adafruit.com/minty-boost/icharging

It’s quite complicated but you need to set the D- and D+ lines up properly with bias voltages.

[Robert763]

 Tektronix 545B with trolley an plug-ins for £20
Collection only from Stockport
www.ebay.co.uk/itm/Tektronix-545B-oscilloscope/333928788346?
I wish I had the room

[bd139]

That's scary cheap. I'm tempted to but that definitely wouldn't go in my car 

OCXO board so far ...



And no I can't be arsed to knock up the OCXO module in FreeCAD 



I'll stick this on github once it's done, tested and working.

[Cerebus]

Looks like the average week here 

Had to Wade through this the other week on a walk...

I used to occasionally drink at the Tide End Cottage, a pub in Ferry Road, Teddington. The road ends at Teddington Lock and floods so often at high tide that, if you're in the know and someone's driving you to the pub you get them to park at the top end of the road. More than once I've left that pub at closing time to find the cars of the unsuspecting bobbing in the tide. This how I know that a floating car in London will always have an A-Z pressed against the rear window once it's flooded.

[Specmaster]

I suggest you watch and read this https://learn.adafruit.com/minty-boost/icharging

It’s quite complicated but you need to set the D- and D+ lines up properly with bias voltages.

Are so that explains it, they must also have changed the code in the last IOS update as well because I have other lightning cables as well that did work before but now don't, in any USB-A port on any charger, but there is continuity between both ends.

[SilverSolder]

I suggest you watch and read this https://learn.adafruit.com/minty-boost/icharging

It’s quite complicated but you need to set the D- and D+ lines up properly with bias voltages.

Are so that explains it, they must also have changed the code in the last IOS update as well because I have other lightning cables as well that did work before but now don't, in any USB-A port on any charger, but there is continuity between both ends.

This kind of stuff is what keeps me away from Apple products in general -  they like their gardens walled at that place...

My wife is now so irritated at how hard it is to get data (e.g. movies that she records) from her iPad to her PC that she has asked for a Windows laptop for her birthday...

[Neomys Sapiens]

And then there's the "heed the signs thing" 

They need to put up a sign for that!

I'm confused an pissed at the same time..

I found a nice offer for a sensor from a seller in Finland on ebay.de.
Made a reasonable offer, seller made a still acceptable offer that I accepted.

I think every TEA person on Ebay.de has watched some of this sellers' wares. Thanks for sparing me the experience.
 

[tggzzz]

Looks like the average week here 

Had to Wade through this the other week on a walk...

I used to occasionally drink at the Tide End Cottage, a pub in Ferry Road, Teddington. The road ends at Teddington Lock and floods so often at high tide that, if you're in the know and someone's driving you to the pub you get them to park at the top end of the road. More than once I've left that pub at closing time to find the cars of the unsuspecting bobbing in the tide. This how I know that a floating car in London will always have an A-Z pressed against the rear window once it's flooded.

Not a problem here, except with tourists at Weston super Mud. Here the normal tidal range is over 14m - see 30th March https://www.windfinder.com/tide/Portishead

Severe ones are at least a metre more, and the river flows backwards over lock gates. At such times I certainly wouldn't leave my car in the underround carpark by the harbour, since flooding that will be the last line of defence before the city floods!

[Neomys Sapiens]

A bit shabby looking, but at 40€ definitely worth a try - even as it is from Denmark.
A Danbridge DR6 resistance decade, which at 0.1% would be mid-range in precision if it works and I decide to keep it. Well, I'll give it a scrub and see how it turns out.

[mnementh]

I suggest you watch and read this https://learn.adafruit.com/minty-boost/icharging

It’s quite complicated but you need to set the D- and D+ lines up properly with bias voltages.

Are so that explains it, they must also have changed the code in the last IOS update as well because I have other lightning cables as well that did work before but now don't, in any USB-A port on any charger, but there is continuity between both ends.

It's not just Apple being dicks; it's also aboot the "cheap shite makers" and the eternal battle to stop stupid consumers from buying a POS charger with no short-circuit protection and blaming Apple when it sets their iPud on fire, or burning their junk off with the iPwn in their pocket after voltage spikes from the clone-of-a-clone regulator IC shits and short-circuits the charging chip in the iPwn and... you guessed it... blaming Apple.

Android devices also use the USB-C Power-Negotiation scheme, and they have actually used a variant of it it since long before the transition from Micro-USB to USB-C. This scheme is similar to that used by fApple, tho not with a chip in the cable. As mad as I am aboot my daughter's iPud, bottom line is a shitty supposedly "Apple Certified" multi-outlet charger is what killed it, and nearly killed her Amazon Fire tablet as well. The short-circuit protection was not adequate, and it melted multiple cables before I discovered it.

That's a fault in the charger's design, not the fault of Apple for trying to keep me from plugging my Apple device into cheap-shite chargers.

I've gone back to all the original chargers that came with her iPud and our tablets... and shockingly, no more melted cables and so far, (knock on wood) no killed iPuds or Tablets.

mnem
 

 

[Mr. Scram]

You know how you inevitably find stuff right after needing it? I'm currently working on a project and needed kit I've been unable to locate for two years, despite looking for it. I ordered new ones last week and they arrived yesterday. TODAY I find all the stuff I've been looking for. That little escapade cost me nearly 50 quid and in this case doubles aren't very useful. Unwrapped everything too so no sending it back either. I suppose the good news is that the project is back on!

[Mr. Scram]

It's not just Apple being dicks; it's also aboot the "cheap shite makers" and the eternal battle to stop stupid consumers from buying a POS charger with no short-circuit protection and blaming Apple when it sets their iPud on fire, or burning their junk off with the iPwn in their pocket after voltage spikes from the clone-of-a-clone regulator IC shits and short-circuits the charging chip in the iPwnand... you guessed it... blaming Apple.

Android devices also use the USB-C Power-Negotiation scheme, and they have actually used a variant of it it since long before the transition from Micro-USB to USB-C. This scheme is similar to that used by fApple, tho not with a chip in the cable. As mad as I am aboot my daughter's iPud, bottom line is a shitty supposedly "Apple Certified" multi-outlet charger is what killed it, and nearly killed her Amazon Fire tablet as well. The short-circuit protection was not adequate, and it melted multiple cables before I discovered it.

That's a fault in the charger's design, not the fault of Apple for trying to keep me from plugging my Apple device into cheap-shite chargers.

I've gone back to all the original chargers that came with her iPud and our tablets... and shockingly, no more melted cables and so far, (knock on wood) no killed iPuds or Tablets.

mnem
 

The "protecting the consumer" argument is blatant bullshit. They make plenty of choices in their hardware which would mitigate user error and cost essentially nothing, but which are omitted or intentionally circumvented. They're protecting their walled garden and wallet.

[Neomys Sapiens]

A LOT cheaper  It's basically a 1Mb/s transmission loss tester for 78R balanced screened network cables. It a current model and a new one from Ultra Electronis will cost about £20,000  well worth 99p 
https://www.ultra-pcs.com/air/ground-test-equipment/databus-network-analyser/

Jammy git!

[mansaxel]

OCXO board so far ...

I've hesitantly put a 10-pack of these in my shopping cart, but happened to read this little cautionary tale, so now am firing up KiCAD and misinterpreting the LMR33630 datasheet (TI says they'll rather sell me those, and they're cheaper too). If I heed the datasheet instructions on LC filtering and de-rippeling, I'll have a bunch of supplies from my 24V battery bank, and won't have to rely on the UPS for all smallish things like Rπ and ATA boxes. And, most importantly, the media converter / CPE for the Internet connection...

The regulator is in JLCPCB "extended" list, so am contemplating letting them do the SMT part of the project.

[mansaxel]

This how I know that a floating car in London will always have an A-Z pressed against the rear window once it's flooded.

What's an "A-Z"? The Authorities saying "Needs to pass MOT before driven on roads"? 

[mnementh]

ACCCCKKK! Phony LM2596 modules... 99% likely full of fire; even worse than a dwagon's belly! Run away... RUN AWAYYYY!!!

The little D-SUN mp1584en buck modules are still awesome, tho. 

mnem

[bd139]

Yeah watch out for anything claiming to be genuine parts from China. I’d rather have Chinese brand parts than fake western brand parts...

And now for something completely different. Racal 9917 sorted. Decided to look in the junk box and found enough parts to fix it for £0.

Subbed tants out for 4.7u low esr electrolytics, used 10uH RFC and a standard 100n X7R MLCC. No fire now.

[mansaxel]

ACCCCKKK! Phony LM2596 modules... 99% likely full of fire; even worse than a dwagon's belly! Run away... RUN AWAYYYY!!!

I suspected as much. So, that's why I'm going to build my own. I think. (the tale of what you need to do to them to make'm work sez that the switching frequency is like 1/3 of advertised; very fishy.)