Test Equipment Anonymous (TEA) group therapy thread

[mansaxel]

I'll throw in a pack of Maalox and a bucket of Magenbitter![/b][/i]

Just got a text back from cousin Imogene... she's happy to oblige, as long as it's not Cointreau and as long as there's no Smurfs.

Magenbitter is just that, bitter. Cointreau is not. I've had memorable (or lack of) experiences with both.

When in Karlsruhe, I mostly slept and ate icecream from Lidl. Then I took a 320km/h (that is 200mph) train to Paris.

[mnementh]

mnem
*toddles off to grill some kielbasa and burgers*

[Neomys Sapiens]

What do you expect from a FG501 so cheap that you were willing to buy it for the module frame?
Well, that it works just fine, of course! 

seen doing a 98kHz sine
and a shifted square at 500kHz
as well as (more cleanly) at 5kHz.

Ok, the frequency vernier knob is broken. And I have yet to sweep and gate it.
Do I really doubt that it will work? No.
Low expectations are rewarded - by Tektronix!
 
edit: a good hour later, and both frequency and amplitude do not budge a bit. That's a keeper, I suppose.

[Cerebus]

A little TEA before bedtime.

So, I got that AC power supply/transformer enclosure finished; I'll post some tidy pictures another time, this is more a "traps for young players" post. How many people when picking out a transformer notice, and take note of, the bit of the specification that says "Temp rise"? If you don't pay attention it can bite you on the bottom. The Vigortronix 50VA transformer I used here has a "Temp Rise" specification of 42ºC, which means that at full output and a typical lab temperature of 23ºC it's going to get up to 65ºC. Yes, transformers can get quite a bit hotter than you might expect.

I generally reckon that 50ºC is "touch safe" for dry things. Now, mine is in a case so it's going to be touch safe because you can't touch it, but is the enclosure going to be touch safe? Is the enclosure going to get rid of enough heat? Better err on the side of caution and test it, we like to be thorough here at the Cerebus TEA Works and Catslave Market. So, 2 x 25Ω aluminium clad resistors, a hefty 0.4 K/W heatsink with integral fan to clamp them to (with a spot of mineral oil to ensure good thermal contact) and we're good to go. Transformers have long thermal constants, they can take hours to get up to their steady state temperature.

So this has been sitting here for a bit over two hours, dumping 50W into a 50Ω resistive load (so the transformers full rated 50VA), and has reached steady state. Here's what it looks like:



The resistors are at 70ºC, the heatsink 43ºC, and the enclosure 43.8ºC in an ambient 22.3ºC.

It's comforting that the theoretical 20ºC rise for the heatsink is 20.7ºC, probably attributable to a little extra heat gain from the 240V mains on a 230V transformer, combined with a little extra direct convective loss from the resistors.

So everything's safe and the transformer can't be too hot because it hasn't tripped its thermal fuses. I didn't for one moment expect that it even might, experience tells me this was going to be fine, but it's always a good idea to test your assumptions when you can't easily build a simple thermal model. I mean, where would you start with a transformer mostly relying on convection and radiation inside a Hammond 1590 box? Hardly easy things to calculate thermal resistances for. You could if you really had to, but sometimes "seat of the pants" is good enough.

Now I have to figure out if I can get an actual temperature for the transformer without extra holes to thread a thermocouple through. Worst comes to the worst I'll let it get it up to temp, whip the top off quickly and measure it quickly - I doubt that it'd drop more than 1 or 2 ºC in the interim. That's a problem for another day.

[Zucca]

Trying to understand how much energy my US home is burning

oh let me use those BTU units, here in USA maybe are useful....

A few minutes later the numbers in Free42 are funny.
Monkey face on me.

Let me google it better

The British thermal unit definition varies as follows:

    The British thermal unit (IT) (BTU) is equal to 1,055.05585262 joules
    The British thermal unit (ISO) (BTU) is equal to 1,055.056 joules
    The British thermal unit (th) (BTU) is equal to about 1,054.35026444 joules
    The British thermal unit (mean) (BTU) is equal to about 1,055.87 joules
    The British thermal unit (39 °F) (BTU) is equal to about 1,059.67 joules
    The British thermal unit (59 °F) (BTU) is equal to 1,054.804 joules
    The British thermal unit (60 °F) (BTU) is equal to about 1,054.68 joules
    The British thermal unit (63 °F) (BTU) is equal to about 1,054.6 joules

BTU does not exist for me, and it will never exist on my planet....

Holy shit

[Zucca]

First analysis:



Bloody AC

[cyclin_al]

EDIT:  Oh yes, the dog demonstrated that she can go on walks by herself by bending 9 AWG wires of a chain-link fence 

Daughter's dog is similar. He is as sharp as a tack and instantly finds tiny gaps in fencing, even in the pitch dark. The only explanation is that he is scent/noise following.

Sometimes he returns the way he departed. Other times he finds a different way back through 4 neighbour's gardens and along the road.

One of my favourite pictures of him is when he decided he didn't want to be left behind.

He's cute ... and tiny.  Let's just say that mine makes much much larger holes in the fence.  Okay, I need to go find a recent picture... that seems to be the rule around here.

EDIT:  This is tiny ... part of the FML last week was no internet service while trying to work from home.  I had to work hard to convince my ISP to deliver a replacement DSL modem, rather than me driving to another city to go pick it up.  Remember, the truck is in the shop at the moment.  The new modem has great performance according to my ISP.  Here is the definition of great performance:  1186 ms latency, 0.10 Mbps download and 0.58 Mbps upload.  I call that tiny. 

EDIT2:  Try using Teams on that ...  Unfortunately, it can get worse than Teams.  We just got Office 365 online at work.  In the new Outlook, it takes 37 seconds for the (cr)app to respond to a mouse click.  Now I realize just how many mouse clicks it takes to accomplish anything with MS software.  Each click is an agonizing decision.  The best performance I can now do is two days to get through my daily email... 

[Robert763]

A little TEA before bedtime.
<SNIP>

Now I have to figure out if I can get an actual temperature for the transformer without extra holes to thread a thermocouple through. Worst comes to the worst I'll let it get it up to temp, whip the top off quickly and measure it quickly - I doubt that it'd drop more than 1 or 2 ºC in the interim. That's a problem for another day.

Take the 4mm earth terminal out temporarily?

[capt bullshot]

EDIT:  This is tiny ... part of the FML last week was no internet service while trying to work from home.  I had to work hard to convince my ISP to deliver a replacement DSL modem, rather than me driving to another city to go pick it up.  Remember, the truck is in the shop at the moment.  The new modem has great performance according to my ISP.  Here is the definition of great performance:  1186 ms latency, 0.10 Mbps download and 0.58 Mbps upload.  I call that tiny. 

EDIT2:  Try using Teams on that ...  Unfortunately, it can get worse than Teams.  We just got Office 365 online at work.  In the new Outlook, it takes 37 seconds for the (cr)app to respond to a mouse click.  Now I realize just how many mouse clicks it takes to accomplish anything with MS software.  Each click is an agonizing decision.  The best performance I can now do is two days to get through my daily email... 

Interesting, here (TM) I've got faster internet access at home than in the office, this includes corporate VPN connection from home (internal company services are faster from home than in the office). Teams is way more responsive @home than @work. Maybe it's because I'm working at a small forgotten outpost of a large corporation

[Cerebus]

A little TEA before bedtime.
<SNIP>

Now I have to figure out if I can get an actual temperature for the transformer without extra holes to thread a thermocouple through. Worst comes to the worst I'll let it get it up to temp, whip the top off quickly and measure it quickly - I doubt that it'd drop more than 1 or 2 ºC in the interim. That's a problem for another day.

Take the 4mm earth terminal out temporarily?

Staring me in the face, literally staring me in the face, and I can't see it. D'ya know what's worse? Those 4mm terminals have little solder turrets with a hole the whole way through, and I was thinking last night that perhaps I'd left the one in the chassis earth socket free of solder - and so I tried pushing the thermocouple tip in there to see if it would thread through! Doh! 

[m k]

Was somebody missing some HP 437B stuff, govplanet has few in Texas.
It's constantly creating localized links so use the search.

From PP I could use #13.
Assuming it's a normal DOS based thing.

I missed the additional comment about PP. Assuming you mean the 1662AS, no it's not a DOS box. It runs custom firmware from FLASH ROM. The floppy disk drive is DS/DD (720k) and will format/write/read in LIF or DOS. Note that the more common HD (1.44M) disks don't work. I have a 1663A that came with grabbers and cost nothing.

I have some wrapped boxes of noname still possibly MF2DDs but custom OS is a bit of a roadblock.
With old DOS and underlaying computer one can do almost anything but custom OS is custom OS.
From PP pictures my guessed solution was h-sync and "press F1 to continue" stylish something.

Do you mean that the drive can't write on HD material?
You can make DD from HD by blocking that other corner hole.
Though drives had many, then unknown, switches and jumpers, maybe more info is now available.

You can control it by GPIB of course.
The drive (in mine at least) is a "proper" DS/DD. There are two issues:
The magnetic properies are different and a DD drive may not magetise the disk enough. This may not be immediately apparent.
The head and track widths are different which can cause all sorts of weird problems depending on sequences of formatting / reading / writing over / reading.
Summary:
HD disks may work but highly likey to be unreliable

I had something beyond GPIB in my mind, not exact but something.

It seems that I can't remember anything old about disk materials.
Only thing concerning DD crackers is that nonames were bad, but it was equally so with HDs also.
With floppies I remember one formatting thing, DD drive was fine with HD drive written stuff if formatting was made by DD drive, clearly at least a track width thing.
Around here disks were usually unformatted but that shouldn't be an issue, CoCom hardly has anything to do with it either.

BTW,
some PP stuff.
Signal generators and spectrum analyzers okay, but resistance calibrator, and then AC calibrator.
Must be a collector fight, there is still time though.
Then what's wrong with counters, everybody already have one?

[tggzzz]

EDIT:  Oh yes, the dog demonstrated that she can go on walks by herself by bending 9 AWG wires of a chain-link fence 

Daughter's dog is similar. He is as sharp as a tack and instantly finds tiny gaps in fencing, even in the pitch dark. The only explanation is that he is scent/noise following.

Sometimes he returns the way he departed. Other times he finds a different way back through 4 neighbour's gardens and along the road.

One of my favourite pictures of him is when he decided he didn't want to be left behind.

He's cute ... and tiny.  Let's just say that mine makes much much larger holes in the fence. 

Yeah. Presumed to be a Jack Russell crossed with a Dachsund, but with a Jack Russell's temperament.

He can fit through holes made by cats and foxes and similar; we think he uncovers them rather than makes them. We're not sure since he is lightening fast; I've clocked him at 24mph when chasing a ball on a football pitch. (Yes, I strapped a GPS receiver to his back )

Okay, I need to go find a recent picture... that seems to be the rule around here.

TBH I wasn't sure I wanted to post a picture of Charlie, and only showed the thumbnail. I did consider posting a picture of a well-known female human to the "Post a picture of a dog" thread.

[Robert763]

A little TEA before bedtime.
<SNIP>

Now I have to figure out if I can get an actual temperature for the transformer without extra holes to thread a thermocouple through. Worst comes to the worst I'll let it get it up to temp, whip the top off quickly and measure it quickly - I doubt that it'd drop more than 1 or 2 ºC in the interim. That's a problem for another day.

Take the 4mm earth terminal out temporarily?

Staring me in the face, literally staring me in the face, and I can't see it. D'ya know what's worse? Those 4mm terminals have little solder turrets with a hole the whole way through, and I was thinking last night that perhaps I'd left the one in the chassis earth socket free of solder - and so I tried pushing the thermocouple tip in there to see if it would thread through! Doh! 

It's always easier when you are standing back.....

[mnementh]

A little TEA before bedtime.

So, I got that AC power supply/transformer enclosure finished; I'll post some tidy pictures another time, this is more a "traps for young players" post...

   The resistors are at 70ºC, the heatsink 43ºC, and the enclosure 43.8ºC in an ambient 22.3ºC...

Now I have to figure out if I can get an actual temperature for the transformer without extra holes to thread a thermocouple through. Worst comes to the worst I'll let it get it up to temp, whip the top off quickly and measure it quickly - I doubt that it'd drop more than 1 or 2 ºC in the interim. That's a problem for another day.

The last PSU project I did used a toroidal transformer... as the case I had was Al extrusion, I used silicone thermal pads under the transformer to thermally couple the two, as the usual rubber pads had long ago gone AWOL.  It did seem to make a noticeable difference in the "to the touch" temperature, and you could definitely feel the heat transferring along the bottom.

In retrospect, it probably would have been a good idea to add a layer or two of Kapton tape top & bottom. I did use bolt & locknut deliberately tightened just enough to keep it from moving out of concern for missing rubber pads. 

mnem
 

[mnementh]

...The new modem has great performance according to my ISP.  Here is the definition of great performance:  1186 ms latency, 0.10 Mbps download and 0.58 Mbps upload.  I call that tiny. 

EDIT2:  Try using Teams on that ...  Unfortunately, it can get worse than Teams.  We just got Office 365 online at work.  In the new Outlook, it takes 37 seconds for the (cr)app to respond to a mouse click.  Now I realize just how many mouse clicks it takes to accomplish anything with MS software.  Each click is an agonizing decision.  The best performance I can now do is two days to get through my daily email... 

Turn phone on hotspot mode, at least long enuf to check your e...?

mnem
*survived a week of our only internet being my phone several times with all the moves recently*

[mnementh]

A little TEA before bedtime.
<SNIP>

Now I have to figure out if I can get an actual temperature for the transformer without extra holes to thread a thermocouple through. Worst comes to the worst I'll let it get it up to temp, whip the top off quickly and measure it quickly - I doubt that it'd drop more than 1 or 2 ºC in the interim. That's a problem for another day.

Take the 4mm earth terminal out temporarily?

Staring me in the face, literally staring me in the face, and I can't see it. D'ya know what's worse? Those 4mm terminals have little solder turrets with a hole the whole way through, and I was thinking last night that perhaps I'd left the one in the chassis earth socket free of solder - and so I tried pushing the thermocouple tip in there to see if it would thread through! Doh! 

In all honesty C... I assumed you were wibbling over the assache (and potential for scarring the face of the project) of dismantling that part of the box, not that you hadn't thought to do that. 

As they say... Hindsight is always 20/20...   

mnem

[mnementh]

Trying to understand how much energy my US home is burning   oh let me use those BTU units, here in USA maybe are useful....

A few minutes later the numbers in Free42 are funny.   Monkey face on me.

   BTU does not exist for me, and it will never exist on my planet....   Holy shit

ISTR reading that the reason we use BTU over here is because it more accurately reflects the energy consumption of central forced-air heat (much more common than other forms of heat) & AC, as opposed to steam/hot water radiators. Also that it more conveniently translates into airflow calculations necessary for ductwork and air-handler sizing.

mnem
*math-defective*

[BU508A]

One for mnem:



 

[TERRA Operative]

Ugh, I need to stay off Yahoo Auctions.....
Just scored a Tek P6015 HV scope probe for about equal to US$135

Didn't even really need it, but I got it on the way now.

[Robert763]

<SNIP>

BTW,
some PP stuff.
Signal generators and spectrum analyzers okay, but resistance calibrator, and then AC calibrator.
Must be a collector fight, there is still time though.
Then what's wrong with counters, everybody already have one?

Yes bit weird on pricing at PP. A HP3456A got £243 (plus fees and VAT) but a couple of Solartron 7060s only made £54 each.
A lot of last second bids so either automated or people don't realise it extends by 2 minutes if you bid in the last two minutes.

EDIT: Just noticed that a HP3438A (plastic case 1/2 rack 31/2 digit DMM) sold for £200 (£277 with commission and VAT, $377 US) WTF 

[mnementh]

One for mnem:      

   

https://joshuawright.net/slack-wyrm-050.html

mnem
};=)~~~~<

[med6753]

Ugh, I need to stay off Yahoo Auctions.....
Just scored a Tek P6015 HV scope probe for about equal to US$135

Didn't even really need it, but I got it on the way now.

With or without the dielectric fluid necessary to use it at full ratings? The freon based fluid is no longer available but according to TekWiki a silicone based fluid is now used. But they are mum as to what exactly that fluid is.     

[Cerebus]

Ugh, I need to stay off Yahoo Auctions.....
Just scored a Tek P6015 HV scope probe for about equal to US$135

Didn't even really need it, but I got it on the way now.

With or without the dielectric fluid necessary to use it at full ratings? The freon based fluid is no longer available but according to TekWiki a silicone based fluid is now used. But they are mum as to what exactly that fluid is.     

You can get PFPEs from Galden that would probably do the job, dielectric strength 400kV per inch.

https://www.solvay.com/en/brands/galden-pfpe/properties

[tggzzz]

<SNIP>

BTW,
some PP stuff.
Signal generators and spectrum analyzers okay, but resistance calibrator, and then AC calibrator.
Must be a collector fight, there is still time though.
Then what's wrong with counters, everybody already have one?

Yes bit weird on pricing at PP. A HP3456A got £243 (plus fees and VAT) but a couple of Solartron 7060s only made £54 each.
A lot of last second bids so either automated or people don't realise it extends by 2 minutes if you bid in the last two minutes.

EDIT: Just noticed that a HP3438A (plastic case 1/2 rack 31/2 digit DMM) sold for £200 (£277 with commission and VAT, $377 US) WTF 

HP3478A £250+15.5%+20%
HP85 similar (much less than previously)
8*Tinsley standard resistors £500+15.5%+20%

I like the last, since I have several

[m k]

Fluke 8520A for £19 wasn't very high price.
Though HP 3478A screen had numbers when Fluke was dark.

HP 3476x art deco price was decent, can't find a lot, and bundled with a scope, with issues though.

User "contrastled" won so many items that if not automated then at least an excel of some sort was needed, and maybe £10k.

Ice-Tea got something also.
(if TM503 is a leftover one day don't throw it away)

Overall very little average Joe winners, it seems.