Test Equipment Anonymous (TEA) group therapy thread

[med6753]

"That's good... you've taken your first step into a larger world. One full of cheap Chinese electronic gadgets for a pittance all over your bench, delivered in no time via Amazon Prime..."

mnem
 

Desperate times call for desperate measures. But it's not my first rodeo. I do have a Chinese frequency counter, function generator, and bench DMM. 

[GreyWoolfe]

The real question is "Who is EEVBlog's token sane person?"

Mrs EEVblog.

Sure about that?  She did marry Dave after all.  Mrs. GreyWoolfe loves to keep reminding me how 'special' I am.  I keep reminding her that she was the one who married me.

That perspective did occur to me.... 

.... but if I remember correctly, when Dave moved out of the garage, she made it clear the lab would never be allowed back.  I call that a sane action.

That is also not a worry here.  All my toys sit on a workbench in my dedicated home office as I am a remote field tech working from home.  She had a say in paint color (medium grey with black trim and outlets/covers and she had some good suggestions as far as layout of workbench and desks but that is as far as it goes.  The space is truly my domain.  Garage is also mostly mine with 30 gal compressor, 61" rolling tool chest, floor drill press, table saw, miter saw, work table with 6" vise and 6" bench grinder and another work table with another non sliding miter saw and a B&D mini workmate with everything on wheels to move out into workspace and then back against the wall.  She can't say much out there either as she is a serious enabler, making sure I have what I need for her projects.  My work isn't in Med's league for visual esthetics but they get the job done for her.

[GreyWoolfe]

The real question is "Who is EEVBlog's token sane person?"

Mrs EEVblog.

Sure about that?  She did marry Dave after all.  Mrs. GreyWoolfe loves to keep reminding me how 'special' I am.  I keep reminding her that she was the one who married me.

DANGER WILL ROBINSON, DANGER!!!

Do not approach the topic of sanity and marriage; it is a black hole and the event horizon is radioactive! ABORT! ABORT! ABORT!!!

mnem
I know my wife is insane for marrying me; but as I am the beneficiary of said madness, I do NOT bring it to her attention lest she finally come to her senses...

She is fully aware of her insanity, she is the one who chased me down until I married her.  We know each other for 20 years, married for 16.  If she hasn't come to her senses by now, there is little chance she will.  She is my 2nd and I am her 3rd, she says she won't get rid of me as she is too old to train up a new one.  I, too, am a beneficiary but I give it back equally to keep the books in balance.

[Specmaster]

I'm not aware of Avo ever releasing one in a yellow colour, all the ones I've seen have been black. So is this yellow one an official colour they did for certain customers, or has someone at some point in its life painted it like that?

It looks like factory paint, it's too neat for the kind of customer modification done because someone in health and safety says "All XYZ equipment must be painted safety yellow". Safety yellow as a mandatory colour for certain classes of equipment is common in some industries, so it wouldn't be unlikely that it was a standard or special order factory option.

That was my thinking as, if so then it adds to the value I think as I have never seen a yellow one and if it cleans up nicely I think I'll keep it in that case rather than the spare black one I have. Hopefully when it arrives there will be other clues, maybe even a sticker that gives details as to where it came from?

Looks hand painted to me. A bit patchy for a factory job.

I thought that as well, but then I thought it could well be dirt of the users hands after seeing just how dirty some people manage to get their Flukes which are yellow as well. Won't have to wait too long to receive it and then we shall see if the "dirt" is indeed dirt or not.

[ch_scr]

Ok as promised, here are the photos of the calculator, it is one of the few that provides direct access to some engineering terms, T,G,M,u,m,k,f,p & n etc. The holy grail of course would be the Casio fx-61 with its dedicated electrical functions, but they are serious money.

I have multiple of the newer casios. The function / used price balance is golden on the "Casio FX 9860G". Downside is they are a bit bigger. The dedicated function keys for "T,G,M,u,m,k,f,p & n etc." are gone, but can be had if must in an sub-menu. IMHO it's the right decision and they have one dedicated button for the '10 to the power of' (aka EXP) and you just enter the exponent as +-3,6,9,12 etc. But take note that much of the buttons are close. The upside of the newer graphical interface is the option to enter the formula as written down, a lot less confusing and as such harder to make errors on. The graphical display also allows to have a nice scrollable history. I got multiple for ~25€. The display on the FX9860G is unlighted, and one of the best reflectice lcd I have ever seen. The newer models have transflective that are nice but not as good as this. But I want to take note of one additional thing: they managed to continue the design philosophy and the menu structure is nicely evolved from the earlier ones so that an upgrade has minimal fuss for the user, 95% of what you learned and used to do works the same or close enough. I did an afterwork electronic public school for the last 4 years (last written exam was on friday), and have upgraded from 9850 (released 25 years ago) I had in "high school" and training ed. One classmates also upgraded to the 9860G (from a newer model but closer to the breed shown in your post) and commented that transition was easy.
Edit: also note it still has a dedicated shift option to enter "i", a feature I sorely missed on my 9850 where you had to get it from sub menu.

[AVGresponding]

Discord is up and (mostly) running

[mindcrime]

Apparently my reflow oven controller has become infected with GAS now as well, and has a message for you lot.



 

[beanflying]

After poking around in the bowels of this Type 547 for several hours I am totally convinced that the only alternative I have to tracking down the +100V issue is to purchase an external supply capable of 100VDC. There are just too many branches of the +100V bus scattered around in the scope and I'll risk damaging the internal +100V supply with "try this, and try that".

Got this one from Amazon. States it can source up to 120VDC/3A and can be current limited. Should have it by Wednesday. Yep, cheap Chinese and probably dodgy construction but it should be good enough for what I need.

We can compare their powerful cores later in the week than  I looked at this option too when I ordered mine the only deciding factor for me was the photos showed the guts/hacking potential for my Hot wire project better.

[DC1MC]

And now for something totally unexpected, remember when some while ago people were receiving mysterious small packages of seeds from Aliexpress that put the US TLAs in a nervous breakdown ?

Well, I've been hit as well, with a package of 10 Fake-o-trons from Ali, to my great confusion (spend 1/2 hour looking for who could have send it), the look very nice (observe the picture), sadly the basterds didn't bother to put anything in those packages, just a wire wit a resistance of 0.27 ohm that you can see in the potato macro picture .

So some seller got itself a nice "Bewertung" that his fakeotrons are the bees-knees and I've got 10 pieces of useless crap rare and hard to find devices, available for a reasonable cost to forum members  .

Did someone received something similar ?

 Cheers,
 DC1MC

[mnementh]

Looks like a garden-variety IC protector to me. These are essentially a low-voltage fuse made using semiconductor production methods for cost, in a tape-friendly package.

N15 should be ~0.6A, IIRC.

mnem

[med6753]

One of my 485's needed a slight compensation adjustment on 1MEG input on Channel 2. An excellent opportunity to use the Tek approved adjustment drivers as provided by mnem. Worked perfectly. 

The power supply from Amazon is out for delivery.  Yesterday it said Wednesday delivery. I'll do a show 'n tell when I get it. 

[DC1MC]

Looks like a garden-variety IC protector to me. These are essentially a low-voltage fuse made using semiconductor production methods for cost, in a tape-friendly package.

N15 should be ~0.6A, IIRC.

mnem

I would totally test this , is there any datasheet available ?

EDIT: Got a supplier:https://www.aliexpress.com/i/32952220278.html  - Double lung electronic
Boy this stuff is not cheap 

 Cheers,
 DC1MC

[Specmaster]

One of my 485's needed a slight compensation adjustment on 1MEG input on Channel 2. An excellent opportunity to use the Tek approved adjustment drivers as provided by mnem. Worked perfectly. 

The power supply from Amazon is out for delivery.  Yesterday it said Wednesday delivery. I'll do a show 'n tell when I get it. 

I guess you have been enabled by an enabler with that power supply then, I was enabled last night by ch-scr and awaiting the delivery yet another calculator on Thursday 

Oh well, I suppose you can never enough calculators, power supplies, scopes, meters, signal generators..and so it just rolls on, where will it stop? My guess is when we either run out of space or money, which ever happens first. 

[mnementh]

Looks like a garden-variety IC protector to me. These are essentially a low-voltage fuse made using semiconductor production methods for cost, in a tape-friendly package.

N15 should be ~0.6A, IIRC.

mnem

I would totally test this , is there any datasheet available ?

EDIT: Got a supplier:https://www.aliexpress.com/i/32952220278.html  - Double lung electronic
Boy this stuff is not cheap 

 Cheers,
 DC1MC

Ummm... yeah. GIYF.

https://www.google.com/search?client=firefox-b-d&q=ic+protector

https://www.ntepartsdirect.com/ENG/PRODUCTLIST/CIRCUIT_PROTECTION_IC_PROTECTORS

https://www.nteinc.com/specs/15000to15099/pdf/nte15005e.pdf

https://www.ntepartsdirect.com/ENG/PRODUCT/NTE15021E

https://mx-en.alliedelec.com/product/nte-electronics-inc-/nte15021e/70515155/]

https://www.donberg.ie/catalogue/passive_components/fuses/n15.html

Just a few clicks yielded all these results. Looks like your part is a 50V-600mA Type N IC protector. 

EDIT:

As for cost... that is going to probably be for two reasons:

1) Economies of Scale and buying small quantities

B) They know this is a fuse, so they know most people looking to buy it (aside from manufacturers doing purchase orders in qty 100K+) are buying to do repair. They always mark that shit up to what the market will bear and for the cost of keeping track of & making small packages.

mnem
Look! I contributed something useful today! 

[mnementh]

"That's good... you've taken your first step into a larger world. One full of cheap Chinese electronic gadgets for a pittance all over your bench, delivered in no time via Amazon Prime..."

mnem
 

Desperate times call for desperate measures. But it's not my first rodeo. I do have a Chinese frequency counter, function generator, and bench DMM.

I know... doesn't make it any less fun to rib you a little, Mr. Hollow State is Still King self-proclaimed resident caveman-type...

mnem
 

[ch_scr]

Question: How hot was it today?
Answer:

[mnementh]

On The Bench Today: Parrot AR Drone Brushless Motor

      

I picked this up from the Thrift because it was A) $20 $16 Canuckistan shekels with my coupon and 2) because I knew I had leftover batteries that it would run on. The drone itself is in near-mint condition; still has all the film over the vacu-molded plastic bits.

Initial flight found it would not lift off, but rather appeared to have one weak quadrant; after further testing by swapping motors and ESCs, I deduced that the culprit was this motor. Before I spend twice the purchase cost on a new motor, I decided to pop the motor open and look for anything wrong. 

Visual inspection revealed no burnt windings. With the rotor magnet out, I could test resistance/inductance of the windings; all 3 pairs measured the same at 0.6Ω/0.01mH, so probably not an electrical fault.

The one thing I did find was that the rotor is severely out of balance; maybe even a wee bit lopsided. given the apparent lack of use on this drone, it is entirely possible this was a manufacturing defect. So right now, I've added a thin layer of epoxy (and a bit of solder there) to the light side to balance it out a bit. While still a little heavy on the one side, definitely not as bad as before, and I've added all I dare lest it rub on the windings.

Now just waiting for it to cure so I can try another test flight.

mnem

[med6753]

Question: How hot was it today?
Answer:

This works much better. 

[Saskia]

Guess Tautech can continue polishing that bullet. Diverticulitis.
If this worsens I'll need to go to the emergency room.
Bloody Hell.
This is not the way I want to lose weight

[med6753]

Guess Tautech can continue polishing that bullet. Diverticulitis.
If this worsens I'll need to go to the emergency room.
Bloody Hell.
This is not the way I want to lose weight

Oh no. Get better! 

[mansaxel]

Guess Tautech can continue polishing that bullet. Diverticulitis.
If this worsens I'll need to go to the emergency room.
Bloody Hell.
This is not the way I want to lose weight

[ a quick google later ]

I fully agree. Not the way to diminish.

[med6753]

The power supply showed up and it works. Quick peak at the inside.




The game plan is to connect into the +100V supply and slowly bring it up just the +100V and monitor the current. The 6080 regulator tube is a dual triode with a maximum plate dissipation of 13 watts per plate. The triodes are connected in parallel so that would be 26 watts at 100V or 260ma. In order to connect into the +100V supply I had to isolate it. I pulled V677 and V664. I also floated R677 and R650. The external supply will be connected at C709C.

If the +100V comes up via the supply by itself with no issues then I'll power up the rest of the scope PSU and see what happens.

   

[Neomys Sapiens]

One of my 485's needed a slight compensation adjustment on 1MEG input on Channel 2. An excellent opportunity to use the Tek approved adjustment drivers as provided by mnem. Worked perfectly. 

The power supply from Amazon is out for delivery.  Yesterday it said Wednesday delivery. I'll do a show 'n tell when I get it. 

I like to see those alignment tools at work!

[Specmaster]

Question: How hot was it today?
Answer:

No decent fans for sale in the shops then?

I can recommend one of these box fans if you have them over there, 3 speeds, 12" blades and rotating grill which sends the air stream spiralling around the room so everyone get the benefit without the huge footprint that a oscillating fans does.

[mnementh]

On The Bench Today: Parrot AR Drone Brushless Motor   
      I picked this up from the Thrift because it was A) $20 $16 Canuckistan shekels with my coupon and 2) because I knew I had leftover batteries that it would run on. The drone itself is in near-mint condition; still has all the film over the vacu-molded plastic bits.

Initial flight found it would not lift off, but rather appeared to have one weak quadrant; after further testing by swapping motors and ESCs, I deduced that the culprit was this motor...

Ah-HAAAH!

I found the actual culprit while handling the guts of the motor during reassembly; the magnet core had come loose on the shaft. I should've thought to look for this failure mode; I've seen it before on the little brushed pager-vibrator motors we use in our Tiny Whoop FPV micro-quads, and they are constructed very similarly to this micro inrunner brushless. A little alcohol rinse, then LokTite on the shaft during reassembly and here's the magic!!!

These 1st/2nd gen Parrot Drones got an undeserved bum rap for many years; given the price at the time for a turnkey brushless-motor quadcopter with 720P FPV video built-in, Waypoint, SONAR and GPS capability, they actually offered a lot of bang for the buck. Too bad they were so far outstripped so quickly by the China-Direct invasion.

mnem