Test Equipment Anonymous (TEA) group therapy thread

[Neomys Sapiens]

regarding VFD replacements:

there is a very nice US company which does produce VFDs and other fine displays:

https://ieeinc.com/vacuum-fluorescent-displays

[BU508A]

Not so sure I'm going to order from this HVStuff.com outfit again. First, when I realized they were in China it didn't give me warm fuzzies. 2nd, I placed the order on December 22 and as of this morning it still hasn't shipped. Now I paid for "7 to 30 day international shipping" but to me that means it's gonna take that long to get here through the mail. But apparently means they will ship when they finally get around to it...like whenever. Funny, it didn't take "whenever" when they took my money. That was same day.

And then of course....will the parts be real or fakes?  (If I ever get them). 

If you need some more of those HV rectifier diodes, I can send you some. Just let me know.

[mnementh]

The "acetone slump" isn't quite that bad, usually less than 0.25mm. What can cause problems is that it rounds off all sharp corners and small details. For PLA you can get a similar effect using Ethyl Acetate, but beware, it's seriously nasty stuff and you should only use it outdoors if you want to survive the process!

McBryce.

I think we're talking about the same thing only in different ways; the problem is that proud areas will sometimes slump more than 250 microns, while flat and concave areas may slump less or worse, collect material slumped from other areas. It is a VERY temperamental process; it requires surviving a lot of FAIL! parts to develop the skill/feel for how big a chamber, how long, how warm, etc a given piece will need.

Of course, like all such processes, the more people do it, the larger the body of tutorial materials out there to draw from and minimize that learning curve.

I personally have very little personal experience due to the hazardous nature of Ethyl Acetate and the fact I already have enough health concerns; not interested in looking for new ones.

I still prefer PLA as it is so much more "family-space friendly" than ABS. However... acetone-polishing will probably be one of the driving forces once I do expand into ABS with my 3DP printing experience.

mnem
 

[mnementh]

   Cheap Tektronix 492 on ebay this morning (699$US).   https://www.ebay.com/itm/304287204898

Has option 1,2,3 (Preselector, Digital Storage, 100Hz Resolution Bandwidth) and look like it's working fine.

*wibble*

mnem
*starts looking around the basement for stuff to sell*

[McBryce]

The "acetone slump" isn't quite that bad, usually less than 0.25mm. What can cause problems is that it rounds off all sharp corners and small details. For PLA you can get a similar effect using Ethyl Acetate, but beware, it's seriously nasty stuff and you should only use it outdoors if you want to survive the process!

McBryce.

I think we're talking about the same thing only in different ways; the problem is that proud areas will sometimes slump more than 250 microns, while flat and concave areas may slump less or worse, collect material slumped from other areas. It is a VERY temperamental process; it requires surviving a lot of FAIL! parts to develop the skill/feel for how big a chamber, how long, how warm, etc a given piece will need.

Of course, like all such processes, the more people do it, the larger the body of tutorial materials out there to draw from and minimize that learning curve.

I personally have very little personal experience due to the hazardous nature of Ethyl Acetate and the fact I already have enough health concerns; not interested in looking for new ones.

I still prefer PLA as it is so much more "family-space friendly" than ABS. However... acetone-polishing will probably be one of the driving forces once I do expand into ABS with my 3DP printing experience.

mnem
 

I only use PLA for the same reasons. ABS vapours aren't something I want to be filling the family home with (not to mention the dreadful stench that comes with it)!

McBryce.

[med6753]

Not so sure I'm going to order from this HVStuff.com outfit again. First, when I realized they were in China it didn't give me warm fuzzies. 2nd, I placed the order on December 22 and as of this morning it still hasn't shipped. Now I paid for "7 to 30 day international shipping" but to me that means it's gonna take that long to get here through the mail. But apparently means they will ship when they finally get around to it...like whenever. Funny, it didn't take "whenever" when they took my money. That was same day.

And then of course....will the parts be real or fakes?  (If I ever get them). 

If you need some more of those HV rectifier diodes, I can send you some. Just let me know.

Thanks for the offer. I didn't order any additional diodes from them. Just the HV disc ceramic capacitors. But if I need the diodes I'll let you know.

[ch_scr]

The "acetone slump" isn't quite that bad, usually less than 0.25mm. What can cause problems is that it rounds off all sharp corners and small details. For PLA you can get a similar effect using Ethyl Acetate, but beware, it's seriously nasty stuff and you should only use it outdoors if you want to survive the process!

McBryce.

I think we're talking about the same thing only in different ways; the problem is that proud areas will sometimes slump more than 250 microns, while flat and concave areas may slump less or worse, collect material slumped from other areas. It is a VERY temperamental process; it requires surviving a lot of FAIL! parts to develop the skill/feel for how big a chamber, how long, how warm, etc a given piece will need.

Of course, like all such processes, the more people do it, the larger the body of tutorial materials out there to draw from and minimize that learning curve.

I personally have very little personal experience due to the hazardous nature of Ethyl Acetate and the fact I already have enough health concerns; not interested in looking for new ones.

I still prefer PLA as it is so much more "family-space friendly" than ABS. However... acetone-polishing will probably be one of the driving forces once I do expand into ABS with my 3DP printing experience.

mnem
 

I only use PLA for the same reasons. ABS vapours aren't something I want to be filling the family home with (not to mention the dreadful stench that comes with it)!

McBryce.

ABS has no "stench". Upon printing it emenates the odour of all three carcinogenic constituents at the same time 

[BU508A]

Today arrival:

10 ft of 4x 16AWG PTFE insulated and shielded wires with silver plating:

https://www.ebay.com/itm/274682605011



Useful for making low-EMF cables.
Man, those 10ft are heavy. 

[m k]

Tube noob wondering, sell or not?
(All Wave Oscillator)

[mnementh]

   https://kano.tech/us/original

On The Bench Today: Kano Touch LCD/Digitizer

So... before we left Tejas, I bought this kit for my son as a STEM stimulus project. Well, in the confusion of the move, it got packed away instead of packed up to go with us.  Sadly, where/how it got packed wasn't ideal; the box it was in wound up right in the middle of a stack and got more than a little crushed, then the kit box got crushed too... after who knows how long under pressure, the LCD made contact with the digitizer glass and this was the result.

At the time I got the thing, it was on blowout from a company liquidation; I paid $80 which I thought was fair reasonable for a full kit with Pi3B, 10" HD Touchscreen, wireless KB/touchpad and a fully realized portable power system/case. I figured the STEM-specific flavor of Debian that came with, while a bit simplistic (aimed at 6 and up), if he showed an actual interest in the coding and dev lessons it offered, we could get him into Raspbian or some more general OS. Of course now that the boy is back in school, his STEM-heavy coursework has him just chomping at the bit to build and use the thing, just as soon as he saw the box on my bench.

Well now they're a disco product (replaced by a entirely too dumbed-down model based on Win10) and crazy expensive; like over $150 for used, and one new in sealed box unit that went for $450 at Christmas.

As such, really not available at a price reasonable as "parts"; so I need to separate the digitizer from the bezel, then try to figure some way to relieve the pressure on the back of the LCD so it no longer contacts the glass. This is gonna be a 3-flagon move, I suspect. At least.

mnem
Y'all may now start making popcorn; this should make a good show... 

[mnementh]

   Tube noob wondering, sell or not?   (All Wave Oscillator)

It needs to be serviced, spit-and-polished, then put up on a shelf with at least two of its AVOmeter cousins.

mnem
Seriously; what other answer did you expect, asking that question in here?

[BU508A]

Seriously; what other answer did you expect, asking that question in here?

"Put a lamp on top of it."

 

[wolfy007]

Seriously; what other answer did you expect, asking that question in here?

"Put a lamp on top of it."

 

Noooo, dont even joke about it....   

[tggzzz]

Cheap Tektronix 492 on ebay this morning (699$US).

https://www.ebay.com/itm/304287204898



Has option 1,2,3 (Preselector, Digital Storage, 100Hz Resolution Bandwidth) and look like it's working fine.

If I didn't have one, I'd make an offer

[Martin Miranda]

  here we go again, took this puppy home, got it for a song. the owner does not know anything.
updates later, good night. 1:42 AM Wednesday, Philippines (GMT+8)

[Atomillo]

Hi!

Christmas arrived a bit late, but very happy with it!
From eBay, a HP34401A in mint condition which will become my main driver from now on. Since it was second hand, I expected the screen to be a bit faded, but this was not the case at all! It looks like new, and has great visibility from practically any angle with and without ambient light.

Also from eBay, a HP3455A voltmeter. This one did not have any guarantee, but seems to operate perfectly, and as shown passes it's self tests. There's however one thing that worries me: one can periodically hear what seems like three very quiet and faint beeps, which by hearing it in long integration time voltage measurements made me think that it happens when the multimeter is making a reading.

I think it sounds like a beeper and not a relay, but I can't find any mention of a beeper in the manual. I've taken apart the upper cover, but all the analog part, from where the sound seems to come, has another shield that I do not dare to open, and I also didn't see any beeper in the exposed part. Unfortunately, I have finals until 19 January so I do not have much time to dig deeper now but I would still like to know if this is something normal

Many thanks for all your help and a late happy holidays!

[AVGresponding]

Today arrival:

10 ft of 4x 16AWG PTFE insulated and shielded wires with silver plating:

https://www.ebay.com/itm/274682605011



Useful for making low-EMF cables.
Man, those 10ft are heavy. 

Sounds expensive...


RF gen update: Seller messaged today they are speaking to their supplier, and will update me within a day.

[BU508A]

Has anybody an idea, what this could be and where it is used?

This is an adhesive strip, about 30cm long and on one side there are two metallised strips of an unknown material.

[xrunner]

Are the two metallized strips really just one with another strip of adhesive? If so might be used for some RF shielding in certain areas of a chassis.

 

[Kosmic]

There's however one thing that worries me: one can periodically hear what seems like three very quiet and faint beeps, which by hearing it in long integration time voltage measurements made me think that it happens when the multimeter is making a reading.

I had one briefly and if I remember correctly it was doing the same. I think it's the relay for the auto cal (auto zero).

[mnementh]

Seriously; what other answer did you expect, asking that question in here?

"Put a lamp on top of it."   

mnem
*halfheartedly lobs a few soggy ol' sneakers in the general direction of Hamburg*

[Atomillo]

There's however one thing that worries me: one can periodically hear what seems like three very quiet and faint beeps, which by hearing it in long integration time voltage measurements made me think that it happens when the multimeter is making a reading.

I had one briefly and if I remember correctly it was doing the same. I think it's the relay for the auto cal (auto zero).

Thanks for the info! I will sleep easier tonight.

[Cerebus]

Sorry if I mispelt Cerebrus Cerebus, but this particular string of character does not mean anything to me so it's hard to memorize it properly, just like yours, that's why I prefer to call you dwagon because dwagon is a word i know, so I am unlikely to mispell it.

That said I think Cerebus is plenty capable enough of speaking for himself, if he deemed it necessary. It's not like he was a timid 5 year old in w heel chair that needed you protection....

I never heard you lecture anyone on how to spell tggzzz which nobody can get right. Neither did I of course, but I was so tired of not knowing how to spell it that I eventually tried and found a way to remember it, in case it helps others... The repetition rate of the letters increases by one with each passing letter. So " T " is written only once, then the second letter " G " is written twice, and third letter " Z " is written 3 times. 1-2-3 times TGZ = TGGZZZ.   

For Cerebus I guess it's easier. Since it looks like I get the end wrong, brus instead of bus... I can just say that it's like an electrical bus, I2C or whatever... easy enough.

It's a communications protocol where you communicate by sending severed body parts of your enemies. 

Funnily enough it's probably all a spelling error. Dave Sim insists that the meant to spell Cerebus that way. His ex-wife Deni says he was aiming for Cerberus (aka Cerberos, aka Kerberos, aka Κέρβερος, the name of the triple-headed dog of Hades in Greek myth). I'm tending toward believing the one who reads instructions for things, and will stop and ask for directions when lost instead of the one whose genetic handicap stops them from doing both those things.

[Ice-Tea]

100mV on the battery. I'm guessing that's not a good thing.

[Zucca]

Has anybody an idea, what this could be and where it is used?

This is an adhesive strip, about 30cm long and on one side there are two metallised strips of an unknown material.

ESD strips for guests in electronic production lines/facilities.
One side needs to touch your leg and the other sticks on the bottom of your shoe.