Test Equipment Anonymous (TEA) group therapy thread

[beanflying]

TEA Question 

100-120VDC at 3A variable with current limiting. Anything old or used I should look at or do I buy a slightly dodgy 120V 3A switchmode off Aliexpress? Duty is Foam Cutting hot wire so some noise isn't an issue but I would also prefer not to get a kick out of life from using it.

https://www.aliexpress.com/item/4001133803791.html?spm=a2g0s.8937460.0.0.1e482e0eFnuCWM

If you really need 300W for foam cutting, and who's to say you don't, I would have thought that you've be better off with less voltage and more current. I personally wouldn't want to be playing about with an exposed resistance wire that had 100+ VDC across the ends of it. Plus it's much easier to find respectable high current low voltage SMPSs from the likes of Meanwell that it is to find a 300W odd PSU in the 3A or so region.

My last manual 1.2m bow ran 0.8mm Nichrome so 15-16V was fine. Problem with it was always the Kerf was fat so you needed to fudge the templates to allow for this. Not ideal but for one offs we made it work.

Come forward a few decades and to the current design of a new CNC cutter wire length is potentially 1.8m so wire drag and kerf is an issue so to reduce both wire comes down to 0.2 Nichrome or more likely Titanium. Based on the testing I have done with Titanium 90V at 1.5A would get it done. If I decide the 0.2 is not lasting long enough then 0.3 or 0.4 will get used for general use but then the current comes up and voltage down to likely 50V.

[mnementh]

Currently writing CGI scripts in Perl, to control hardware via TELNET.

Will serve them on Port 80, using HTTP.  In a frameset.

Do note that this technology is 20 years newer than the Tek 547.

Aaaand Done! The equally ancient revision control system (RCS) reports release date as 2018, which is because I've been developing away from the source tree. Just fixed that, but can't be arsed to swap the pic.

So, what's this then? I've got an Extron matrix, that routes balanced audio in my home stereo. It takes commands over either front panel, RS232 or MIL-STD-1782, and this update is from the former to the latter; my old one was RS-232 only. I've recently got a "new" one off of Ebay for peanuts and expanded from 8x8 to 12x8, and got a network interface. (The Ebay procedure was a pain -- at first I bought what I thought was an audio matrix, but was sent a S-video one. Successfully contested that and was refunded, while keeping the matrix. Second try was even cheaper, and correct. )

But, the old web server using basically the same technology and a serial line, was decommissioned. And I finally got a large enough supply of boredom and round tuits that I sat down and taught myself Net::Telnet.

As it turns out, doing things over telnet is much easier than fighting timing and delays over serial. I removed a lot of bodges and cleaned things up. While I was at it, I also put a panic button and some Squeezebox controls in. The panic button sends "tear all crosspoints out" and the Squeezebox controls are another telnet, to the server application running on another port on the same machine.

The security model is based on layers. The server sits on a network that can't talk to the Internet, not even through NAT. Computers that can reach it are supposed to be controlled only by trusted people. There are holes in this large enough to pass an ocean liner through, but I'm OK with that, after some in-depth security analysis, mostly in form of hand-waving.

The most modern part here of course is the use of CSS for formatting. In contrast to Javascript I think that CSS constitutes actual progress, inasmuch as it's a continuation of the split between content and formatting. Frankly, I hate frontend development. The most refined interface is the command line. The rest is just lazyness.

Should I be worried that most of this actually made sense to me...? Having worked a fair bit with the older Extron gear, I know what a joke the security is... for a while there, their "tablet controllers" consisted of a small tablet PC running embedded WindowsXP which was directly connected, with zero sandboxing or VPN, to the internet AND to the client's internal network. 

When I was having trouble with one install due to the fact it had been migrated from a different location, I found while working with my helldesk support that the remote was actually still connected to a conference room in another state... and the work I was doing was making that conference room, still in use, go batshit crazy during two meetings. 

As an aside; I especially like the [BRB] prominently displayed at the bottom of your "console".

mnem
 

[mansaxel]

KISS would be to do what I do, use a foot pump. One wonders if all this boasting about the size of one's compressor isn't some kind of compensatory displacement activity.

Oh, indeed, but the drill, stapler, air ratchet, and other consumers work so badly from a hand pump. Filling air is just a sideshow to the real needs, which are more shop related.

For air refill, I bought a very cheap instrument, but in the name of TE immediately removed the gauge it came with and replaced it with a separate sourced Empeo, made in Germany. It cost twice the price of the rest of the filler, but improved the instrument greatly. This is the kind of filler I've got.

[mnementh]

TEA Question 

100-120VDC at 3A variable with current limiting. Anything old or used I should look at or do I buy a slightly dodgy 120V 3A switchmode off Aliexpress? Duty is Foam Cutting hot wire so some noise isn't an issue but I would also prefer not to get a kick out of life from using it.

https://www.aliexpress.com/item/4001133803791.html?spm=a2g0s.8937460.0.0.1e482e0eFnuCWM

Use your LiPo charger. If it has the Junsi FW, it likely has motor testing and foam cutting drive in the SPECIAL MODES Menu:



All the parameters are adjustable, as is the safety timer.

mnem
 

[GreyWoolfe]

And in other news.....USPS is just plain laughable. That 6BY8 tube that was supposed to be delivered on Monday went from a Newark, NJ distribution center to a Kearney, NJ distribution center and still is not enroute to my local area. 

3 miles from Newark to Kearney, what they do, give it to the low man on the totem pole and made him hand deliver it, crawling on his hands and knees the entire way whilst holding the tube in his mouth?  Disinfect the package when it gets there just in case.

[med6753]

And in other news.....USPS is just plain laughable. That 6BY8 tube that was supposed to be delivered on Monday went from a Newark, NJ distribution center to a Kearney, NJ distribution center and still is not enroute to my local area. 

3 miles from Newark to Kearney, what they do, give it to the low man on the totem pole and made him hand deliver it, crawling on his hands and knees the entire way whilst holding the tube in his mouth?  Disinfect the package when it gets there just in case.

Since it's spending all that time in Jersey I may have to burn it. 

[mnementh]

snip

The +100V goes all over the scope and provides series string filament voltages to the tubes, including the plug-in. .

Looked at the heater wiring diagram and PSU schematics. Unless I am misguided, it looks like it's not at all like that ??
All filaments are in parallel not series, and they are supplied via various 6,3V AC windings, each powering some subset of the tubes. Not powered via that +100V.

snip

It will probably depend on the plug in (some 1 series have no tubes, or only a couple of nuvistors), but powering the plug in tubes by series DC is a pretty common trick Tek used on the 500 series to reduce noise in the front end and possibly other strategic places.

Doesn't that suggest possibly a leaky diode as culprit...?

mnem
 

[mnementh]

my car tyre inflator basically consists of a mains powered compressor that is run off 2 large boat (or car) batteries hooked up to a Meanwell true sine wave 1kW inverter. That may seem like overkill, but actually works.

My car tyre inflator is called ATLAS COPCO and runs on 400V AC three-phase. For when I'm away from the garage, I've got a smartphone app that allows me to call assistane (AA / ADAC style but not tied to a membership) regardless of which car I'm driving and regardless where in Europe I am. But for a flat tire I don't. I swap it, since I've got a spare and tools in the car. And I check the pressure on the spare regularly.

My tyre inflator is just a good common sense one, one that I keep in its protective pouch in the boot, and it also doubles as a powerful torch. When required it simply clips onto the car battery terminals and has 2 switches, 1 for the compressor and the other for the torch, I believe in the KISS principle 

KISS would be to do what I do, use a foot pump. One wonders if all this boasting about the size of one's compressor isn't some kind of compensatory displacement activity.

Now I am back to having a sand capable vehicle again I have a good one on the shopping list. Re inflating 4 large tires from 8-10 PSI to road pressure by foot is a workout I don't need I do have a cheapy direct drive compressor as well at home but doing shed things which does all I need at this stage.

Yeah; KISS Principle here was:

A) Need to air up tyres from winter storage.

1) Sit in front of PC with cup of coffee.
2) Find used 20 gallon DD air compressor for CAD$50 with hoses and a coffee-can full of accessories. Take your pick of oodles within easy drive.
3) Drive 10 minutes; buy it, have 10 minutes casual interaction with another human being for the first time in months.
4) Take it home and plug it in; still be done with the actual work part before I could foot-pump 2 modern oversized SUV tires with 17-19" wheels.
5) Enjoy not getting blisters on your feet.
6) Lather, rinse, repeat for however long your used air compressor lasts.

mnem
 

[mnementh]

TEA Question 

100-120VDC at 3A variable with current limiting. Anything old or used I should look at or do I buy a slightly dodgy 120V 3A switchmode off Aliexpress? Duty is Foam Cutting hot wire so some noise isn't an issue but I would also prefer not to get a kick out of life from using it.

https://www.aliexpress.com/item/4001133803791.html?spm=a2g0s.8937460.0.0.1e482e0eFnuCWM

If you really need 300W for foam cutting, and who's to say you don't, I would have thought that you've be better off with less voltage and more current. I personally wouldn't want to be playing about with an exposed resistance wire that had 100+ VDC across the ends of it. Plus it's much easier to find respectable high current low voltage SMPSs from the likes of Meanwell that it is to find a 300W odd PSU in the 3A or so region.

My last manual 1.2m bow ran 0.8mm Nichrome so 15-16V was fine. Problem with it was always the Kerf was fat so you needed to fudge the templates to allow for this. Not ideal but for one offs we made it work.

Come forward a few decades and to the current design of a new CNC cutter wire length is potentially 1.8m so wire drag and kerf is an issue so to reduce both wire comes down to 0.2 Nichrome or more likely Titanium. Based on the testing I have done with Titanium 90V at 1.5A would get it done. If I decide the 0.2 is not lasting long enough then 0.3 or 0.4 will get used for general use but then the current comes up and voltage down to likely 50V.

Ahhh... NM then. Didn't realize you were building a production machine. What is the purpose here...? Tall stacks of multiple copies all at once, or is cutting with LASER NCE as just too wasteful of the LASER's lifetime...? I know you said you really like the results with your CNC LASER.

mnem
 

[ch_scr]

I might have finally scored me a new 2nd hand Thinkpad (on the ol' gumtree). Real deal if it goes down. Pickup later this evening, wish me luck 
That could mean I can finally put that topic to rest... at least for the next years...

[bd139]

Good luck  . I haven’t touched my T495 since I got that MacBook Air 

T495 might end up on eBay.

[ch_scr]

Well, it better go down NOW, I just spend 15 minutes cleaning the keyboard of my old one with a toothbrush.
Enough crumbs and hair for a birdsnest 

[mnementh]

Thanks to BangUgood for sending me a free sample of the comprehensive RF tester.
2 out of 2 not working, but i am sure that is just bad luck and these just slipped true quality control 
it is a real pity... if they check better what they send and how they send.. packaging.. it would be a nice device...

https://youtu.be/YrKRUExTtps

i so wanted to show you a nice compareison aside the Marconi...   guess the stars were not aligned

Yeah, I spent some time doing the BG Reviewer thing back when I was playing with the Tiny Whoop-class micro-quadcopters; you're not the only one who's received busted-ass stuff from them for review. You'd think they would take a moment to make sure a unit going to a reviewer at least works before they ship it out; and when you try to get things sorted with them to have something you can actually review, they treat you like they're doing you a favor. 

This strange attitude towards what Westerners consider "proper customer service" is something I've encountered in many different product markets, not just RC toys. That recurring experience (along with nearly universal shamelessly cut-throat dealings with channel partners and even those who bankroll their business) is one of the main reasons I keep repeating that our Asian cousins simply do not think the same way we do about such things.

Cheers,

mnem
As always, take with a pinch of salt big enough to pickle a dwagon; IMHO, YMMV, DQMOT, WTFBBQ, DILLIGAF...?

[Robert763]

Today's ramblings and misfortunes....

According to the latest tracking the 6BY8 tube is still stuck at the Kearny, NJ distribution center with no delivery date. Ya think I might get it before Christmas? 

Replacement tubular/coupling caps for the Type 547 PSU are in the hands of FedEx with an expected delivery of Friday.

Discovered that the Type 547 PSU does NOT sequence up the same as the Type 535A PSU even though they are the same basic design. Both the +100V and -150V reference are held off at essentially 0 volts until the time delay kicks in. The Type 535A brings the +100V up to +70V and then the time delay kicks in. So that smoking gun was a flaming fart. 

What I'm basically left with is despite a good power off DC resistance to ground there has to be some sort of short that only appears when power is applied. What could that possibly be? I have a thought. The +100V goes all over the scope and provides series string filament voltages to the tubes, including the plug-in. There MIGHT be a tube that has a filament to cathode short that only shows itself when the tube heats up. So today I'm going to concentrate on isolating sections of the +100V, apply power, and see what happens. This is going to be no easy feat because as stated the +100V goes all over.

Good possibility that procedure is going to involve magic smoke.     

KISS
Pull the plug-ins and all the valves (tubes), except those in the PSU. Then power up. If no smoke start plugging back in in logical order.

[beanflying]

TEA Question 

100-120VDC at 3A variable with current limiting. Anything old or used I should look at or do I buy a slightly dodgy 120V 3A switchmode off Aliexpress? Duty is Foam Cutting hot wire so some noise isn't an issue but I would also prefer not to get a kick out of life from using it.

https://www.aliexpress.com/item/4001133803791.html?spm=a2g0s.8937460.0.0.1e482e0eFnuCWM

If you really need 300W for foam cutting, and who's to say you don't, I would have thought that you've be better off with less voltage and more current. I personally wouldn't want to be playing about with an exposed resistance wire that had 100+ VDC across the ends of it. Plus it's much easier to find respectable high current low voltage SMPSs from the likes of Meanwell that it is to find a 300W odd PSU in the 3A or so region.

My last manual 1.2m bow ran 0.8mm Nichrome so 15-16V was fine. Problem with it was always the Kerf was fat so you needed to fudge the templates to allow for this. Not ideal but for one offs we made it work.

Come forward a few decades and to the current design of a new CNC cutter wire length is potentially 1.8m so wire drag and kerf is an issue so to reduce both wire comes down to 0.2 Nichrome or more likely Titanium. Based on the testing I have done with Titanium 90V at 1.5A would get it done. If I decide the 0.2 is not lasting long enough then 0.3 or 0.4 will get used for general use but then the current comes up and voltage down to likely 50V.

Ahhh... NM then. Didn't realize you were building a production machine. What is the purpose here...? Tall stacks of multiple copies all at once, or is cutting with LASER NCE as just too wasteful of the LASER's lifetime...? I know you said you really like the results with your CNC LASER.

mnem
 

Going to set it up on the roof for tonights 3am Possum and quarterize the problem 

Standard foam blocks are 1.2m wide is part of it for the width then when you want to run angled cuts you need a longer wire (still working on ideas for tension controlled drum for the wire).  So for making blanks for additional cutting and working with stock 1.2m is needed. Part of the use planned will be wing cutting so 900-1200 wide sections are fairly normal but there is then non R/C cutting which opens up all sorts of avenues for a $.

[mansaxel]

Should I be worried that most of this actually made sense to me...? ... worked a fair bit with the older Extron gear ...

And I'm aiming for more! Currently planning for a video system with an Extron HDMI matrix in the middle. Same control model, so very easy to integrate. Goal is to have routing to and from SDI (cheap chinese gateways and 75Ω coax...) so I can do a HD playout server / mixer in the datacentre, and have it go to various HDMI sources. Also planning an audio embedder.

As an aside; I especially like the [BRB] prominently displayed at the bottom of your "console".

mnem
 

A panic button is good UI.

[duckduck]

Would it help to use a heat gun to persuade the oils to penetrate the leather?

Heat gun...? I suppose it might help. Never tried it; got enough to handle just holding the boot and cloth and trying to keep it all from flying off helter-skelter when I need to dip my rag in the tub of goopy...

Hair dryer is quite enough. 1100 degrees Freedom is not needed here.

EDIT:

while I've got a post...

More than all of the fuel stabilizer in the world, ethanol-free gasoline will help prevent small engines from getting gunked up. In a metal storage can, ethanol-free gas will stay good for several years. If you are in USA/Canada https://www.pure-gas.org/ can help you find a station that sells the stuff.

[mnementh]

A little elbow grease was actually quite enough in this case; the object was to protect and preserve a pair of work boots, not impress Admiralty.

mnem
 

[Robert763]

The back of a spoon heated over a candle was the old way of doing it.

[Neomys Sapiens]

A little elbow grease was actually quite enough in this case; the object was to protect and preserve a pair of work boots, not impress Admiralty.

mnem
 

[tonyalbus]

Thanks to BangUgood for sending me a free sample of the comprehensive RF tester.
2 out of 2 not working, but i am sure that is just bad luck and these just slipped true quality control 
it is a real pity... if they check better what they send and how they send.. packaging.. it would be a nice device...

https://youtu.be/YrKRUExTtps

i so wanted to show you a nice compareison aside the Marconi...   guess the stars were not aligned

Yeah, I spent some time doing the BG Reviewer thing back when I was playing with the Tiny Whoop-class micro-quadcopters; you're not the only one who's received busted-ass stuff from them for review. You'd think they would take a moment to make sure a unit going to a reviewer at least works before they ship it out; and when you try to get things sorted with them to have something you can actually review, they treat you like they're doing you a favor. 

This strange attitude towards what Westerners consider "proper customer service" is something I've encountered in many different product markets, not just RC toys. That recurring experience (along with nearly universal shamelessly cut-throat dealings with channel partners and even those who bankroll their business) is one of the main reasons I keep repeating that our Asian cousins simply do not think the same way we do about such things.

Cheers,

mnem
As always, take with a pinch of salt big enough to pickle a dwagon; IMHO, YMMV, DQMOT, WTFBBQ, DILLIGAF...?

Man... i rest my case.... and i wanted to make it work...they don't work with me.... and i am a positive guy.... man... what can i say.....
thanks for the even wors crap you send me when i paid for it?    guess that does sums it up..
well from there side... who is tony and those few 1000 watcing that.. we have biljons here... or other don't don't watch tony// 

[med6753]

A little elbow grease was actually quite enough in this case; the object was to protect and preserve a pair of work boots, not impress Admiralty.

mnem
 

(Attachment Link)

Not surprising when you use a Polaris missile as a sex toy. 

[med6753]

Today's ramblings and misfortunes....

According to the latest tracking the 6BY8 tube is still stuck at the Kearny, NJ distribution center with no delivery date. Ya think I might get it before Christmas? 

Replacement tubular/coupling caps for the Type 547 PSU are in the hands of FedEx with an expected delivery of Friday.

Discovered that the Type 547 PSU does NOT sequence up the same as the Type 535A PSU even though they are the same basic design. Both the +100V and -150V reference are held off at essentially 0 volts until the time delay kicks in. The Type 535A brings the +100V up to +70V and then the time delay kicks in. So that smoking gun was a flaming fart. 

What I'm basically left with is despite a good power off DC resistance to ground there has to be some sort of short that only appears when power is applied. What could that possibly be? I have a thought. The +100V goes all over the scope and provides series string filament voltages to the tubes, including the plug-in. There MIGHT be a tube that has a filament to cathode short that only shows itself when the tube heats up. So today I'm going to concentrate on isolating sections of the +100V, apply power, and see what happens. This is going to be no easy feat because as stated the +100V goes all over.

Good possibility that procedure is going to involve magic smoke.     

KISS
Pull the plug-ins and all the valves (tubes), except those in the PSU. Then power up. If no smoke start plugging back in in logical order.

That's the plan, but it didn't happen today. Got sidetracked with a bunch if other items including the pre-surigical doc calling and scaring the crap out of me with the results of my blood work only to tell me that my blood sugar was high. Well geez, tell me something I don't already know with the things that have been going on lately. I lost the ambition after that to work on it and decided to get outside in the fresh air and beat the shit out of the Civic. 

Maybe tomorrow. Stand by. 

[Neomys Sapiens]

Dude buys a 125€ scope. Gives me neutral feedback "Boxing could be better, CRT was dirty behind cover screen. For the rest product is OK as described.".

CRT was dirty??? What am I, a fucking window cleaner?? Christ.

*ice-tea out*

You supplied him with dirty videos? You should have charged extra!

Now there's a plan. Would put people on a better mood for sure.

Huh. Are we now going to see the pornification of the scope-clock? Definitely nothing for slow tubes.

[AVGresponding]

Well, just discovered the chances of the Agilent U1401B replacing my Fluke 289 as a daily driver are zero.

I'd left the batteries in it for a few days without charging, then when I next turned it on, it would work in measure mode, but not source mode, it just turned on momentarily then dropped out.
Ok time to check the batteries then.     4 of the 8 were down at ~1V, the other 4 at ~1.34V! What is going on here?!

I decided to use my latest bench acquisition (more on that later) to check the current consumption in the three "off" modes; there's a slide switch on the side of the meter to change between measure, source/measure, and charge.

There's an initial surge of around 24uA which drops to around 10uA when the batteries are connected in either m or s/m, and a whole 1mA when in charge mode (with the charger not connected). Definitely not enough to kill batteries in such a short time, though a little higher than I'd like (I'd like zero drain when off ideally...), as I didn't leave it in charge mode.

Pulled it apart to see if I could see either signs of magic smoke release or a dried up supercap. No on both fronts, though it is packed in there. There are at least three boards, a daughter-board, and a heatshrink wrapped thick-film hybrid...   

I eventually surrendered to common sense and resigned myself to RTFM.
Here's a copy-paste from the pdf on the power consumption and battery life section of the specs:

Power consumption
––
Battery charging: 9.3 VA typical
––
Sourcing of constant current at 25 mA, maximum load: 5.5 VA typical on 24 V DC adapter, 2.4 VA typical on 9.6 V batteries
––
Meter only: 1.8 VA typical on 24 V DC adapter, 0.6 VA typical on 9.6 V batteries

Battery life
Assuming fully-charged Ni-MH batteries:
Meter only: 20 hours (approximately)
Source/Meter: 4 hours (approximately)

  4 hours? 4 freaking hours?!?