Test Equipment Anonymous (TEA) group therapy thread

[med6753]

I saw that movie for the first time at a drive-in theater all of us packed into a 1962 Ford Falcon. 

[mnementh]

I know it's a day early.

"Down with the British!" 

https://youtu.be/tX5ZRE26YWM

 

FUCK YEA! 

If only it were a joke... 

mnem
'murrica!!! cuz... 'MURRICA!!!

[mnementh]

Didn't I just say that? *Goes back to revise his post with even more pessimistic figures* And that? 

Yes, you did mention derating, but I hadn't got that far through the list of unread messages.

No, ISTR you only mentioned derating to 25%, and I note that your last change was made after I posted derating by 80%-90%, i.e. to 10%-20%

Hence the part about *Goes back to revise his post with even more pessimistic figures* ... 

   Truthfully, I have yet to see real-world examples any more extreme than about 25% of rated capacitance. That figure was drawn from personal experience; comparing banks of MMLCCs against electrolytics in terms of how EFFECTIVE they were at filtering in the EMI-hostile environment of RC electronics. I did the maths a few times back when, setting up a RC bridge and calculating backwards to see what the actual capacitance was at operating voltage; however the crazy-low ESR of dozens of MMLCCs in parallel on big heavy 4oz copper fills makes it a moot point; you can get a lot better brute-force filtering AND RF decoupling with much lower actual capacitance. 

When you cram four 30-60A high-frequency 3-phase H-gate motor controllers into a 35mm x 35mm-ish footprint, then stack a STM32F4-F7 on top of that to control all their processors, THEN add bidirectional 900MHz-2.4 GHz digital radio control AND 5.8GHz analog / digital video transmission from 200-2000mW all in a 200mm or smaller aircraft... I can't think of a more EMI/RFI hostile environment that you'll run into in everyday life. 

On top of all that, most of this is experimental hobbyist-grade electronics designed by AMATEURS... It's a wonder ANY of these thing stay in the air for more than 30 seconds. 

OTOH, it's been great fun watching the hobby evolve literally from popsicle sticks and pager motors to purpose-built 1600W BL motors and custom-CNC aerospace-grade CF plate & tube. 

mnem
*vertical*

[Specmaster]

Anybody got any idea on how to use these at all? I saw them advertised as tools to remove pins from multipole plugs to enable reconnection of cables etc but they arrived with no instructions in the usual Chinese way and I've tried every way I can think of but so far have not been able to remove any pins what so ever 

[xrunner]

They would probably push down on the metal flare on the pin that keeps the pin in the connector. You can see it if you look into the plug on the outside of the pins.

[bd139]

If you can slide one onto each finger and wave your hand at someone else to get it done it might be more effective 

[Specmaster]

They would probably push down on the metal flare on the pin that keeps the pin in the connector. You can see it if you look into the plug on the outside of the pins.

Thanks, your right, I thought I'd tried that as well without success but just tried it and it worked, so maybe I used the wrong one.

[Specmaster]

If you can slide one onto each finger and wave your hand at someone else to get it done it might be more effective 

In your direction maybe  , xrunner has just pointed it out to, so I must have used the wrong pin before 

[xrunner]

They would probably push down on the metal flare on the pin that keeps the pin in the connector. You can see it if you look into the plug on the outside of the pins.

Thanks, your right, I thought I'd tried that as well without success but just tried it and it worked, so maybe I used the wrong one.

Damn I got something right!

I'm holding at this point for the rest of the day. 

[mnementh]

   Anybody got any idea on how to use these at all? I saw them advertised as tools to remove pins from multipole plugs to enable reconnection of cables etc but they arrived with no instructions in the usual Chinese way and I've tried every way I can think of but so far have not been able to remove any pins what so ever 

   You got the wrong kit. That kit is to remove the locking clips inside automotive plugs like these and then remove the pins themselves.


You're looking for the kit to dismantle MOLEX, etc stuff commonly used on computers & peripherals, right?

   Like this: eBay auction: #5030056250

MOLEX typically use the tubular one. You might be able to use one of those fork ones, as long as you rotate it just right so the forks meet the locking blades in the pin.

I have this kit: https://smile.amazon.com/gp/product/B07R4MCBQJ/

And this kit: https://smile.amazon.com/Konsait-Modding-Removal-Computer-Connector/dp/B0171RDCWW/

Between them, I can dismantle pretty much any electrical connector (there is some overlap, but the tubular MOLEX thing and the fan plug thing are much more convenient) and pick most cheap locks. 

mnem
*connected*

[tggzzz]

Truthfully, I have yet to see real-world examples any more extreme than about 25% of rated capacitance.

I've done zero measurements, other than to note that some RC risetimes look very unexponential on scopes.

I have seen data sheets indicating 80/90% derating - kudos to the manufacturer for stating it.

I have seen measurements by individuals[1] on other forums, and I'm sure TAoE X-chapters will mention values.

[1] that I trust w.r.t. electronics, but not other topics

[mnementh]

That has been EXACTLY my experience as well. While I've seen some documentation showing much more drastic figures from other sources, all my own personal experience has been much less frightening. 

But STILL frightening enough to always keep that derating slope in mind when working with the little bastards. 

mnem
If only my experiences with other people were so benign. 

[Specmaster]

@mnem, yes that is what I was looking for to extend some cables on an amplifier so I could flip the pcb over while it was powered and take some measurements, had to resort to splicing in some cable and heat shrinking it. 

[nixiefreqq]

“There! His Majesty can now read my name without glasses. And he can double the reward on my head!”
― John Hancock

take that ya' limeys!  (i include the dragon in with you guys since he is practically canadian these days).

[mnementh]

Lick me. };=)~~~~<

mnem
It's Okay... I'm DC.

[mnementh]

And now for something completely... ON TOPIC!!! 

   It's twins!      eBay auction: #133017269362

I posted this auction a few days ago... after a while it started niggling at me, so I made a lowball offer of $33 each anticipating approx $38 shipping per eBay. Seller accepted, but stated shipping would be $56 for the two. After some going back & forth it turned out there was something wrong in my eBay dashboard; the $38 shipping it reported was to some random ZIP in CA.  My shipping SHOULD have shown as $58 EACH, which is what eBay later tried to charge me. 

Anyhow... After a little more back & forth with their shipping dept I got an invoice for the correct amount of $122 which I just paid, and hopefully they'll be here next week.

I'm actually more than a little stoked, even though shipping was $20 more than I'd planned... These are very similar to my old favorite Lambda supply, only about twice the current. 2 x 40V @ 5A and series-stackable is quite a nice little bit of power. 

I'm thinking that I MIGHT 3DP a new faceplate similar in design to that 454 front cover to tie them together and put modern panel meters with a digit or two more in place. 

mnem
I feel... juicy.

[nixiefreqq]

geeeeeze louise mnem!

nice supplies......but aren't you supposed to be reorganizing and downsizing for the move?

you really do have a monkey on your back!

nice score anyway.

[mnementh]

Yeah... that's the only reason they had "a few days" to niggle at me. I TRIED to talk myself out of them... I REALLY DID.   

But even the "You're moving, dumbass!" argument proved unconvincing... I just said to myself:

"For THOSE juiceboxes, I'll jettison one of the THREE air compressors I have to make room!!!"

"B-b-b-ut..." 

"AND A PLANE, IF I HAVE TO!!!"   

Myself tried to put up a brave front and talk me down to just one, but we both knew the battle was lost in that instant... 

mnem
If nothing else, I am a creature of strong convictions.

[Terry01]

Yeah... that's the only reason they had "a few days" to niggle at me. I TRIED to talk myself out of them... I REALLY DID.   

But even the "You're moving, dumbass!" argument proved unconvincing... I just said to myself:

"For THOSE juiceboxes, I'll jettison one of the THREE air compressors I have to make room!!!"

"B-b-b-ut..." 

"AND A PLANE, IF I HAVE TO!!!"   

Myself tried to put up a brave front and talk me down to just one, but we both knew the battle was lost in that instant... 

mnem
If nothing else, I am a creature of strong convictions.

LOL 

[bd139]

Busy soldering this evening. Next two K2 modules turned up finally. So it's now equipped with an audio filter and SLA battery.

Audio filter board fits on the back of the control board. Has a nice low pass filter that gets rid of a lot of hiss off SSB. Also a very very narrow 600Hz filter for CW. Literally you tune across the band and can hear mush, find a CW signal and drop the IF and audio filters in and you can't hear a damn thing other than the signal. Also has a digital clock built in. Amazing bit of engineering. You can see the frequency counter probe and counter interface there as well (keeping it TE)



Battery fits in top of case:



Decided I'd take the side off to illustrate how crammed this thing is:



Weighs a fair bit now but not as much as an FT818, external battery and external tuner!

Now for a transport case that fits in my ruck sack and I'm off up some hills.

[med6753]

The best thing about building a kit like yours is the pride and satisfaction in knowing that you did it yourself.  I miss that and if someone made TE kits I'd be all over it.   

[bd139]

Hell yeah so would I. Imagine a decent bench power supply, DMM, counter etc in that enclosure and form factor.

[bitseeker]

And now for something completely... ON TOPIC!!! 

   It's twins!      eBay auction: #133017269362

I posted this auction a few days ago... after a while it started niggling at me, so I made a lowball offer of $33 each anticipating approx $38 shipping per eBay. Seller accepted, but stated shipping would be $56 for the two. After some going back & forth it turned out there was something wrong in my eBay dashboard; the $38 shipping it reported was to some random ZIP in CA.  My shipping SHOULD have shown as $58 EACH, which is what eBay later tried to charge me. 

Anyhow... After a little more back & forth with their shipping dept I got an invoice for the correct amount of $122 which I just paid, and hopefully they'll be here next week.

I'm actually more than a little stoked, even though shipping was $20 more than I'd planned... These are very similar to my old favorite Lambda supply, only about twice the current. 2 x 40V @ 5A and series-stackable is quite a nice little bit of power. 

I'm thinking that I MIGHT 3DP a new faceplate similar in design to that 454 front cover to tie them together and put modern panel meters with a digit or two more in place. 

What is this? A Lambda fest? Geez, I bet some are going to start showing up on my bench, next.

I'm curious if the faceplate on this generation of power supplies is as brittle as the old beige ones. These seem not to show up with missing corners, so they seem more durable.

If you're going to make your own faceplate, there's plenty of room to add additional meters, too. I hate having to toggle between voltage and current!

[VK5RC]

Lovely stuff from Elecraft, I am trying to get into a bit more SOTA (for non-hams Summits On The Air - a point system you get points for getting off your a**e, climbing a hill/mountain and making a radio contact)
The electromagnetic smog at my home is deafening. I use an Yaesu ft817 and elecraft's random wire tuner with a LiFe battery, solar panel if longer stay. Hardest part is bringing a chair, tarpaulin to keep nature at bay.
Rob

[med6753]

Hell yeah so would I. Imagine a decent bench power supply, DMM, counter etc in that enclosure and form factor.

All the Heathkits I built years ago and then like a dumb ass sold. I guess that's when I saw that OL-1 and no matter how bad it was I was determined to get going. Neither years of crud or shitty assembly mattered. And after I get back from vacation going to rip into the S-3 Electronic Switch (have all the parts needed) and then the AG-9A Audio Generator.