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Products => Test Equipment => Topic started by: slugrustle on August 02, 2022, 01:27:26 am

Title: Useful "non-standard" test equipment
Post by: slugrustle on August 02, 2022, 01:27:26 am
I'm curious what test equipment people find the most handy or useful that isn't "standard" test equipment.

What I mean by standard: Something that, if you wanted to buy one, you'd go to a test equipment website.  For example, oscilloscope, DMM, lab supply, signal generator, E-Load, frequency counter, spectrum analyzer, source measure unit, electrometer, thermocouple reader, current clamp, logic analyzer, etc. 

What I mean by non-standard: Anything that's useful for electronics testing that doesn't fit in the list above.  For example, maybe you find it really handy to have a certain kind of diode around or a really big heatsink / cold plate.  Maybe you're fond of using incandescent light bulbs as a load.  Stuff like this.
Title: Re: Useful "non-standard" test equipment
Post by: JohnG on August 02, 2022, 01:37:45 pm
Some odds and ends I have used over the years:

RF coil tuning trend tool: a piece of small plastic tubing about 10 cm long and 3 mm diameter, with a small ferrite cylinder in one end and a small aluminum cylinder in the other. You can use it to raise or lower the inductance of small aircore inductors temporarily to see which way they should go for some quick and dirty tuning. A few pF cap mounted to the end of a stick is also useful.

Light bulb bank (5x 40W bulbs): electrically robust load with inherent power limiting.

A collection of big MOSFETs (different voltages) mounted to heat sinks, with gate and source shorted: They are like giant Zener diodes, and I use them for overvoltage protection in case some goes wrong. Test them first, but many newer MOSFETs can take a continuous avalanche if you can keep the temp under control.

A box of toothpicks and outdated business cards: great for mixing glue and adhesives.

John

Title: Re: Useful "non-standard" test equipment
Post by: nctnico on August 02, 2022, 02:25:04 pm
A small box with a switch that connects to 3 banana sockets (common, normally open, normally closed). Comes in handy every now and then.
Title: Re: Useful "non-standard" test equipment
Post by: TopQuark on August 02, 2022, 02:53:13 pm
My new favourite new piece of non standard equipment: https://www.eevblog.com/forum/testgear/yg520c-desktop-shielded-chamber/ (https://www.eevblog.com/forum/testgear/yg520c-desktop-shielded-chamber/)
Gets rid of interferences like nothing else, making sure you are only measuring the DUT and not the environment. I've tried to make my own, but this is just so much better.

Below are not exactly test equipment, but tools that lives on my bench, tools that I can't live without.

"Precision" box cutter with blade lock. Blade holder is made out of two pieces of durable coated metal, with a small tab at the back that allows you to flip down and clamp the blade solidly in place between the two piece construction. There's no wobble to the blade when it is locked. I like this way more than a xacto knife because you can just snap off the end of the scored blade for a fresh sharp edge, much faster than changing blades on a xacto knife. I use this box cutter for everything, scraping away solder mask, cutting traces in two, cutting a trace out of a copper clad, slicing copper away from copper clad. It maybe just a box cutter, but it is precise enough I can easily scrap away solder mask covering tiny vias underneath BGAs without damaging the via itself.

Swiss made mod wire stripping tweezers. Wire stripper that cleanly and effortlessly strips 30 awg mod / wire wrap wire, nothing more, nothing less. It is a very specific tool that does a very specific job, but when you need to strip tens or hundreds of mod wires, nothing beats it.
Title: Re: Useful "non-standard" test equipment
Post by: free_electron on August 02, 2022, 03:00:34 pm
 a ball of plasticine. useful for tacking boards or small parts down when soldering... especially difficult parts like tqfps . tack em on the corners.
Title: Re: Useful "non-standard" test equipment
Post by: TopQuark on August 02, 2022, 03:02:22 pm
Oh and how can I forget my DIY B Field probe. Made out of a piece of 047 rigid coax, dipped in epoxy and spray painted red for 200 MHz extra bandwidth /s

Has an aperture of around 5mm. Super handy for pin pointing issues on a circuit board. You can stick this probe right to the power input pin of an IC to see it's current consumption transients for example.
Title: Re: Useful "non-standard" test equipment
Post by: TimFox on August 02, 2022, 03:39:56 pm
When working with RF circuitry before retirement, I found these ATC "tuning stick" sets (small capacitors with short leads on end of plastic sticks) to be useful.
https://rfs.kyocera-avx.com/order/design?kit=MLC%20Tuning%20Stick
Title: Re: Useful "non-standard" test equipment
Post by: AVGresponding on August 02, 2022, 07:16:23 pm
Home made 4-wire short. No solder, low mass, made from a single piece of high quality solid core conductor, all to get as low a thermal EMF as possible without spending daft money.

(https://www.eevblog.com/forum/testgear/useful-non-standard-test-equipment/?action=dlattach;attach=1555936)
Title: Re: Useful "non-standard" test equipment
Post by: vk6zgo on August 04, 2022, 08:46:32 am
When working with RF circuitry before retirement, I found these ATC "tuning stick" sets (small capacitors with short leads on end of plastic sticks) to be useful.
https://rfs.kyocera-avx.com/order/design?kit=MLC%20Tuning%20Stick
Good idea---beats pushing'em around with toothpicks! ;D
Title: Re: Useful "non-standard" test equipment
Post by: Atomillo on August 04, 2022, 09:12:37 am
Home made 4-wire short. No solder, low mass, made from a single piece of high quality solid core conductor, all to get as low a thermal EMF as possible without spending daft money.

(https://www.eevblog.com/forum/testgear/useful-non-standard-test-equipment/?action=dlattach;attach=1555936)


I would only advise regular cleaning before measurements in order to avoid the thermal EMF generated in the interface between copper and copper oxide.
In a sense, one wants the maximum area of exposed copper to minimize resistance but on the other the more copper surface there is (without any protection like for instance gold plating) makes oxide more likely to appear.
Title: Re: Useful "non-standard" test equipment
Post by: rsjsouza on August 04, 2022, 12:05:24 pm
When working with RF circuitry before retirement, I found these ATC "tuning stick" sets (small capacitors with short leads on end of plastic sticks) to be useful.
https://rfs.kyocera-avx.com/order/design?kit=MLC%20Tuning%20Stick
Good idea---beats pushing'em around with toothpicks! ;D
These things seem interesting, but I am too dumb to figure out how they actually work (or find information about this). The design kit brochure and the photographs do not help in providing usage information. How do they work?
Title: Re: Useful "non-standard" test equipment
Post by: themadhippy on August 04, 2022, 12:21:37 pm
 A wooden  drumstick ,great for prodding and poking things in industrial panels.
Title: Re: Useful "non-standard" test equipment
Post by: TimFox on August 04, 2022, 01:38:25 pm
When working with RF circuitry before retirement, I found these ATC "tuning stick" sets (small capacitors with short leads on end of plastic sticks) to be useful.
https://rfs.kyocera-avx.com/order/design?kit=MLC%20Tuning%20Stick
Good idea---beats pushing'em around with toothpicks! ;D
These things seem interesting, but I am too dumb to figure out how they actually work (or find information about this). The design kit brochure and the photographs do not help in providing usage information. How do they work?

The photo may be hard to see.  Each one in the kit is a plastic stick, several inches long.  On the end is a chip capacitor with short stiff wires soldered to the terminations.  The capacitor is held to the stick with heat-shrink tubing.
One uses it by pushing it against the pads or terminations of a similar capacitor on a surface-mount board to increase the capacitance there.
Title: Re: Useful "non-standard" test equipment
Post by: AVGresponding on August 04, 2022, 05:19:43 pm
Home made 4-wire short. No solder, low mass, made from a single piece of high quality solid core conductor, all to get as low a thermal EMF as possible without spending daft money.

(https://www.eevblog.com/forum/testgear/useful-non-standard-test-equipment/?action=dlattach;attach=1555936)


I would only advise regular cleaning before measurements in order to avoid the thermal EMF generated in the interface between copper and copper oxide.
In a sense, one wants the maximum area of exposed copper to minimize resistance but on the other the more copper surface there is (without any protection like for instance gold plating) makes oxide more likely to appear.

Yep. Fortunately it's rarely humid here, so shouldn't oxidise much. I wonder if it would be worth getting one of those gold plating kits? I don't imagine making one out of gold wire would be cheap...
Title: Re: Useful "non-standard" test equipment
Post by: spostma on August 04, 2022, 07:14:21 pm
for me, the Erem 15AGW Cutting tweezer is indispensible for all fine cutting and stripping work:

https://www.newark.com/erem/15agw/smd-tweezer-bent-flat-4-5-carbon/dp/50B8499 (https://www.newark.com/erem/15agw/smd-tweezer-bent-flat-4-5-carbon/dp/50B8499)
Title: Re: Useful "non-standard" test equipment
Post by: Atomillo on August 04, 2022, 07:24:31 pm
Home made 4-wire short. No solder, low mass, made from a single piece of high quality solid core conductor, all to get as low a thermal EMF as possible without spending daft money.

(https://www.eevblog.com/forum/testgear/useful-non-standard-test-equipment/?action=dlattach;attach=1555936)


I would only advise regular cleaning before measurements in order to avoid the thermal EMF generated in the interface between copper and copper oxide.
In a sense, one wants the maximum area of exposed copper to minimize resistance but on the other the more copper surface there is (without any protection like for instance gold plating) makes oxide more likely to appear.

Yep. Fortunately it's rarely humid here, so shouldn't oxidise much. I wonder if it would be worth getting one of those gold plating kits? I don't imagine making one out of gold wire would be cheap...

Not only that but I suspect the plating would fall over time. In my opinion the best course of action is just cleanliness and being thorough. Besides, in most nanovolt measurements you already have to worry about things like the phase of the moon so just another thing more isn't so bad!
Title: Re: Useful "non-standard" test equipment
Post by: JohnG on August 04, 2022, 08:07:03 pm
[attach=1]

I keep meaning to pull out the center row, because sometimes its a pain to connect to the innermost binding posts. In never happens, probably because it would take me more time than it is worth.

John
Title: Re: Useful "non-standard" test equipment
Post by: pdenisowski on August 05, 2022, 02:21:32 pm
Can't recall if I posted this before, but I recently was trying to find a high current (40A) load for some testing / demonstrations

After experimenting with batches of cement resistors suspended in mineral oil, I took the easy way out and simply bought a cheap automotive battery tester.  Works great :)

[Please don't try this at home ...]
Title: Re: Useful "non-standard" test equipment
Post by: pdenisowski on August 05, 2022, 02:31:19 pm
It used to be handy to have something like an AM radio handy at the bench.... You could maybe tell if your circuit was oscillating or glitching by the noise the receiver picked up from it.

This.  I used to do RF interference hunting / direction finding professionally (using the best equipment money can buy), and I used to half-joke that some interference sources were so bad that you could find them with an AM radio and a coat hanger. :)

Power line noise (i.e. noise radiating from outdoor electrical power distribution lines) could often be localized to within 100 meters or so simply by tuning to an "unused" AM radio frequency in your car and driving around until you heard the distinctive 60/120 Hz "growl" of power line noise.
Title: Re: Useful "non-standard" test equipment
Post by: duckduck on August 05, 2022, 06:42:26 pm
Relevant threads:

https://www.eevblog.com/forum/testgear/show-the-homemade-equipment-you-are-using-now/ (https://www.eevblog.com/forum/testgear/show-the-homemade-equipment-you-are-using-now/) - Check out the filthy hack jobs I built. If it works it looks beautiful to me.

https://www.eevblog.com/forum/testgear/diy-test-gear/ (https://www.eevblog.com/forum/testgear/diy-test-gear/)
Title: Re: Useful "non-standard" test equipment
Post by: jonpaul on August 05, 2022, 09:44:16 pm
your finger...detection of overheated parts ( beware of high voltage and burns...)

A rod of ferrite .tuning RF coils by raising inductance

a 1/4" x 8" long plastic rod with an NE-2 neon pilot lamp...détection of RF fields, and high voltage

Discarded dental tools...scraping solder resin, corrosion, many uses.....ask your Dentist!

Jon