Comments by "Stephen Villano" (@spvillano) on "DENKI OTAKU" channel.

And wound gets pronounced like wound, aka bullet wound vs wound as in what one does for a coil around a spool.
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Frankly, I'd never consider getting components from Amazon. If I need components, I'll order them from Digikey and call it a day.
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@DENKI-OTAKU anode got pronounced multiple wrong ways, wound vs wound (don't blame me for the language, wound as in a capacitor or coil winding vs wound as in bullet wound, entirely different pronunciation. Some years back, I read a treatise that English isn't a language, it's a weapon designed to create madness. As a native American and am also fluent in UK English, I completely agree.
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It looks like there's some HF noise in the lab. Judging by the spikes on the oscilloscope, I suspect either light switching spikes or more likely cellular phone interference nearby, around a few meters away. Also looks like the 'scope leads might be near a transformer or they're growing resistive in the shielding, as there is a LF ripple apparent. You covered etching of the foil nicely, many classes on electrolytic capacitors omit that critical fact. I'd probably have gone lightly into inductance in capacitors, especially electrolytic capacitors, just to be thorough on design considerations and a small ceramic or mylar cap to counter ringing. Haven't worked in electronic circuit design in decades, nearly forgot about frozen electrolyte. Good to remember if I ever design something for arctic, high altitude or space usage. Unlikely, but in my life, the unlikely occurs far too frequently. Back when I was working as an electronics technician, I worked on everything from vacuum tube analog, germanium transistor analog, silicon transistor analog, discrete IC analog, VLSI analog and digital circuits. I work in IT now, but still remember my electronic theory well, which has saved my bacon on more than a few occasions. Knowledge is power! And equally important, useful.
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@brainndamage a quarter watt is a quarter watt, it should dissipate the heat without consideration of the leads themselves, which could be of pretty much any length.
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@jagmarc and ceramic spacers to enforce that separation. If memory serves, the iron based leads were what, about 1/4 the thermal conductivity of the copper? I think that was around the number. I remember the first time I saw iron lead resistors, had no clue why the solder kept melting on the board and the board starting to overheat, then one of the older guys showing me. I think that was about a month after electrons were invented. ;)
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There's value with temperature, but there's also noise. Cheap and seconds are going to be noisier. Not too big a deal in a logic circuit, but anything with significant gain and that noise could overwhelm signal.
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The laugh is, years ago when I started out in electronics, 20% tolerance wasn't uncommon, 1% was wire wound and eventually, metal film. Of course, the circuits are far more reliable now, due to much better tolerance and materials.
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@jagmarc usually, true. But, there were some applications where tolerance was a big deal, namely when operating in the nonlinear part of the curve. One could get a hell of a lot more gain in such portions of the curve, at a cost of more problematic selection of tube or transistor. Although, solid state device performance stabilized to much better tolerances over time. Not so much with vacuum tubes, due to their very nature and methods of operation. But, in the majority of applications, you're spot on. Most devices were operated in the linear part of their performance curve. More stable and far less heartburn than requiring matched pair in push-pull operation.
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@brainndamage true. I also remember some applications where the resistor was designed to run hot and iron leads with ceramic standoffs were required. Discussing those in another thread here. In one case, it was due to selection of a lower wattage carbon resistor for noise reasons, the higher wattage being noisier. Engineering is very much about tradeoffs.
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@jagmarc yeah, got my NASA soldering certificate back in 1980. So, I'm familiar with the general specs, if not a more current price per component. So many failure modes, it astounds me that the Voyager probes still retain any operational capacity today! Then, we get politicians griping about the expense of components and why we can't go COTS. Sure, get them from Battlestars R Us. :/
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Probably some crud on the leads themselves from when they were made or packaged.
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@brainndamage typically, normal flux. But I'm talking about the core, most still had tinning. Although, I've had to use either alcohol or even acetone to clean adhesive from leads before. Don't know if the adhesive simply degraded or just some weird off brand.
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@jagmarc match pair amplifiers were matched either at the factory or one matched them oneself with higher end test rigs to ensure the beta gain matched. Rarer circuits though, as most circuits used amplifiers in their linear part of the curve, so pretty much anything of that version matched, be it a vacuum tube or transistor. Although, in early integrated circuits, the biasing was still external and even today, operational amplifiers still get their feedback set via external resistors. I remember making a doorbell out of an old 741 op amp that was set just shy of oscillation so that it'd ring when triggered.
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@d614gakadoug9 precision and tempco that tight, mil aero or space applications?
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@d614gakadoug9 yeah, that could either turn expensive or expensively entertaining, rather than enlightening. Entertaining, if it's only the reference legs on a wheatstone bridge wandering in value randomly. Expensive, if it's measuring production or providing a reference bias... Well, unless one's goal is to, rather than turn out a flat and true product, produce a funhouse mirror. ;) Sounds only minor, until one considers the difference between a non-precision automotive bearing and a high speed turbine bearing. Then, wobble shakes things apart and lateral runout can turn a stator into fragments as the rotor tries to convince it to joint it in its motion. Did you ever look at what's required for use in space? That's even tighter, due to thermal, oxidative effects of the rarefied upper atmosphere and radiation effects, to name a few variables (not to mention no free oxygen being permitted in anything, especially insulators). Worked briefly with that, boy, but the requirements were demanding, exacting and absolutely necessary. Or, in the case of the Mars rovers, one EE asked, "Do dust devils possess an electrostatic charge?". Everyone he asked didn't think so, but couldn't find any reference. So, he made a trip to the desert with some instruments and was horrified to find tens of kilovolts accumulating within dust devils. That necessitated a complete review of rover circuitry. The finding being, as initially designed, the rovers would've failed catastrophically on first contact with a dust devil. Now, they're optical cleaning events.
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