We should probably discuss this subject here maybe?
https://forum.allaboutcircuits.com/threads/3-important-problems-to-resolve.172235/page-3
to keep the discussions clean, each on their own subject?
On this discussion I will concentrate further on opams and there on the other subject with the mosfets and lm3914 and the switching circuit.
Thank you.

 

The 7000 and the 500 series were really nice. The 5000 series added IEEE-488. You could build your own modules, key them and make the interconnects on the backplane. You could build a IEEE-488 interfacable distortion analyzer that way on a 5000 mainframe.

Even with Tektronix, there are glitches. People have made new sampling heads or or have to have a bad one Someone even made a replacement Hybrid IC on a PCB, but it's not 100% as functional. Tek instruments suffer from the tantalum capacitor plague.

Danahar corp changed them (Fluke, Tek and Keithley) for the worse.

 

Tek instruments suffer from the tantalum capacitor plague.

Tell me more about this plague.

 

Tell me more about this plague.

They tend to fail short. That's a problem if they're across the power supply for decoupling.

 

Tell me more about this plague.

https://en.wikipedia.org/wiki/Capacitor_plague

 

Oh, wow that was a very big deal. I was not aware at all of this disaster. Fantastic history page.
Thank you for the very good information about it.
Actually, I am PRO Evident failure in components and AGAINST subtle or invisible failure in components.
I want to see the thing is BLACK, full of fumes and ashes, to quickly identify the bastard. Ofcourse, not affecting the other components around it.
I was fantasying some time ago, about thermochromic paint, that can be added on ALL electronic components. That paint will change its color with heat. A simple longitudinal line, will suffice as indicator. Im not at all expert on these substances but it would be very interesting to see a range of colors, and not only dark or red or whatever monochromatic pigment is composed of.
Nice dreams,right? It will never happen. :]

 

Then there is the stuffing of smaller e.g. 100 uF capacitors in bigger cans say marked 1000 uF and charging for the bigger size.

 

Fake Components

https://sound-au.com/fake/counterfeit-p4.htm
https://sound-au.com/counterfeit.htm

 

Sellers on ebay, AliExpress, Banggood and other websites over there will do any kind of cheating to steal your money.
Here is part of a video about a fake ebay battery:

 

Fake external hard drive

 

I am after solutions, personally. What is to be done to "avoid" fakes, in your opinion? Im sure you found several solutions for how long you are dealing with them. Right?
I understand, and I know there are such individuals who are selling fake components, machines and important stuff. I am always afraid of getting a couple of rocks instead of the product i ordered, and i am always precocious. But what can I do? Remain precocious all the time? I get tired and stressed, very quickly, and everybody knows it. Not buying from a market because 1 stupid adolescent is having fun on my money? The market itself has they rules themselves and you can report the package as having fake or empty or incomplete content, using any means, like pictures or movies stuffed in the email to them. I did it numerous times, not for fake products but for incomplete ones - i ordered once 10pcs and i got 1 (for the price of 10 and with all its pins bent diagonally, and packaged in a simple plastic bag). I got the real 10pcs back after all my complaints (another 3 months) , after i reported the "mistake" and now im "happy", it is not that nice to stay on guard all the time. Its stressful until the package arrive, and that stress spans over 2-4months, until the package arrive. Not fun but is the "modern" way. And we must pay not only with money but with stress too. Stress these days is another payment method. In other words, if you dont show you are stressed, then you are happy and is not correct, socially, and they(society) must make you feel bad and shitty. And they succeed in most of the cases. Its a MEAN mentality from which some people get some pleasure.
There is also market espionage. Im not sure if from the same market voluntarily, as an experiment or a lesson, or from other online markets to each other. I learned there are more online markets, others than ebay. Ebay is the biggest and oldest (probably). I didnt check but is what i remember. I do use aliexpress as a secondary market choice, but they have some extremly expensive prices, sometimes even double as you can get from ebay. I look there sometimes. Sometimes i stumble over some incredible offers from aliexpress that beat the hell all the cheapest prices on ebay, but unfortunately, when the offer expire, the price go up to double, or triple again. I catch 1 offer like that. Also on aliexpress I can get some "rare" components that on ebay are absolutely "extinct"/gone. For example the resistor 75 values pack (or greater) (Full Range of Values) the 1/4 W 5% old carbon resistors (long leads) , are extinct from ebay. Or at least for a good long period (years), exactly when i was looking for them, they were not to be found on ebay. But i did find them on aliexpress at a higher price(somewhat acceptable) . And i did buy them from there, but with my hearth ripped in half. My hearth was already ripped in half from the blue 145 values resistor pack, 1/4W 1% new metal film resistors. I like that they are qualitative from the 1% part, but... i really like the old CLEAR CODED carbon resistors. The blue ones are just impossible to read, 1 because the contrast is very bad between colors and 2 because the very different coloring system they have for 5bands, than the classic easy to remember coloring 4bands and 3 because the lines are absolutly equaly distanced and you will have no idea where is the head and where is the tail of the color bands reading. And everyone bought the new ones !!!! And everybody are happy. Well, I am not ! Yes, they are good for industrial production, but absolutely horrible for experimenting, like i do. At least is how i see it. Do not shoot my subjective opinion !!! So in conclusion, I had to buy the old carbon types because their ease of coding/reading and also good contrast between colors. You can keep an arm long distance from your eye and read its value with certainty. Try it with the blue ones and see how many swears you make from only 5cm distance from your eyes. I think people are getting stupid by inventing unnecessary new ways for the working old ways.
But back to your original problem: - What is to be done to "avoid" fakes, in your opinion? You know me, I like solutions, and the only solutions that i can think of, is to either be smart and very energetic when you are served with the fakes ones, reporting the shit out of it to anyone you can on internet, and believe me there are agencies that they have nothing better to do than resolve cases like these, or just simply "suck it" as i suck it myself and many others, (until I started to be more impulsive).
Its how i think of this problem, from my little white square in this very large world of 'bizniz'.

 

What is to be done to "avoid" fakes, in your opinion?

Buy from reputable sources. eBay, Amazon, Ali Express, Banggood, and the like aren't reputable because the platforms don't vette sellers and haven't made any significant effort to reduce the sale of counterfeit parts. Feedback ratings aren't foolproof because sellers can fake them.

 

Buy from reputable sources.
Feedback ratings aren't foolproof because sellers can fake them.

I agree if i would have money!! The reputable sources are 10 to 50 times more expensive than ebay, or the other common markets. But we live in capitalism and we must endure and sacrifice, search and get the best to our pockets (not needs). This is the progress of capitalism and you or I cant do anything since from now on, is written in stone as this is the new way.
I agree, I have some sellers on ebay that switched their names a couple of times. And I learned from the begining, to not trust that much their stars, because is easy to buy that "reputation", which is usually the case - everywhere, not only on ebay. Even on facebook and social media. Everywhere is not gain but bought. And is pretty obvious how over night they got 10k likes - come on. Again, capitalism rules, right? Hahaha.

 

You tell me which is the better buy, an item for $1 that does not work or an item for $4 that works.

 

I agree if i would have money!! The reputable sources are 10 to 50 times more expensive than ebay,

We have to save for what we want and spend that money wisely.

To save money on semiconductors, I generally buy enough to get a price break.

Jameco.com sells 2N7000 for $0.35 for quantity 1, but less than a third of that for quantity 100:


Tayda sells them for $0.09 each and Jameco will price match from legitimate verifiable sources; so you could get 10 for $0.90 as long as it's not below their cost.

 

Electronic parts are not expensive. If you are educated and have a good job then money grows on trees.
I am 75 years old and are retired. My government pays me a pension so I do not work and I simply pickup the money.
You order fake or defective parts from China and wait one month for delivery.
I buy genuine inexpensive parts from Digikey and if I order before 8;00PM then the parts are delivered to me the next morning. Digikey (in USA) is not in my country (Canada).

 

Even for non-semiconductors, I might find me buying 500 or 1000 for a stupid plastic part.

hardware is like crazy. I want some 4-40 Aluminum Threadserts. 4-40 is rare. I have the tools for #6 to 1/4 and 4 and 5 mm.
they don't make a mandrel for 4-40. I have to buy a manual tool. No machine shop so I can't customize say a 10-32 mandrel.
How many do I have to buy 100 at like $35.00.

I won't find these at my local hardware store.

 

Trust me when i tell you how things are for me. Money are a very sensible subject for me, so please dont mention them. Just understand i must orient myself for the cheapest and not for other criteria as people with money do. I must adapt and concentrate on what I can do with the limit I have as you probably do on your side. We all adapt and survive in this life. Right? Thank you for your understanding. Im sure you are very intelligent persons and understand this little inconvenient I have. Im not perfect.
Right now I am doing the design for the light switch... that will use the lm3914 and the sensing wire circuit and the switch circuit with the electromagnets ...and i probably bend the stick too much but i will insert a motor in it... I am telling you, it will be Glorious ! You will see. And i am very sure you will like it as I am. So glorious... uuuh.

 

Money are a very sensible subject for me, so please dont mention them. Just understand i must orient myself for the cheapest and not for other criteria as people with money do.

You can salvage components from discarded electronics and save for what you need. Don't think you need to buy parts from disreputable sources just because you don't have discretionary funds. Save for what you need.

 

I bought an assortment of 480 1/4W 5% carbon film resistors with clear color coding from a local electronics parts store.
They are Velleman name brand and they were inexpensive.