How know when LM357 is original?...

[Rodelio]

Yes, it's true. Some of this ic's are brand new and no tested yet. The lm356, lm308 and lf353 in the picture has been tested and it work's very well.
As you say, maybe the only way to recognice the original one, is testing it on the final circuit.

[kt315]

eddy did good tester. ali selling fake tl072 really remarked lm358. so tester measures the speed and indicates by color by leds it is good or not.

http://www.eddy.com.ua/archives/229

[ionut_mtb]

https://ibb.co/zS2XpFD
https://ibb.co/pxKfLCd



i?m in doubt... what do you think about this?

[Rodelio]

They could be made in the same week an day, or be made by chenise clon factory. I don, see a diference between any of them.

[dbanner]

The genuine LF357N is jfet op amp.
The really bad fakers don't necessarily know this, they just paint over any old 8 pin chip. Should be easy to check with meter if it's a jfet op amp or not. If it is, then chances are that it's the real deal. Also the genuine original stock ones have the stripe across the top. for some reason, which I can't figure out, the fakers don't like putting stripes on their chips.
I have an original LF357N which has the stripe. All the other LF357N chips I have ever bought without the stripe turned out to be FAKE.
My original LF357N has seen better days. It has two broken legs which I kept resoldering every time I needed to test a circuit.
I then found the NTE937M using the NTE cross reference, luckily there was a local supplier. It worked well, so I retired my LF357N.
If you have a signature curve tracer, then its easy to compare op amp and comparator chips at a glance, otherwise you stick it in a working circuit, and check it's performance.

[Rodelio]

Thank's dbanner. Good information. I alwayd trust in the operatinal Ic's whith the stripes on the top. All whith this caracteristiques in my stock worrk veri aood "lucky possibi". I think that the four numbers on the chip indicate the year and week they are made. Like in the ATmega chip...

[Rodelio]

Sorry for my redaction. I use my smarth phone and whith mi "little" fingers it's somethig like a monkey in a keyboard.

[kt315]

real presentation gives just the chip itself. so this article How "to open" a micro https://habr.com/ru/company/zeptobars/blog/157917/
sorry i do not know similar info in english zine.

[Rodelio]

Wow, what a great view of the inside of the chips.
I saw in your #17 the ic tester. I will like build it. I try to download the code and the documentation but i must be register on there. Will you post in here?...

[kt315]

add Eddy in friends and you will in contact with him. https://www.facebook.com/eddy.com.ua/
his info is open and i do not see why you have to register.

[kt315]

yes, now i see no access to files. Eddy had personal site with all opened. now it is not accessable. he losed off the password.
must tell you the long story again. Eddy was arrested by putinsky neofaschists on territory of eastern Ukrainia. then he was in jail two years.
he was free on exchange of prisoners. certainly he could not been back in Lugansk city. you have to know that on territory of Ukrainia going the war and this is REAL WAR.
not what you see in your tvzombibox.

https://www.youtube.com/watch?v=rlVl4acFU6s
https://www.youtube.com/watch?v=VvvU98WW3CE

Eddy does not still have access to his home and his family.

[Mahally]

When products offered cheaper than to its original price. Think twice.

[Rodelio]

Hi kt315, i'm already send mi messange to eddy. I see his profile and seems to be a wise man. I suggest him something whith arduino and the ATmega328-p for the same objetive. The only thing left is to wait. Thak's kt315 .

[Rodelio]

Ok. When i write my last reply to you "5 minutes ago" i don't check the reply. Jus i write an send "no good" I see what' goin on with eddy rihgt now. I'm so sorry about hem. I take your advice. Thanks again kt 315. Regards.

[kt315]

Eduard is on Kyiv city and i hope he is ok. also he is registered in the forum and i think he is able to answer. but if you know
xUSSR people do not speak in english good. this is main problem why you see here just one kt315 while there is the army
of very advanced in electronics folks.