Will this mean electronic waste ends up in other countries rather than China? If so, will it be recycled for parts or end up in landfill?
As of now India is getting criticized for the massive imports of electronic waste causing ill health to many but like some other countries in the region there are some very poor people who need to feed themselves but India isn't the biggest importer Africa has large imports so you are right --it will end up in other countries where poverty is high without a lot of welfare support still being taken apart.
China,s decision in its new "rise to power " for the masses is a bit political as well.
China,s decision in its new "rise to power " for the masses is a bit political as well.
The trouble is with ebay while you can filter out Chinese sellers quite a lot of UK sellers use cheap Chinese components.
I bought some irf240 off ebay and they worked fine at least for 10 minutes.
I unplugged my soldering iron and the glitch down the mains blew up the irfp240's. SO bought in some irfp240's from RS Components and they are still going a year on despite many unpluggings of mains items.
I can only guess the fake items had a low breakdown voltage and the spike on the supply killed them.
I bought some irf240 off ebay and they worked fine at least for 10 minutes.
I unplugged my soldering iron and the glitch down the mains blew up the irfp240's. SO bought in some irfp240's from RS Components and they are still going a year on despite many unpluggings of mains items.
I can only guess the fake items had a low breakdown voltage and the spike on the supply killed them.
I couldn't believe the audacity of this "born again " seller who is now boasting about how he made a mint selling fakes and "on the road to Damascus " had a "Revelation " and is now selling "quality " products .
He is so proud of his work that he has posted his own "bible " on how to get started ---not a hint of shame just arrogance-
How You Can Make Big Money Importing From China - The Rise and Fall of My Empire...
Please do not copy him !--- but it gives you an idea of the methods used.
He is so proud of his work that he has posted his own "bible " on how to get started ---not a hint of shame just arrogance-
How You Can Make Big Money Importing From China - The Rise and Fall of My Empire...
Please do not copy him !--- but it gives you an idea of the methods used.
You realize, that by you posting his URL on a reputable site (DIYAudio), you have greatly increased his search ranking.
That did not occur to me but I knew somebody wouldn't be happy with me giving the details on how scammers operate which is ---EXACTLY---what this thread is all about so I took the intelligent action by showing some others who obviously don't know the dangers of online ordering from the big business websites and who think -Amazon-eBay-AliBaba-- etc -etc are beyond reproach that at this very moment are being taken to court by governments/individuals /US States etc for the devious and criminal actions of sellers on their websites .
If you keep up to date with world news the excuse ---oh ! but we are only a platform --no longer holds legal water.
So all in all censoring or hiding the truth may be the fashion on many websites but I hope DIY Audio sees the bigger picture as at the end of the day this might stop or make some youngguy think twice about ordering up that 5 cents BJT when a genuine one sells for $5.
If you keep up to date with world news the excuse ---oh ! but we are only a platform --no longer holds legal water.
So all in all censoring or hiding the truth may be the fashion on many websites but I hope DIY Audio sees the bigger picture as at the end of the day this might stop or make some youngguy think twice about ordering up that 5 cents BJT when a genuine one sells for $5.
Have realistic expectations. The Customer service at Ali lacks the technical background or time resource to investigate such claims. Otoh, you can ship any goods you didn't like back within 2 weeks after receiving without any explanations. Of course at your expense and definitely with tracking. A refund then follows.
Here's where Amazon has a major advantage. Part of their "A-to-z Guarantee" policy:
And Paypal has (used to anyway) a return reimbursement feature as well. Never had it cost anything close to the purchase price when I did use it, so you may not have any luck in going that route on these purchases where your shipping fees are ridiculous. Also limited to a certain number of uses per year, but, I've used that a handful of times in the past to eat those charges to return clothing or something.
It’s been years….
I figured these AD797AN 8 pin Dip parts had been around for 20 years, or more, likely these parts were from 10 to 15 years back and never got used, now surplus. This probably happened in 2018 or 2017, I just checked some of my 30 DIP’s on my Fluke - pin 8 seems over 20 megohms to any other pin; pin 1-4, and pin 4-5, measures ~1,000 ohms or so (+200/-50 ohms) so yup, my ADELEPARTS2010 AD797AN’s from 3 or 4 years back are cheap, cheap LM741’s (luckily I never used them).
Over the past 3 years, I also bought OPA-2604’s DIP’s from: ALICE1101983; LME49720’s: HUAYI-COMPONENTS; OPA1611, OPA1612, OPA1641, and OPA1642’s from: TEVATRONIX, and LME49710’s in DIP, AD797ANZ’s in DIP from ???
So… anyone with a Fluke or similar meter with 10 megohm input, on a 0 to 20 megohm (and/or diode) scale, can we get a list of pin to pin readouts on KNOWN REAL chips - those that came from: Digikey, Newark, Farnell, Arrow Electronics, or were shipped direct from the manufacturer, and came in Level 2 hermetically sealed packaging, along with signed certificates of compliance!!!
So what should the reading be on A REAL AD797AN pins 1-4, 1-5, 6-8? Same for the other singles… OPA1611’s, OPA1641’s, LME49710’s. I appreciate this thread, and all the great techs, who contributed so far, and thank you all for your time and efforts!
Thanks,
Steven
I figured these AD797AN 8 pin Dip parts had been around for 20 years, or more, likely these parts were from 10 to 15 years back and never got used, now surplus. This probably happened in 2018 or 2017, I just checked some of my 30 DIP’s on my Fluke - pin 8 seems over 20 megohms to any other pin; pin 1-4, and pin 4-5, measures ~1,000 ohms or so (+200/-50 ohms) so yup, my ADELEPARTS2010 AD797AN’s from 3 or 4 years back are cheap, cheap LM741’s (luckily I never used them).
Over the past 3 years, I also bought OPA-2604’s DIP’s from: ALICE1101983; LME49720’s: HUAYI-COMPONENTS; OPA1611, OPA1612, OPA1641, and OPA1642’s from: TEVATRONIX, and LME49710’s in DIP, AD797ANZ’s in DIP from ???
So… anyone with a Fluke or similar meter with 10 megohm input, on a 0 to 20 megohm (and/or diode) scale, can we get a list of pin to pin readouts on KNOWN REAL chips - those that came from: Digikey, Newark, Farnell, Arrow Electronics, or were shipped direct from the manufacturer, and came in Level 2 hermetically sealed packaging, along with signed certificates of compliance!!!
So what should the reading be on A REAL AD797AN pins 1-4, 1-5, 6-8? Same for the other singles… OPA1611’s, OPA1641’s, LME49710’s. I appreciate this thread, and all the great techs, who contributed so far, and thank you all for your time and efforts!
Thanks,
Steven
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Greetings everyone,
I must confess, I couldn't resist the temptation to acquire the ceramic DIP8 SQ version of the AD797 Op. Amp for merely ~$4-5, especially when faced with a seller on Ali-express boasting 1001 positive reviews, claiming it's "exactly what is being sold" and so forth. Indeed, two op-amps arrived, impeccably polished in their ceramic SQ packaging, with engravings that appeared as original, complete with the Philippines or Malaysia listed as the country of manufacture on the back, along with all the minor details that match some of my old and guaranteed original AQ and SQ versions of the AD846/843, etc.
Upon initial listening, the OP. Amp "sounded OK" until I began testing its noise level and response speed, i.e., the rise and fall times of a square signal (Tr/Tf). Perhaps the Rise/Fall time might have misled me (the original is 20V/us) with about ~12-15V/us, but the noise level indicated it was a decidedly mediocre op-amp.
My suspicions of it being counterfeit were aroused since it was supposed to be identical or superior to the LT1028, OPA1611, and OPA1612, yet it fell between the NE5532 and TL072. Through measuring characteristics such as resistance, etc., I deduced it resembled something along the lines of the LF356/411. This assumption remained until, during the soldering of the pins, I accidentally sprayed cooling spray (intended for cleaning) on the hot ceramic casing, causing it to crack open and reveal the IC's die.
Now, after a couple of years, having finally acquired a 5MP CCD microscopic camera and a better (though still juvenile) AOMEKIE 20x stereo microscope, I can share with you the appearance of the IC Die, which by design, closely resembles (99%) the LF356/357, with the only question being the exact model.
Hence, we can conclude that the mystery is solved depending on the response speed of the Op.amp you've purchased; you've gotten either an LF355, LF356, or LF357, the question remains whether you bought the metal canister TO-CAN and ceramic, or if you opted for the plastic DIP, then you've indeed incurred a loss
In any case, there's no trace of the 1nV/sqrHz, instead expect 12..20nV/sqrHz, which is up to 20 times higher, equating to +26dB for a higher noise threshold. Also, forget about the GBW of 110MHz since the LF356/357 equivalent has a GBW around 5 to 20MHz.
It was an apparent scam that I, too, fell for, so if you see any comment of mine on the seller's website, please disregard it as it cannot be withdrawn retrospectively.
Attached are the spectral image with a 50 Ohm terminated input at Av1 and the appearance of the IC Die.
Best regards,
Dr. Jovan Ivković
I must confess, I couldn't resist the temptation to acquire the ceramic DIP8 SQ version of the AD797 Op. Amp for merely ~$4-5, especially when faced with a seller on Ali-express boasting 1001 positive reviews, claiming it's "exactly what is being sold" and so forth. Indeed, two op-amps arrived, impeccably polished in their ceramic SQ packaging, with engravings that appeared as original, complete with the Philippines or Malaysia listed as the country of manufacture on the back, along with all the minor details that match some of my old and guaranteed original AQ and SQ versions of the AD846/843, etc.
Upon initial listening, the OP. Amp "sounded OK" until I began testing its noise level and response speed, i.e., the rise and fall times of a square signal (Tr/Tf). Perhaps the Rise/Fall time might have misled me (the original is 20V/us) with about ~12-15V/us, but the noise level indicated it was a decidedly mediocre op-amp.
My suspicions of it being counterfeit were aroused since it was supposed to be identical or superior to the LT1028, OPA1611, and OPA1612, yet it fell between the NE5532 and TL072. Through measuring characteristics such as resistance, etc., I deduced it resembled something along the lines of the LF356/411. This assumption remained until, during the soldering of the pins, I accidentally sprayed cooling spray (intended for cleaning) on the hot ceramic casing, causing it to crack open and reveal the IC's die.
Now, after a couple of years, having finally acquired a 5MP CCD microscopic camera and a better (though still juvenile) AOMEKIE 20x stereo microscope, I can share with you the appearance of the IC Die, which by design, closely resembles (99%) the LF356/357, with the only question being the exact model.
Hence, we can conclude that the mystery is solved depending on the response speed of the Op.amp you've purchased; you've gotten either an LF355, LF356, or LF357, the question remains whether you bought the metal canister TO-CAN and ceramic, or if you opted for the plastic DIP, then you've indeed incurred a loss
In any case, there's no trace of the 1nV/sqrHz, instead expect 12..20nV/sqrHz, which is up to 20 times higher, equating to +26dB for a higher noise threshold. Also, forget about the GBW of 110MHz since the LF356/357 equivalent has a GBW around 5 to 20MHz.
It was an apparent scam that I, too, fell for, so if you see any comment of mine on the seller's website, please disregard it as it cannot be withdrawn retrospectively.
Attached are the spectral image with a 50 Ohm terminated input at Av1 and the appearance of the IC Die.
Best regards,
Dr. Jovan Ivković
Attachments
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Nice posting.
I was looking at the cost of a AD797 on Mouser yesterday, it was over $20CDN
Personally I would never buy anything using AliExpress, from the get go it is just to cheesy for me. Some eBay sellers from China are questionable as well, some are known bad actors, it’s buyer beware especially on items that sound to good to be true. I wish eBay would deal with them in a proper manner.
A design that is critical enough to specify a AD797, goes without saying, buy from an authorized distributor
I was looking at the cost of a AD797 on Mouser yesterday, it was over $20CDN
Personally I would never buy anything using AliExpress, from the get go it is just to cheesy for me. Some eBay sellers from China are questionable as well, some are known bad actors, it’s buyer beware especially on items that sound to good to be true. I wish eBay would deal with them in a proper manner.
A design that is critical enough to specify a AD797, goes without saying, buy from an authorized distributor