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Author Topic: What’s inside a counterfeit device?  (Read 1821 times)
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WA2SQQ
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« on: January 23, 2024, 09:32:30 AM »

We have all purchased parts from eBay, and other similar places only to discover that they might be counterfeit. I found this very interesting video where some of these counterfeit devices have been opened up to reveal what’s really inside. It really motivates you to purchase products from reputable sources, but can we really trust them?

https://youtu.be/NSgqYLLPUSs?feature=shared
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W1RKW
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« Reply #1 on: January 23, 2024, 04:00:12 PM »

experienced this at my work place. we have a test system for screening completed assemblies.  The test system detected oscillations from the bogus op-amps. we sent the suspect parts out for analysis and just like this Youtube video, the dies were different.  Long story short, the vendor who was peddling this junk ended up in jail. The incident ended up on 60 Minutes.
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Bob
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WTF-OVER in 7 land Dennis
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« Reply #2 on: January 23, 2024, 11:32:55 PM »

For all sorts of electronic parts, a "smokin' deal" is usually a bunch of fakes.

NOS from a known source is $ well spent. 

I've had good luck with Circuit Specialists (they are a direct importer) in Tempe, AZ and Tri-Tek in Mesa, AZ.

73DG
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KD1SH
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« Reply #3 on: January 24, 2024, 11:59:39 AM »

   When I was working, the company was often faced with components nearing their sunset, and the purchasing department would resort to obtaining parts from questionable sources. In the R&D lab, I was often tasked with kludging up test rigs on my bench for verifying the functionality of these parts before turning them loose on the production floor.
   The bogus parts would pretty much always function, but with notable caveats: low-drop-out regulators would regulate, but the input/output voltage differential wouldn't quite meet the promised spec, or they'd start to inject "fuzz" into their outputs under load, and op-amps would amplify but break into oscillation at certain gain settings, or generate offsets that couldn't be compensated for.
   A friend of mine once ordered a batch of "gray market" 2SC1307's—common in 70's and 80's CB rigs—and they functioned poorly. I'm sure that at some frequency they worked fine, but they couldn't hack 27mhz. "Close" only counts in hand-grenades and horseshoes, as they say.
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KB5MD
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« Reply #4 on: January 25, 2024, 12:21:22 PM »

Maybe that’s the reason the single transistor bfo I built three times would never oscillate. 
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W7TFO
WTF-OVER in 7 land Dennis
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« Reply #5 on: January 25, 2024, 05:17:58 PM »

I remembered another local shop that has electronic components and does online orders:

Electronic Goldmine in Scottsdale.

They have a lot of good and occasional oddball stuff. Wink

73DG
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W1RKW
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« Reply #6 on: January 25, 2024, 05:27:39 PM »

to add to my post above, I remember some of the forensics that were recorded. Not only where the dies a dead give away after dissecting the component, little hints such as graphics on the body of the component where compared.  To the naked eye they looked identical. Under a microscope and side-by-side comparison, not so much. 
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Bob
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« Reply #7 on: March 04, 2024, 12:27:34 AM »

Made in China is a good clue, but they also DO make some nice things. So I use Digikey and Mouser, hoping they add an extra stage of filtration. If they don't have what I need, which is entirely possible, then I set off on my own, navigating treacherous waters. Ebay, Amazon, and small time US dealers are always suspect to me. This hobby of restoring old rigs seems to be wearing me down, just on account of this very question.
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