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2SC3503E & KSA1381ESTU Group Buy

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#182
brian92fs said:
Question for those in the GB:
If I do manage to find SA1381E from a secondary source of unknown reliability, what would make you feel comfortable that they are legit?

Other than a visual inspection, sending them out for testing is likely too expensive. So, I am thinking of testing a sample from each bag. Something like this.

The easy testing would be:
  1. Test for breakdown voltage (using a eBay tester like this)
  2. Test for Gain on a Mega328
If they passes these, we'd probably need something more to verify
  1. Curve trace (on something like a Diligent Analog Discovery). SC3503 & SA1381 has a curve with a quasi-saturation region which should be easy to spot.
  2. Higher current load testing than the Mega328 or curve tracer is not capable of. Maybe a breadboard circuit at 10V - 20V Vce and 10mA or 20mA? Verify that the gain is good at a higher current and they don't fry.
These often come in bags of 200 pieces. Maybe test 2 from each bag? That would be 50 to 60 tests which would take some time to get through.

Thoughts?
Click to expand...
For me no, sorry. As I said, I appreciate everything you have done but I (we) signed up for something else, so no secondary source of unknown reliability for me.
 
#183
My KEC parts arrived from Profusion. I tested a good size sample, and quite happy with it. The gain is 135 typical for both KEC3503 and KEC1381. By contrast, the ON versions test 90 for KSC3503 and 139 for KSA1381, typical.
 

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#187
I have received two quotes for KSA1381E from secondary sources. This is for 6,000 pieces (more than the current GB to cover additional interest)
  • Worldway Electronics: $1.11 / each + shipping
  • Lingto Electronics: $0.92 / each + shipping
I have a few other emails out that have not replied yet.

I also reached out to Advanced Component Testing for a quote on authenticity testing. It comes out to around $0.15 / each for AS6081 Level A testing. This testing is specified as:
  • All devices
    • Documentation and Packaging Inspection
    • External Visual Inspection
  • Sampling of devices
    • External Visual Inspection 40X (2% of population)
    • External Detail Dimensional (2% of population)
    • X-Ray Inspection (0.75% of population)
    • Lead Finish Evaluation (XRF) (0.05% of population)
    • Remarking and Resurfacing Detection (0.05% of population)
    • Delid / Decapsulation Internal Analysis (0.05% of population)

If the KEC devices were not available, this might be work pursuing. But with KEC as an in-production alternative, it seems to me like this path is too expensive at this time.

Any other opinions?
 
#197
Seems like we are late or getting pushed aside on all these requests. Hoping that MOER will have some luck with tacticalic.

Brian, for the people that have paid for both 3503/1381 transistor types, but have not had any delivered due to waiting for the 1381, have you considered selling off / swapping the 3503's that were purchased and replacing them with the KEC 3503/1381 types from Profusion ? This maybe a viable work around as, who knows how business's operate these days, maybe KEC might swap your sc3503 for theirs and they sell the sc3503 to some other business.
Just food for thought, I can wait for the set's of new stock at Profusion (as quoted by Transistorlegacy), and even pay more for shipping, as long as I know we have an order that is not going ro be bumped.
MM
 
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