The gate should behave like a silicon diode to drain or source, conducting when ~0.6V positive of them
Originally Posted by Cyberkul View Post
And if I did measure correctly, the VGS (off) is positive, not negative as in the spec sheet.
UGS in negative
here are my curves:
https://www.diyaudio.com/forums/pas...ment-toshiba-2sk170-2sj74-33.html#post5800266
And if I did measure correctly, the VGS (off) is positive, not negative as in the spec sheet.
UGS in negative
here are my curves:
https://www.diyaudio.com/forums/pas...ment-toshiba-2sk170-2sj74-33.html#post5800266
If you are talking about my pictures, it is my personal stock of 2SK170. Pictures were taken by me.
You should report seller to Ebay and ask for full refund.
Thanks! Yes, I noticed that I misread the polarity after a while..
I tried to make a Vgs vs Id curve myself today. I think gm looks reasonable, about 28-33mS, depending on how high up on the curve I take the reading?
Not sure which values to use, but at least it is a high gain device.
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I showed him both your pictures, and the one with text. Do you mean that the picture alone should be enough to say that my transistors are fakes? Can I be sure that the Toshiba casings are always like this?
Based on the IDSS I can report the seller anyway, since the BL range 6-12mA was stated in the listing, and these are clearly about 15mA.
Yes, with my (very) limited experience, it looks ok compared to the datasheet, except for the IDSS, since this is the BL-version. Also, it doesn`t have the 2mm centered seam on top. More like 1mm seam offset to one side.
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I got a full refund from eBay for the transistors.
eBay seller punkydawgs (recommended by Nelson Pass) had some interesting information regarding these transistors. He said that in a bag of 200 1% or less would have a IDSS more than 12mA. Also, there have been production in other countries than Japan, and early versions that he could not say for sure are looking the same as on the pictures earlier in this thread. I think I use the refunded money for transistors from punkydawgs.
eBay seller punkydawgs (recommended by Nelson Pass) had some interesting information regarding these transistors. He said that in a bag of 200 1% or less would have a IDSS more than 12mA. Also, there have been production in other countries than Japan, and early versions that he could not say for sure are looking the same as on the pictures earlier in this thread. I think I use the refunded money for transistors from punkydawgs.
I've always had excellent service from John LaGrue (punkydawgs). I've bought tubes from him as well....
Seller Alweit pair matching is very accurate. He has GR grade pairs at fair prices. I used a Keithley 2231 programmable supply and certified factory calibrated Keithley 2110 voltmeter to check. All matches to within .05 mA from my measurements.
Do Alweit's have the stick '9', or the curved bottom '9'? (I'm beginning to think that Toshiba did indeed go from one to the other at some point.)
(And does anyone have a close-up of any of Nelson's parts?)
(And does anyone have a close-up of any of Nelson's parts?)
Both Fairchild and Motorola made the J112. ON Semi bought both of them. Which fab line did they keep?
Your lettering most closely matches the Fairchild lettering, but without the Fairchild 'F', and with a different font. You could see ON Semi just dropping the 'F' for a quick fix post-acquisition, but if they changed the font then it's harder to understand why they didn't add the ON Semi log (or at least re-centre the date-code).
A counterfeiter, on the other hand, might not have either the script-F or the circled-ON in their font. So the just left it off. Still, why in the world would you counterfeit a 38-cent part? You'd have to sell gazillions of them.
More questions than answers, I'm afraid.
Your lettering most closely matches the Fairchild lettering, but without the Fairchild 'F', and with a different font. You could see ON Semi just dropping the 'F' for a quick fix post-acquisition, but if they changed the font then it's harder to understand why they didn't add the ON Semi log (or at least re-centre the date-code).
A counterfeiter, on the other hand, might not have either the script-F or the circled-ON in their font. So the just left it off. Still, why in the world would you counterfeit a 38-cent part? You'd have to sell gazillions of them.
More questions than answers, I'm afraid.
Eaxactly the same J112 marking in this image
https://ae01.alicdn.com/kf/HTB1VjPraQWE3KVjSZSyq6xocXXay/20PCS-LOT-2SJ112-J112-112-TO-92.jpg
Aliexpress, so probably a copy
https://ae01.alicdn.com/kf/HTB1VjPraQWE3KVjSZSyq6xocXXay/20PCS-LOT-2SJ112-J112-112-TO-92.jpg
Aliexpress, so probably a copy