2SK170 original or fake

Status
Not open for further replies.
I followed the link to Xzen as you suggested and measured the Yfs and confirmed that both the 2SK170's and 2SJ74's I bought on Ebay are fake. With a input of .05 volts the output across the 100 ohm resistor was any where from .156 to .239 volts on the real FETs and .028 to .035 on the fake ones. The fake FET s have an off center and I'll defined mold mark on the top where as the real ones have a centered and sharp defined mark. Lettering is sharp and clear on the real FETs where the fake ones have I'll defined lettering. The fake 2sk170's stick to a magnet. Thanks for the link to zen-audio.com
 

Attachments

  • 20181210_225242.jpg
    20181210_225242.jpg
    314.1 KB · Views: 485
  • 20181210_225745.jpg
    20181210_225745.jpg
    866.2 KB · Views: 478
  • 20181210_225949.jpg
    20181210_225949.jpg
    622.8 KB · Views: 458
  • 20181210_230611.jpg
    20181210_230611.jpg
    802.1 KB · Views: 477
Status
Not open for further replies.