Counterfeit Parts

Some of you may have already encountered this problem, but the issue of counterfeit parts is growing. My day job is in industrial repairs. We have to source a lot of obsolete parts, and several times have found parts to be counterfeit, usually from China. Recently, I have been working on a few personal projects (old noise generator designs), using MPF102 JFETs. I kept getting strange results and then pulled my JFETs to put in my little transistor tester. It said they were NPNs! I put one of them on a curve tracer, and it definitely was NOT any JFET! These came from Amazon, who were kind enough to refund the purchase, but I made sure they addressed this with the seller. So, now I'm trying a number of other JFETs. Does anyone know if the MPF102 had any special small signal characteristics that made it so special?

Early JFETS such as the MPF102 had such a wide spread of characteristics that there was definitely nothing "special" about them.

Seems logical. I guess there weren't many alternatives, so a lot of early gear and designs had those JFETS -- it was all that was available at the time! I've ordered J113s, which are readily available from Mouser, and much more affordable!

I mainly wanted to alert folks to the parts counterfeiting!