are there counterfeit power rf transistors

[bd139]

It goes right down to 2n3904's unfortunately. I had some PNP ones a while back.

[CJay]

I think power RF transistors are the most counterfeited of them all.  The TO-92 (small signal) and TO-220 formats in particular if the supplier is not reputable can be any crap, and many times you'll drive yourself nuts because the fake thing has the same junctions as the original and it could possibly half work for some random time.

Other packages may also be counterfeited, but most of the time they tried to build it and they may be working fakes or quality control rejections. Or it may just be the part code made to spec by some proper factory. Be very aware with any final power transistor for a transceiver, as they are on high demand for repair work at the lowest price.

It's not even as sophisticated as that, they seem to just take any old TO-220, grind the top off and add a new marking, it's out and out fraud.

It's not even the small quantity sellers on eBay, most of them wouldn't know a transistor from a banana and have probably never even seen the parts they sell, it's their suppliers.