You can tell buy Toshiba's if you can afford them so Mr. North would not need people to send him transistors. All of the previous Hg, HG, H, PP, RFT, DEI, etc...have been made by the same people in China. Even the current latest and greatest from them are not direct copies of the part number they print on them.Each companies not only has their own design and materials make up but they have unique machinery that they have designed and built themselves to build their transistors. Dies are grown and each company has their own crystal growing system. You do not just "copy" a transistor it is not something simple like casting pistons in your garage or forging your own knife in your back yard. HG still is not able to make a transistor as good as Toshiba and Motorola did anyone that tells you they do is either ignorant or a liar take your pick. Best if you can license a companies design or buy their surplus equipment as they shut down plants and such!So again rumor has it that some years ago as the toshiba supply was drying up some builders started sending hg samples of different rf transistors for hg to use to advance their technologies. They continue to receive feedback from some builders which helps them make a better product.
Its taking time but they are getting better.