In a message dated 4/11/2010 7:23:39 P.M. Central Standard Time, collinsradio at comcast.net writes: Can anyone tell me a source for the mica insulators on a T0-3 case transistor. David, Digi-Key and Mouser have them. But, how many do you need? I have a bunch as well, glad to send you some. Doug Moore KB9TMY