W9TR
Super Member
There are basically two types of thermal paste. The one for CPU’s is electrically conductive. You don’t want to use it on vintage gear unless you are absolutely certain the transistor case is at ground potential on the heatsink.
The other general purpose paste is electrically non-conductive and works with mica and composite insulators.
The other general purpose paste is electrically non-conductive and works with mica and composite insulators.