EA3GCY EGV-40 Assembly Manual page 24

Take care and avoid any shortcircuits between bridges.
Q12 capsule (2SC2078) should be electrically isolated from the heatsink. Use the plastic washer and the
mica sheet provided with the kit. Once the transistor is fitted over the heatsink, check with a multimeter
that there is no continuity between the transistor tab, the screw and the heatsink. Use the insulating
material and an M3 screw and nut. It is also recommended to apply a dab of thermal grease.
You may also drill other hole on the heatsink if that suits better its position on your box.
DO NOT OPERATE the transceiver without a heatsink on Q12
EGV-40 CW QRP Transceiver Page 24