Heathkit SB-401 Assembly Manual page 29

Detail 3-30
Detail 3-3C
#4 LOCKWASHERt
4-40 NUT~
4-40xS/16
tt
SCREW
( ) Install the mixer-bandpass circuit board
(4185-154-1). Use 4-40 x 5/16" hardware
only in the five holes indicated
by
the arrows.
The remaining hardware will be installed
later. CAUTION: Refer to Detail 3-3D and
check the circuit board and be sure that
none·of the points indicated by arrows touch
the chassis.
If
they do, loosen the hardware
and reposition the circuit board.
( ) Refer to Detail 3-3C, and install the car-
rier generator circuit board (#85 - 76 - 3)
with a pilot lamp socket at TR. Use 4-40 x
5/16" hardware only in the eight holes indi-
cated by the arrows shown in Pictorial 3.
The remaining hardware will be installed
later.
NOTE: Any solder around the edge of either
circuit board which will keep the board from
fitting flush against the chassis must be re-
moved before the circuit board is mounted.
Detail 3-38
( ) Refer to Detail 3-3B, and lightly sand the
outside foil of the two circuit boards.
This will remove the protective finish and
provide good grounding between the circuit
boards and the chassis.
r "'\
-
\
\
FOIL SIDE OF CIRCUIT BOARD
Page 25