Small Wonder Labs
PSK-20 Transceiver Kit 03/09/10
2000
21
Note:
The
following
components
have
no
silkscreened reference designators:
C121, C122, R57, D14
Note their placement carefully with respect to
nearby silkscreened component outlines
before installing and soldering.
Install C39 and
C121
(.1 uF monolithic caps,
'104').
Install
C122
(.01 uF disk cap)
Install
R57
(2.2K, red/red/red).
Install D13 and
D14
(1N4148). Observe the
installation polarity as shown on the
silkscreen.
Install the BNC connector.
Install R54 through R56 (1.5
Ω
,
brown/green/gold).
Using a small screwdriver blade (or 8-10d
common nail) as a 'form', bend the 3 leads
downward at a 90
°
angle as shown,
immediately.outboard of the wide portion of
the leads
. Take care to ensure the resulting
bent leads are uniformly distant from the
transistor body.
Place the heat sink on the board, insert Q11's
three leads into the corresponding holes in the
board.
(Do not solder yet.)
Place the 1/4"
(6.3mm) machine screw through the hole in
the transistor tab and through the heatsink and
printed circuit board. Secure in place with a
nylon nut. Make sure that the heat sink is
aligned parallel with the board before
tightening the nut.
Tighten cautiously- the
nylon nut threads will strip at the torque
typically used for steel hardware
.
Solder
Q11's leads into place.
Caution: do not substitute a metallic nut here!
You may find it easier to pin the transistor
and heat sink together with the machine
screw, using a fingertip to hold the screw
down while inserting the transistor leads into
the board.
BNC
T2
L
1
2
L13
C
1
2
2
J5
C43
C41
C40
C42
.01
150
330
330
150
.1
R57
D14
2.2K
J6
.1
C39
+ -
D13
T
P
2
Q11
C121
L11
That's it- board assembly is complete
!
CLEAN UP YOUR ACT!
Before you proceed to
checkout, grab some cotton swabs and use acetone
(nail polish remover) to remove solder flux from the
foil-side of the PC board. The result is a much cleaner
appearance once you've completed this step.
