Small Wonder Labs
PSK-20 Transceiver Kit 03/09/10
2000
12
ASSEMBLY INSTRUCTIONS:
The following components are pre-mounted on the
board:
U8 (MAR-3 IC)
All components should be mounted on the
silkscreened side of the board. Solder
components into place and trim leads after
installation unless otherwise noted .
You
may find it convenient to install 3-4 parts at a
time between soldering operations.
Group 1 Assembly:
Group 1 assembly installs the DC power and serial
port connectors, biasing and T-R switching circuitry.
Install the 9-pin (DB-9) serial port connector
at J4.
Install the DC power jack (black, 3 tabs) at J5.
Note: there will be 'play' in the orientation of
this part due to the slot widths - make sure it
is carefully aligned square to the board edges
before soldering all three tabs.
Install diode D12 (1N4001) immediately
below J5. Match the installation orientation as
shown on the silkscreen.
Install electrolytic capacitor C120 (220 UF).
Note: there is no silkscreened reference
designator for this part.
Observe the
polarity marking on the device- the dark bar
down one side of the part denotes the negative
lead. Note that the longer of the two capacitor
leads is (+).
Install diodes D16 and D17 (1N4148s, below
J4). Match the installation polarity as shown
on the silkscreen.
Install disk cap C110 (.01 uF), '103'
Install disk cap C124 (.01 uF).
Y10 is shown
on the group 1 drawing for reference/locating
purposes and is not installed at this time.
Install an 8-pin IC socket at U5. Match the
'notch' orientation as shown on the silkscreen.
Install resistor R25 (10K, brn/blk/org).
Install resistor R27 (10K, brn/blk/org).
Install resistor R29 (10K, brn/blk/org).
Install resistor R28 (22K, red/red/org).
Install resistor R30 (4.7K, ylw/violet/red).
Install resistor R32 (4.7K, ylw/violet/red).
Install resistor R31 (47K, ylw/violet/org).
Install resistor R26 (22K, red/red/org).
Install disk caps C111, C112 (.01 uF, '103')
Install electrolytic capacitor C21 (1 uF).
Observe the polarity marking on the device.
Install diode D7 (1N4148- from tape strip).
Match the orientation of the banded end of the
component to that of the silkscreen.
Install transistor Q3 (2N3906). Match the
orientation of the flat side of the component
to that of the silkscreen.
Install 3-pin IC U9 (78L08). Match the
orientation of the flat side of the component
to that of the silkscreen.
(L3)
D12
J5
PWR.
U5
C21
R30
R28
C111
4.7K
1
0
K
22K
R27
10K
- +
1 uF
C
1
2
4
.01
+ -
220 uF
C120
U9
Q3
C112
.01
10K
R
2
5
J4
.01
C110
R32
R31
D7
4.7K
47K
22K
R26
D16
D17
(r
e
f.
o
n
ly
)
(Y10)
(ref. only)
R29
