Specifications

8
.Installation with a DSP Daughterboard
Connections
Follow the next steps to connect the wires from the back panel as shown in Figure A and B.
1) Connect PSK enable J5 on PSK board (grey wire) to PB0 (hole from lead of R253 closest to left side
of PK-900).
2) Connect J1 (+12V) (red wire) to D21 (1N4004 smaller diode on the left closest to the heatsink)
anode lead on PK-900 main board. The anode lead is toward the front of the PK-900 and is the end
of the diode
without the light-colored band on the body of the diode. Wrap the stripped wire lead
from J1 around the lead of the diode as far as possible from the body of the diode. Solder the two
leads together.
3) Connect J6 (GND) (black wire) to to the solder lug on the top of the DC power jack on PK-900 main
board.
4). Connect J2 (RX Audio in) (violet wire) to C89 Rear Pad on PK-900 main board.
5) Connect J3 (RX audio out) (white wire) to the pad on the PK-900 DSP board labeled “C89 Rear”.
6). Connect J7 (TX audio in) (brown wire) to the C40 left pad on PK-900 Main board.
7). Connect J4 (TX Audio out) (orange wire) to the C40 right pad on PK-900 main board.
8) If you have one, re-install the 9600 baud board. Be very careful not to bend the 20 pins on the bottom
of the board. Fasten the board with the four screws removed when the board was temporaily re-
moved. All the leads from the PSK board should be under the 9600 baud board. Do not pinch any
wires under the board standoffs or sockets.
9) Fasten the new back panel assembly to the bottom cover of the PK-900 with 3 screws removed with
the old back panel.
10) Secure the chassis top with all 4 screws.
11) Place the enclosed sticker (PSK) below the raised “AEA” logo on the left side of the front
panel of the PK-900. Place it one inch above the bottom edge of the panel.
12) Reconnect the unit and reset when powering on for the first time.