pk232.33 Remove the six screws that hold the cover. It won't be necessary to remove the circuit board to install the state machine. Remove the jumper from JP6. If you wish, drill a hole in the front panel just to the left of the word "THRESHOLD" and above the DCD led. The hole size should be correct for the led that you wish to install. The led anode can be tied to any +5 volt source, and a 1000 ohm 1/4 watt resistor is connected in series with the cathode . The other end of this resistor will be connected to the orange wire. This hookup is optional. Connect the wires as follows: BROWN - (+5 volts) - Connect to U8, pin 14. RED - (Ground) - Connect to U17 pin 7. ORANGE - (LED) - Connect to cathode of installed led via a 1000 ohm resistor (described above). YELLOW - (DCD) - Not connected GREEN - ( -DCD) - Connect to center pin of JP6. BLUE - (Clock) - Connect to U8, pin 13 (74LS393). VIOLET - (CD IN) - Connect to the pin on JP6 that is closest to the front panel. GRAY - (NRZI) - Connect to U15, pin 6. Important: If you have the TAPR Modem Disconnect board installed, follow the directions given in the kit's instructions. Insulate the state machine board with some electrical tape, replace cover and put the screws back in . This completes the installation of the state machine board. Operation: Adjust the audio level from the VHF receiver such that the tuning indicator fully spreads on the station with the weakest audio (lowest deviation) on the channel. Set the THRESHOLD control so that ANY station's audio will light the factory DCD LED, as well as noise from unsquelched audio. The DCD LED should go out when there is no signal (squelched audio or full quieting from a carrier). Note: The DCD modification may affect Morse reception at certain speeds. It seems to not affect AMTOR operation or BAUDOT. It is recommended that an additional LED be mounted on the PK-232 front panel per the instructions given. Proper tuning of signals in all modes will be easier if this is done. It is important that the new LED as well as the old DCD LED be illuminated during MORSE and BAUDOT operation for proper decoding by the PK-232. There it is. These are corrections and rewording to the TAPR instructions that came with the DCD state machine. The last paragraph was taken directly from these instructions. 73 Dave, N2DS @ KC2AZ.NY