Kenwood TK-780 Service Manual Supplement page 25

6-3. Installing the KCT-31 in the transceiver
Note :
When the COM1 is used, A connector is unused.
When the COM2 is used, C connector is unused.
1. Bind the unused connecor to the cable with a retaining
band as shown.
When the COM1 is used.
C
Yellow
Green
B
Red
Black
A
A
COM1 No
COM2 Yes
Fig. 7
Note :
· The modification must be applied to the TK-780/780H
transceivers with a serial number of 30200000 or smaller
when using a COM2 port. Replace the 47k
resistor on the TX-RX unit (B/2) with a 4.7k
Original
47k (RK73GB1J473J)
INSTALLATION
When the COM2 is used.
A
Yellow
Green
B
Red
Black
C
B C
Yes Yes
Yes No
CN4
CN1
C
CN3
CN2
B
CN6
7
When the COM1 is used.
(R675) chip
resistor.
New
4.7k (RK73GB1J472J)
2. Make sure the unit's power is turned off.
3. Remove the upper case of the transceiver and lift the DC
cable bushing ( ) from the chassis.
1
4. Remove the pad as shown in Figure 8 (
5. Insert the KCT-31 cable (
The write retaining band (
6. Replace the DC cable bushing (
7. Connect the KCT-31 to the TX-RX unit (A/2) as shown in
Figure 9 ( ).
7
8. Replace the upper case.
A
CN4
CN1
CN3
CN2
B
CN6
When the COM2 is used.
Fig. 9
· Enable the serial port function on the terminal.
· Refer to the service manual of each radio or the help file
that came with the FPU (Field Programming Unit) for de-
tails.
TK-780/H
).
2
1
2
Fig. 8
) into the chassis ( ).
3 4
) must be inside the chassis.
5
).
6
A
B
5
4
3
6
25