Kenwood TKR-740 Service Manual page 18

TKR-740
*4 AUX I/O 6 and 7 can each be modified to sink up 600mA
of open collector current. The following modification
should be installed when AUX I/O 6 or 7 is used to control
external equipment.
1. Program AUX I/O 6 [7] for "AUX Output" in the KGP-
47D.
2. Remove D32,R84 and R88 for AUX I/O 6 [ D36, R83
and R87 for AUX I/O 7] on the component side of
control unit PCB (see diagram below).
3. Install $Q14, $Q15 and $R154 for AUX I/O 6 [$Q12,
$Q13 and $R153 for AUX I/O 7] on foil side of control
unit PCB (see diagram below).
$Q12,13,14,15
$R153,154
Sub-CPU [IC18]
R83
R87
CN5
Components having those reference numbers marked as
"$" are not used in this transceiver, although they are described
in this service manual for other application purpose.
18
APPLICATION NOTE
DTD114EKA
3.9kΩ (RK73GB1J392J) chip resistor
5V
Add $R154 [$R153]
3.9k
Add $Q14 [$Q12]
DTD114EKA
Remove
R84 [R83]; 0
Front
R84
R88
CN6
Rear
Component Side
4. Change R320 for AUX I/O 6 [R319 for AUX I/O 7]
from 1kΩ (RK73GB1J102J) to 0Ω (R92-1252-05).
By making this modification, AUX I/O 6 and 7 can now sink up
to 600mA each.
5V
R313 [R312]
47k
Remove D32 [D36]
Add $Q15 [$Q13]
DA204U
DTD114EKA
Remove
R88 [R87]; 0
Remote I/O
AUX I/O 6 [7]
R320 [R319]
Change 1k to 0
Front
$Q12 $Q14
$R153 $R154
$Q13 $Q15
Rear
Foil Side