TK-380
25
CIRCUIT DESCRIPTION
8. Power Supply Circuit
BB is supplied via a 3A fuse from the battery terminal
connected to the TX-RX unit. After passing through the power
switch, power supply (SB) is applied to the three AVRs. IC5
supplies 5V (5M) to the control circuit, and IC9 supplies 5V
(5C) to common circuits. IC6 supplies to the TX circuit, the RX
circuit and common circuits of needless save mode. During
transmission, 5TC becomes Low and Q3 is turned ON to supply
5V (5T) to the TX circuit. During reception, 5RC becomes Low
and Q2 is turned ON to supply 5V (5R) to the RX Circuit.
9. Optional Board Terminal
Terminals for mounting the option board are provided at
the bottom edge of the TX-RX unit. The table below shows the
correspondence between the board and terminals. R37, R69,
R250, R259, R260, R276, R280 may have to be removed
depending on the type of option board being used.
Name
Function
SB
Battery (7.5V)
GND
Ground
TXD
Serial data
RXD
Serial data
SQ
Busy: high
LOK
Link acquired : low (TX mode)
DI/ANI
Modulation (ANI) input
DEO
Detect output
TXAI/MUTE Modulation output from board or mic mute: low
TXAO
Modulation input to board
RXAI
Received signal input to board
RXAO
Received signal output from board
D1
Binary 1
D2
Binary 2
OPT
Scramble, Emergency:low
PTTIN
PTT switch signal input to board (TX:low)
5CNS
Battery (5V)
DI9
9600 bps data output
RXEMAO
Received signal output from board (after de-
emphasis)
RXEMAI
Received signal input to board (after de-
emphasis)
PTTOUT
PTT switch signal output from board (TX:low)
MONI
Busy:low
LAMP
Busy:low
AAC
Audio Amp Control signal output from board
(Busy:high)
Audio Beep
Beep signal output from board.
AUX TXD
Serial data
AUX RXD
Serial data/Option switch port
/EXT SW
Table 1 Terminal name and function
Fig. 15 Power supply circuit
Display unit
Q2
5RC
5TC
5R
5T
5CNS
IC6
IC9
IC5
Q3
RF power amp (IC100)
+B
F1
SB
ON/OFF
VOL
5M
5C
Summary of Contents for TK-380
Page 33: ...TK 380 33 PARTS LIST ...