Description Of Components - Kenwood TK-780 Service Manual

TK-780
SEMOCONDUCTOR DATA / DESCRIPTION OF COMPONENTS
Terminal function (TX-RX unit A/2 IC8)
Pin No. Port Name
1 STB ES
2 SI DT
3 CLK CK
4 Q1 AM1
5 Q2 LOK
6 Q3 STR
7 Q4 DM
8 VSS
9 QS
10
11 Q8 SQ
12 Q7 CODE2
13 Q6 CODE1
14 Q5 OPT
15 OE
16 VDC
Terminal function (TX-RX unit A/2 IC7)
Pin No. Port Name
1 STB ES
2 SI DT
3 CLK CK
4 Q1 HORN
5 Q2 HL
6 Q3 TIMOFF
7 Q4 CODE3
8 VSS
9
10
11 Q8 W/N
12 Q7
13 Q6 PA1
14 Q5 CODE4
15 OE
16 VDC
32
Function
Strobe
DATA
Clock
Audio mute 1. H : Mute, L : Unmute
Link complete.
(Programmable active H/L)
VCO shift switching. H : TX, L : RX
Dead mute. H : RX, L : TX
GND
IC7 data output
NC
External squelch.
(Programmable active H/L)
Option board data 2. H : ON, L : OFF
Option board data 1. H : ON, L : OFF
Option board control.
H : ON, L : OFF / Auxiliary B.
(Programmable active H/L)
Output
+5V.
Function
Strobe
Data
Clock
Horn alert. H : ON, L : OFF /
Auxiliary A. H : ON, L : OFF
RF power switching. H : High, L : Low
Timed power off. H : Power off
Option board data 1. H : ON, L : OFF
GND
NC
NC
Wide/Narrow switching.
H : Wide, L : Narrow
NC
Public address 1. H : ON, L : OFF
Option board data 1. H : ON, L : OFF
Output enable
+5V

DESCRIPTION OF COMPONENTS

TX-RX Unit (A/2)
Ref. No. Use / Function
IC1 DC amp
IC2 DET amp
IC3 Amp/Summing amp
IC4 Analog switch
IC5 A/D converter
IC6 DC amp
IC7 Shift register
IC8 Shift register
IC9 5V AVR
IC10 AF power amp
IC11 FM IF DET
IC12 5V AVR
IC13 9V AVR
IC14 8V AVR
IC15 Flip-flop
IC201 DC amp
IC202 Mixer
IC300 PLL
IC400 Power module
IC401 Short protection
Q1 DC switch
Q2 Ripple filter
Q3 Ripple filter
Q4 HOR switch
Q5 HOR SW control
Q6 HOR SW control
Q7 Buffer amp
Q8 AF mute
Q9 AF mute
Q10 8R SW control
Q11 8R switch
Q12 8T switch
Q13 8T SW control
Q15 IF amp
Q16 DET output level
switch
Q17 PC switch
Q18 DET mute
Q19 APC
Q20 APC
Q21 APC control
Q22 TOF switch
Q23 W/N switch
Operation / Condition
FC, TCXO control
External DEO, internal DEO
DI / DI and MO addtion
DI switch
PC, TV, FC, AFO, BEEP, TO, MO
control
PC
HNC, H/L, TOF, CODE3, CODE4,
PA, W/N control
AM, LOK, STR, DM, OPT, CODE1,
CODE2, SQ control
External 5C
Quadrature detector, 2nd mixer,
OSC, IF amplifier, RSSI
5C
9C
8C
Power on/off control
TV
DBM
Reference 16.8MHz.
PLL lock : LD "H"
RF power 25W
R17 connection and, PTT "H" time
DI off
8CL
9CL
IGN
IGN
HNC "H" time on
HT
AM "H" time on
Power off time on
TR "H" time on
Q10 on time on
Q13 on time on
KEY "H" time on
44.85MHz
Wide time on
TX (8T) time on
KEY "H" time on
APC driver
APC pre-driver
TOF "H" time on
Wide time off