Kenwood Tk 780h1 Owners Manual

21
TK-780 / H
INSTALLATION
1-3. Data Equipment Connection
The jumpers must be set to either one for each function.
Otherwise, the radio will not work properly.
AHK/BUSY
R64 (0Ω) R18 (0Ω) Function
Yes No BUSY System busy output indicates if no
repeater channel is available in the
currently selected LTR system
when PTT is pressed, active low
: Default
No Yes AHK MIC hook input.
ME/AM
R12 (0Ω)R167 (0Ω)Function
Yes No AM Speaker mute input, active high
: Default
No Yes ME MIC ground.
MI/TXS
R94 (0Ω) R24 (0Ω)...

22
TK-780/ H
INSTALLATION
ConnectorPin Pin I/O Function
No. No. name
8 SQ O Squelch signal output.  Signal logic
type can select “Carrier operate
relay” or “Tone operate relay”.
Active logic level or type can select
in the KPG-49D.
CN2 1 AM I Audio mute signal input.
LOK O Access logic signal output.  Active
level or type can be selectable in the
KPG-49D.
2 MM I MIC mute input.
3 DTC I Data control channel signal input.
Data channel : L, Normal channel : H
TXS O Signal indicating whether the trans-...

23
TK-780 / H
RSSI
SB
E LOK
C3
C1 C2
FWOP
SQC4 5C RD2
RD1 TD2
TD1
DEO
R571 R529
MPTTPTT
RXAIRXAO
TXAI
TXAO
TX-RX unit (A/2)
Foil side view
INSTALLATION
4. Ignition Sense Cable (KCT-18 : Option)
The KCT-18 is an optional cable for enabling the ignition
function. The ignition function lets you turn the power to the
transceiver on and off with the car ignition key.
If you use the Horn Alert function or the Manual Relay
function, you can turn the function off while driving with the
ignition key.
4-1....

24
TK-780/ H
INSTALLATION
5. Connection Cable (KCT-29 : Option)
The KCT-29 connection cable kit is used to connect the
TK-780/780H transceiver to the KPG-1A Modem GPS Re-
ceiver or the KPG-1B Modem GPS Controller.
5-1. Installing the KCT-29 in the transceiver
1. Remove the upper cover from the transceiver.
2. Lift the DC cord bushing ( 
1 ) from the chassis.
3. Remove the pad as shown in Figure 5 ( 
2 ).
4. Insert the KCT-29 cable ( 
3 ) into the chassis ( 4 ).  The
wire harness band ( 
5 ) must be...

25
TK-780 / H
INSTALLATION
Red
Black
Yellow
GreenA
B
C
ABC
COM1 No Yes Yes
COM2 Yes Yes No
2. Make sure the unit’s power is turned off.
3. Remove the upper case of the transceiver and lift the DC
cable bushing ( 
1 ) from the chassis.
4. Remove the pad as shown in Figure 8 ( 
2 ).
5. Insert the KCT-31 cable ( 
3 ) into the chassis ( 4 ).
The write retaining band ( 
5 ) must be inside the chassis.
6. Replace the DC cable bushing ( 
6 ).
7. Connect the KCT-31 to the TX-RX unit (A/2) as shown in
Figure 9 (...

26
TK-780/ H
INSTALLATION
4
3
2
1
W1
W2
CN1
CN2
KCT-19
Cushion
(G13-1710-04)
CN3CN5
1CN3
Fig. 10
7. PA/HA Unit (KAP-1 : Option)
7-1. Installing the KAP-1 in the Transceiver
The Horn Alert (max. 2A drive) and Public Address func-
tions are enabled by inserting the KAP-1 W1 (3P; white/
black/red) into CN3 on the TX-RX unit (A/2), inserting W2
(3P; green) into CN5 on the TX-RX unit (A/2), and connecting
the KCT-19 (option) to CN2 and CN3 of the KAP-1.
•Installation procedure
1. Open the upper case of the...

27
TK-780 / H
INSTALLATION
9. External Speaker
9-1. KES-3 : Option
The KES-3 is an external speaker for the 3.5-mm-diam-
eter speaker jack.
•Connection procedure
1. Connect the KES-3 to the 3.5-mm-diameter speaker jack
on the rear of the transceiver.
KES-3
Fig. 149-2. KES-4 : Option
The KES-4 is an external speaker used with the acces-
sory connection cable.
•Connection procedure
1. Install the KCT-19 in the transceiver.  (See the KCT-19
section.)
2. Insert the crimp terminal into the square plug...

28
TK-780/ H
Frequency Configuration
The TX-RX unit (A/2) incorporates a VCO, based on a frac-
tional N type PLL synthesizer system, that allows a channel
step of 2.5, 5, 6.25, 7.5kHz to be selected.  The incoming
signal from the antenna is mixed with a first local oscillation
frequency to produce a first intermediate frequency of
44.85MHz.
The signal is then mixed with a second local oscillation
frequency of 44.395MHz to produce a second intermediate
frequency of 455kHz.  This is called a...

29
TK-780 / H

AF Signal System
The detection signal (DEO) from the TX-RX unit (A/2)
goes to the audio processor (IC504) of the TX-RX unit (B/2).
The signal passes through a filter in the audio processor to
adjust the gain, and is output to IC502.  IC502 sums the AF
signal and the DTMF signal and returns the resulting signal
to the TX-RX unit (A/2).  The signal (AFO) sent to the TX-RX
unit (A/2) is input to the D/A converter (IC5).  The AFO out-
put level is adjusted by the D/A converter.  The signal...

30
TK-780/ H

Unlock Circuit
During reception, the TR signal goes high, the KEY signal
goes low, and Q10 turns on.  Q11 turns on and a voltage is
applied to the collector (8R).  During transmission, the TR
signal goes low, the KEY signal goes high and Q13 turns on.
Q12 turns on and a voltage is applied to 8T.
The CPU in the TX-RX unit (B/2) monitors the PLL (IC300)
LD signal directly.  When the PLL is unlocked during trans-
mission, the PLL LD signal goes low.  The CPU detects this
signal and makes the...